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Conserving Marine Biodiversity in South Australia - Part 2 - Identification of areas of high conservation value in South Australia K S Edyvane May 1999 ISBN 0 7308 5238 5 No 39 The recommendations given in this publication are based on the best available information at the time of writing. The South Australian Research and Development Institute (SARDI) makes no warranty of any kind expressed or implied concerning the use of technology mentioned in this publication. © SARDI. This work is copyright. Apart of any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the publisher. SARDI is a group of the Department of Primary Industries and Resources CONTENTS – PART TWO PAGE NUMBER CONTENTS INTRODUCTION 1 1.1 Introduction ----------------------------------------- i The Hierarchical Nature of Biodiversity -------------------------------------------------1.2 Classifying Marine Ecosystems – Bioregionalisation ---------------------------------------------1.3 Defining a Marine Bioregional Planning Framework for South Australia----------------------1.4 IMCRA – A National Template for Marine Biodiversity and Ecosystem Management------1.5 ‘Province’ or Large Marine Ecosystem Regionalisation------------------------------------------1.6 ‘Bioregion’ or Ecosystem – Level Regionlisation -------------------------------------------------1.7 ‘Biounit’ or Habitat – Level Regionalisation -------------------------------------------------1.8 Criteria for Identifying Areas of Conservation Significance -------------------------------------APPENDIX ONE -------------------------------------------------- i iii iii vi vii viii viii xvi xviii EYRE COAST REGION ----------------------------------------- 1 MARINE BIOGEOGRAPHY ----------------------------------------- 2 The Eyre Coast -------------------------------------------------Biogeography of the Eyre Coast -------------------------------------------------Oceanography ----------------------------------------------------------------------------------------Wave Climate -------------------------------------------------Water Temperature and Salinity ---------------------------------------------------------------------Currents and Upwellings -----------------------------------------------------------------------------Climate -------------------------------------------------------------------------------------------------Coastal Geomorphology and Landforms--------------------------------------------------------Biology--------------------------------------------------------------------------------------------------Intertidal Ecology--------------------------------------------------------------------------------------Subtidal Ecology---------------------------------------------------------------------------------------Fish ------------------------------------------------------------------------------------------------------Seabirds -------------------------------------------------------------------------------------------------Marine Mammals --------------------------------------------------------------------------------------- 2 2 3 3 3 3 4 4 5 5 5 8 8 8 MARINE CONSERVATION VALUES ----------------------------------------------- 9 1 1.1 1.2 2 2.1 2.2 3 9 9 1 1.1 2 2.1 2.2 2.3 3 4 5 5.1 5.2 5.3 5.4 5.5 Significant Biological and Physical Features ------------------------------------------------------Biological-----------------------------------------------------------------------------------------------Physical -------------------------------------------------------------------------------------------------Significant Cultural and Historical Features ---------------------------------------------------Aboriginal ----------------------------------------------------------------------------------------------European------------------------------------------------------------------------------------------------Current Conservation Status of the Eyre Coast ----------------------------------------------------- 12 12 14 15 I NULLARBOR BIOUNIT --------------------------------------------------------MARINE BIOGEOGRAPHY ----------------------------------------------------------- 16 16 1 2 3 16 16 16 17 17 17 19 20 20 21 21 22 22 Oceanography ----------------------------------------------------------------------------------------Geology and Coastal Geomorphology------------------------------------------------------------Biology--------------------------------------------------------------------------------------------------- MARINE CONSERVATION VALUES ----------------------------------------------1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 Significant Biological and Physical Features ------------------------------------------------------Biological-----------------------------------------------------------------------------------------------Physical -------------------------------------------------------------------------------------------------Other Values -------------------------------------------------------------------------------------------Commercial Fisheries ---------------------------------------------------------------------------------Mariculture ---------------------------------------------------------------------------------------------Recreation and Tourism ------------------------------------------------------------------------------Scientific Research and Education ------------------------------------------------------------------Adjacent Land Use ------------------------------------------------------------------------------------- 11 CONTENTS – PART TWO PAGE NUMBER CONTENTS 2.5 Significant Cultural and Historical Features -------------------------------------------------- 22 3 4 Current Conservation Status of the Nullarbor Biounit ---------------------------------------Areas of High Conservation Value in the Nullarbor Biounit --------------------------------- 22 23 II WAHGUNYAH BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Mariculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Wahgunyah Biounit ------------------------------------Areas of High Conservation Value in the Wahgunyah Biounit------------------------------- III FOWLERS BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Mariculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Fowlers Biounit ------------------------------------------Areas of High Conservation Value in the Fowlers Biounit ------------------------------------ 24 24 24 24 24 25 25 25 25 25 25 26 26 26 26 26 27 27 28 28 28 28 28 29 29 29 29 29 29 30 30 30 31 31 31 32 CONTENTS – PART TWO PAGE NUMBER CONTENTS IV STREAKY AND NUYTS BIOUNITS -----------------------------------MARINE BIOGEOGRAPHY ----------------------------------------1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- 33 33 33 34 ----------------------------------------- 35 Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Mariculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Streaky and Nuyts Biounit ----------------------------Streaky Biounit -------------------------------------------------Nuyts Biounit -------------------------------------------------Areas of High Conservation Value in the Streaky and Nuyts Biounit ---------------------Streaky Biounit -------------------------------------------------Nuyts Archipelago -------------------------------------------------- 35 35 37 38 38 39 40 40 40 41 42 42 42 42 42 43 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 3.1 3.2 4 4.1 4.2 33 V YANERBIE BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES ----------------------------------------- 45 45 45 45 45 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Yanerbie Biounit ----------------------------------------- 46 46 46 48 48 48 48 49 49 49 49 49 4 Areas of High Conservation Value in the Yanerbie Biounit ---------------- 50 CONTENTS – PART TWO CONTENTS --------------------------------- PAGE NUMBER VI NEWLAND BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Mariculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Newland Biounit-----------------------------------------Areas of High Conservation Value in the Newland Biounit ----------------------------------- VII SHERINGA AND FLINDERS BIOUNITS ----------------------------MARINE BIOGEOGRAPHY ----------------------------------------1 2 3 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 3.1 3.2 4 4.1 4.2 ---------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Sheringa and Flinders Biounits ----------------------Sheringa Biounit -------------------------------------------------Flinders Biounit -------------------------------------------------Areas of High Conservation Value in the Sheringa and Flinders Biounits----------------Sheringa Biounit -------------------------------------------------Flinders Biounit -------------------------------------------------- 51 51 51 51 51 52 52 52 53 53 53 54 54 54 54 55 55 55 56 56 56 56 57 57 57 57 59 59 59 60 60 61 61 62 62 62 62 63 63 63 CONTENTS – PART TWO PAGE NUMBER CONTENTS VIII DOUGLAS BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Douglas Biounit------------------------------------------Areas of High Conservation Value in the Douglas Biounit ------------------------------------ IX WHIDBEY BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Whidey Biounit ------------------------------------------Areas of High Conservation Value in the Whidbey Biounit----------------------------------- SPENCER GULF REGION 65 65 65 65 65 66 66 66 68 68 68 68 70 70 70 71 71 71 72 72 72 72 73 73 73 73 75 75 75 76 76 76 76 77 77 77 ------------------------------------------- 79 MARINE BIOGEOGRAPHY ----------------------------------------- 1 1.1 2 2.1 2.2 2.3 3 4 --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 80 80 80 80 80 81 81 81 81 Spencer Gulf Biogeography of the Spencer Gulf Oceanography Wave Climate Water Temperature and Salinity Currents Climate Coastal Geomorphology and Landforms CONTENTS – PART TWO PAGE NUMBER CONTENTS 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Biology General Marine Ecology Intertidal Ecology Subtidal Ecology Seagrass Ecology Fish Marine Mammals Seabirds MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 3 --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 82 82 82 83 84 85 85 86 ----------------------------------------- 87 87 87 89 89 89 90 91 Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Aboriginal -------------------------------------------------European -------------------------------------------------Current Conservation Status of the Spencer Gulf ---------------------------------------------- X JUSSIEU BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Jussieu Biounit-------------------------------------------Areas of High Conservation Value in the Jussieu Biounit 92 92 92 92 93 94 94 94 97 97 97 98 99 100 100 101 102 102 CONTENTS – PART TWO PAGE NUMBER CONTENTS XI DUTTON BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 104 1 Oceanography -------------------------------------------------2 Geology and Coastal Geomorphology -------------------------------------------------3 Biology -------------------------------------------------MARINE CONSERVATION VALUES -------------------------------------------------1 Significant Biological and Physical Features -------------------------------------------------1.1 Biological -------------------------------------------------1.2 Physical -------------------------------------------------2 Other Values -------------------------------------------------2.1 Commercial Fisheries -------------------------------------------------2.2 Aquaculture -------------------------------------------------2.3 Recreation and Tourism -------------------------------------------------2.4 Scientific Research -------------------------------------------------2.5 Adjacent Land Use -------------------------------------------------2.6 Significant Cultural and Historical Features -------------------------------------------------3 Current Conservation Status of the Dutton Biounit -------------------------------------------- 104 104 104 104 104 104 104 104 105 105 105 105 106 106 106 106 4 106 Areas of High Conservation Value in the Dutton Biounit ------------------- XII FRANKLIN BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Franklin Biounit-----------------------------------------Areas of High Conservation Value in the Franklin Biounit ----------------------------------- 107 107 107 107 108 108 108 108 109 109 109 110 111 111 111 111 111 111 CONTENTS – PART TWO PAGE NUMBER CONTENTS XIII YONGA BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- 113 113 113 113 ----------------------------------------- 114 Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Yonga Biounit--------------------------------------------Areas of High Conservation Value in the Yonga Biounit -------------------------------------- 114 114 116 116 116 117 117 118 118 118 118 118 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 XIV WINNINOWIE BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Winninowie Biounit-------------------------------------Areas of High Conservation Value in the Winninowie Biounit------------------------------- 113 120 120 120 120 120 121 121 121 123 124 124 124 125 125 125 125 125 126 CONTENTS – PART TWO PAGE NUMBER CONTENTS XV TIPARRA BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES ----------------------------------------- 1 1.1 1.2 ---------------------------------------------------------------------------------------------------------------------------------------------------- Significant Biological and Physical Features Biological Physical MARINE CONSERVATION VALUES 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Tiparra Biounit ------------------------------------------Areas of High Conservation Value in the Tiparra Biounit ------------------------------------ XVI WARDANG BIOUNITS MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Wardang Biounit ----------------------------------------Areas of High Conservation Value in Wardang Biounit--------------------------------------- 127 127 127 127 127 128 128 128 128 128 128 128 129 129 130 130 130 130 130 132 132 132 132 132 133 133 133 133 133 133 134 134 135 135 135 136 136 CONTENTS – PART TWO PAGE NUMBER CONTENTS XVII PONDALOWIE BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Values -------------------------------------------------Current Conservation Status of the Pondalowie Biounit -------------------------------------Areas of High Conservation Value in the Pondalowie Biounit ------------------------------- XVIII GAMBIER BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES ----------------------------------------- 1 1.1 1.2 ---------------------------------------------------------------------------------------------------------------------------------------------------- Significant Biological and Physical Features Biological Physical MARINE CONSERVATION VALUES 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Gambier Biounit-----------------------------------------Areas of High Conservation Value in the Gambier Biounit----------------------------------- 137 137 137 137 137 138 138 138 138 138 138 139 139 140 140 140 140 141 142 142 142 142 142 142 142 142 143 143 143 143 144 144 144 144 144 144 145 CONTENTS – PART TWO PAGE NUMBER CONTENTS GULF OF ST VINCENT – FLEURIEU PENINSULA REGION ------------------ 146 MARINE BIOGEOGRAPHY ----------------------------------------- 1 1.1 Gulf St Vincent – Fleurieu Peninsula Biogeography of Gulf St Vincent - Fleurieu Peninsula Oceanography Wave Climate Water Temperature and Salinity Currents Climate Coastal Geomorphology and Landforms Biology General Ecology Subtidal Ecology Seagrass Ecology Fish Marine Mammals -------------------------------------------------- 147 147 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 147 148 148 148 148 148 149 150 150 151 152 153 153 MARINE CONSERVATION VALUES ----------------------------------------- 154 154 154 156 156 156 156 157 2 2.1 2.2 2.3 3 4 5 5.1 5.2 5.3 5.4 5.5 1 1.1 1.2 2 2.1 2.2 3 Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Aboriginal -------------------------------------------------European -------------------------------------------------Current Conservation Status of Gulf St Vincent – Fleurieu Peninsula --------------------- XIX STURT AND INVESTIGATOR BIOUNITS --------------------------MARINE BIOGEOGRAPHY ----------------------------------------1 2 3 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ---------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Sturt and Investigator Biounits ----------------------Areas of High Conservation Value in the Sturt Biounits -------------------------------------- 159 159 159 159 159 160 160 160 161 161 161 162 162 163 163 164 164 164 CONTENTS – PART TWO PAGE NUMBER CONTENTS XX ORONTES BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Orontes Biounit------------------------------------------Areas of High Conservation Value in the Orontes Biounit ------------------------------------ XXI CLINTON BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of Clinton Biounit -----------------------------------------------Areas of High Conservation Value in the Clinton Biounit------------------------------------- 166 166 166 166 166 167 167 167 167 167 167 168 169 169 170 170 170 171 172 172 172 172 172 173 173 173 176 176 176 176 177 177 178 179 179 180 CONTENTS – PART TWO PAGE NUMBER CONTENTS XXII YANKALILLA BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Yankalilla Biounit---------------------------------------Areas of High Conservation Value in the Yankalilla Biounit --------------------------------- XXIII ENCOUNTER BIOUNIT MARINE BIOGEOGRAPHY OCEANOGRAPHY --------------------------------------------------------------------------------------------------------------------------- 2 3 --------------------------------------------------------------------------------------------------- Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Encounter Biounit---------------------------------------Areas of High Conservation Value in the Encounter Biounit--------------------------------- 181 181 181 181 181 182 182 182 184 184 184 185 185 187 187 188 188 189 190 190 190 190 190 191 191 191 193 194 194 195 195 196 196 197 198 198 CONTENTS – PART TWO PAGE CONTENTS NUMBER KANGAROO ISLAND COAST ------------------------------------------- 199 MARINE BIOGEOGRAPHY ----------------------------------------- 1 1.1 2 2.1 2.2 2.3 3 4 5 5.1 5.2 5.3 5.4 5.5 5.6 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 199 200 200 201 201 201 201 202 202 202 202 203 204 204 204 204 Kangaroo Island Biogeography of Kangaroo Island Oceanography Wave Climate Water Temperature and Salinity Currents and Upwellings Climate Geology and Coastal Geomorphology Biology General Ecology Marine Flora Fish Reptiles Seabirds Marine Mammals MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 3 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Aboriginal -------------------------------------------------European -------------------------------------------------Current Conservation Status of the Kangaroo Island Coast---------------------------------- XXIV NEPEAN AND BACKSTAIRS BIOUNITS ----------------------------MARINE BIOGEOGRAPHY ----------------------------------------1 2 3 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ---------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Nepean and Backstairs Biounits ---------------------Areas of High Conservation Value in the Nepean and Backstairs Biounits---------------- 205 205 205 207 207 207 207 208 209 209 209 209 209 210 210 210 213 214 214 215 215 216 216 216 217 217 CONTENTS – PART TWO PAGE NUMBER CONTENTS XXV GANTHEAUME BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 Oceanography -------------------------------------------------2 Geology and Coastal Geomorphology -------------------------------------------------3 Biology -------------------------------------------------MARINE CONSERVATION VALUES -------------------------------------------------1 Significant Biological and Physical Features -------------------------------------------------1.1 Biological -------------------------------------------------1.2 Physical -------------------------------------------------2 Other Values -------------------------------------------------2.1 Commercial Fisheries -------------------------------------------------2.2 Aquaculture -------------------------------------------------2.3 Recreation and Tourism -------------------------------------------------2.4 Scientific Research and Education -------------------------------------------------2.5 Adjacent Land Use -------------------------------------------------2.6 Significant Cultural and Historical Features -------------------------------------------------3 Current Conservation Status of the Gantheaume Biounit------------------------------------4 Areas of High Conservation Value in the Gantheaume Biounit------------------------------ XXVI CASSINI BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Cassini Biounit-------------------------------------------Areas of High Conservation Value in the Cassini Biounit ------------------------------------- 219 219 219 219 220 220 220 220 223 223 223 224 225 225 226 226 226 227 229 229 229 229 229 230 230 230 230 231 231 231 232 232 232 233 233 233 CONTENTS – PART TWO PAGE NUMBER CONTENTS SOUTH EAST COAST MARINE BIOGEOGRAPHY 1 1.1 2 2.1 2.2 2.3 2.4 3 4 4.1 4.2 4.3 4.4 4.5 5 5.1 5.2 5.3 5.4 5.5 MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 3 ----------------------------------------- The South East Coast -------------------------------------------------Biogeography of the South East Coast -------------------------------------------------Oceanography -------------------------------------------------Wave Climate -------------------------------------------------Water Temperature and Salinity -------------------------------------------------Currents and Upwellings -------------------------------------------------Groundwater Drainage -------------------------------------------------Climate -------------------------------------------------Coastal Geomorphology and Landforms -------------------------------------------------Outer Dune Barrier Complexes of Younghusband Peninsula and Robe ------------------------Beach-Ridge Plains of Lacepede, Guichen and Rivoli Bays -------------------------------------Coorong and Robe Range - Woakwine Range Despressions-------------------------------------Stranded Pleistocene Barriers and Relict Coast of the Robe Range Outer Barrier ------------Tertiary Limestone Plain of the Lower South East ------------------------------------------------Biology -------------------------------------------------General Ecology -------------------------------------------------Subtidal Ecology -------------------------------------------------Fish -------------------------------------------------Seabirds -------------------------------------------------Marine Mammals -------------------------------------------------- ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Aboriginal -------------------------------------------------European -------------------------------------------------Current Conservation Status of the South East Coast ----------------------------------------- 236 236 236 237 237 237 257 237 238 238 238 238 238 238 239 239 239 239 240 241 241 241 241 241 242 242 243 243 243 CONTENTS – PART TWO PAGE NUMBER CONTENTS XXVII COORONG BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Coorong Biounit -----------------------------------------Areas of High Conservation Value in the Coorong Biounit ----------------------------------- XXVIII CANUNDA BIOUNIT MARINE BIOGEOGRAPHY ----------------------------------------------------------------------------------- 1 2 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Canunda Biounit ----------------------------------------Areas of High Conservation Value in the Canunda Biounit ---------------------------------- 244 244 244 244 245 245 245 245 248 248 248 249 249 249 249 250 251 251 252 252 252 252 252 253 253 253 255 256 256 257 257 258 258 258 259 260 CONTENTS – PART TWO PAGE NUMBER CONTENTS XXIX NENE AND PICCANINNIE BIOUNITS -------------------------------MARINE BIOGEOGRAPHY ----------------------------------------1 2 3 Oceanography Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 2.6 3 4 ---------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------- Significant Biological and Physical Features -------------------------------------------------Biological -------------------------------------------------Physical -------------------------------------------------Other Values -------------------------------------------------Commercial Fisheries -------------------------------------------------Aquaculture -------------------------------------------------Recreation and Tourism -------------------------------------------------Scientific Research and Education -------------------------------------------------Adjacent Land Use -------------------------------------------------Significant Cultural and Historical Features -------------------------------------------------Current Conservation Status of the Nene and Piccaninnie Biounits -----------------------Areas of High Conservation Value in the Nene and Piccaninnie Biounits------------------ BIBLIOGRAPHY ----------------------------------------- 262 262 262 262 262 263 263 263 265 265 265 266 266 266 267 267 268 268 269 CONTENTS – PART TWO ACKNOWLEDGMENTS This project has been supported by Environment Australia under the Natural Heritage Trust (Marine Protected Areas Program) and the former ‘Ocean Rescue 2000 Program’ and represents the culmination of technical and policy development first conducted by SARDI (formerly the SA Department of Fisheries) in 1991/92. In the latter stages of this project, the information from the ‘SA Marine Biodiversity Program’ provided essential information in the definition of areas of high conservation value, and in defining the marine ecological regions of South Australia. This work would not have been possible without the support of: • • • • • • • • • • • Environment Australia, which provided funding specifically for this project during 1991/92 and 1995/96; Deborah Nias, who provided technical summaries of the South East and Kangaroo Island regions and also, project assistance during 1992; Participants of the ‘SA Marine Protected Areas Workshop’ held in November 1991, who identified key areas of high conservation value and potential Marine Protected Area sites; For digitising and map production (Part 2 of the report): Russell Flavel and Megan Tutty (Geographical Systems Unit, PIRSA); and Tim Noyce, Belinda Hille (Geographical Analysis and Research Unit, Department of Transport, Urban Planning and the Arts) and Lyn Scott (SARDI); Janine Baker (SARDI) and Dr. Hugh Kirkman (CSIRO, Division of Marine Research), who, since 1993 have been major collaborators on the SA Marine Biodiversity Program; The master (N Chigwidden) and crew (D Kerr, N Wigan, C Foulkes) of the MRV Ngerin, and technical officers (A Dalgetty, V Boxall, B Davies) who provided invaluable field support for the marine biological surveys; Graham Edgar for providing most of the slides for the cover; CSIRO (Vince Lyne) for providing the satellite image of SA waters; Jon Bryan for providing slides for the cover; Ken Hoppen for providing the "Moonlighter" slide for the cover; The Marine and Coastal Community Network (MCCN) for providing the slide of the Australian Sea Lion. Finally, I would like to acknowledge the personal support of my colleagues at SARDI (Aquatic Sciences), particularly Dr Scoresby Shepherd, Annette Doonan and Suyin Deakin. Dr Karen Edyvane 14 August 1998 The views and opinions expressed in this document are those of the author and do not necessarily reflect the view or position of SARDI, PIRSA or the South Australian Government. Neither do they reflect those of the Australian Commonwealth Government or the Minister of the Environment. Collation of the information presented in this report was undertaken with funding provided by the Australian National Conservation Agency (now Environment Australia) for the Ocean Rescue 2000 Marine Protected Areas Program (Project number OR52). Copyright in this report is vested in the Chief Executive, Primary Industries and Resources South Australia. The report may be cited as: Edyvane, K S (1999). Conserving Marine Biodiversity in South Australia - Part 2 - Identification of areas of high conservation value in South Australia. INTRODUCTION – PART TWO INTRODUCTION 1 INTRODUCTION 1.1 The Hierarchical Nature of Biodiversity In conserving marine biodiversity it is important to recognise the hierarchical nature of ecosystems, biodiversity and ecological processes. Biological diversity can be defined at the ecosystem, seascape/landscape, species and genetic level. Marine and coastal systems are extraordinarily diverse at all these levels. However, due to the inaccessible nature of the marine environment and the lack of knowledge of marine biodiversity at the species level, the measurement of biodiversity in marine environments is generally most approachable and practical at the level of the seascape or habitat. In the marine environment, biodiversity occurs at the scale of large marine ecosystems, such as major oceanic and pelagic ecosystems, and is defined by large-scale processes such as oceanography (ie. currents, upwellings), trophodynamics, coastal physiography and basin topography. Similarly, biodiversity also occurs at the smaller scales of ecosystems (eg. open coasts, gulfs), habitats (eg. reefs, estuaries, bays) and biological communities (eg. mangroves, seagrasses, kelp forests, coral reefs). At these scales, patterns in biodiversity may be dominated by small-scale physical processes such as type of substratum, cyclones, storm events, changes in wave exposure, or biological processes such as competition and predation. In conserving the full range of South Australia’s marine biodiversity needs to be conserved, from the large marine ecosystems, to the habitat and communitylevel patterns of biodiversity. What is Biological Diversity ? The National Strategy for the Conservation of Australia’s Biological Diversity (1996) defines biological diversity as the variety of all life forms – the different plants, animals, microorganisms, the genes they contain, and the ecosystems of which they form a part. It is not static, but constantly changing; it is increased by genetic change and evolutionary processes and reduced by processes such as habitat degradation, population decline, and extinction. The concept emphasises the interrelatedness of the biological world. It covers the terrestrial, marine and other aquatic environments. Biological diversity can be considered at three fundamental levels: • − Genetic diversity: the variety of genetic information contained in all of the individual plants, animals and microorganisms that inhabit the earth. Genetic diversity occurs within and between the populations of organisms that comprise individual species as well as among species. • − Species diversity: the variety of species on earth. • − Ecosystem diversity the variety of habitats, biotic communities and ecological processes. Marine biodiversity conservation in South Australia also needs to take account of coastal and oceanographic change over geological time scales, particularly with respect to the evolution of the coastal and marine environment and also, land-sea dynamics (Ray 1991). For temperate southern Australia, a long period of geological and continental isolation has resulted in high endemism in the marine biota (Edyvane 1996), while continental drift and periods of global warming and cooling have resulted in significant intrusions of warm water from the Indo-Pacific, and importantly, significant sea level changes. In South Australia, the gulfs region are particularly significant, containing not only high levels of endemism, but also, a subtropical element in the marine flora and fauna. Ecological processes, resource distributions and human impacts can also can be understood, conserved and managed at a range of spatial and temporal scales. Because of the nested hierarchical structure of ecosystems, marine management (including the establishment and management of Marine Protected Areas) needs to examine and occur within several temporal and spatial scales (Ray & McCormick-Ray 1992). The adoption of a scale-adapted approach to environmental management and planning requires both, an understanding of the spatio-temporal hierarchies of patterns and processes in natural systems, and also, a recognition of the scales of human impact, monitoring and management inherent in humanecosystem interactions (see Table 1.1). i INTRODUCTION – PART TWO SCALES OF HUMAN-MARINE ECOSYSTEM INTERACTION SCALE ECOSYSTEM MAJOR PROCESSES HUMAN IMPACTS MANAGEME NT Global Biosphere topography (ocean basins), oceanography, climate (large-scale) global warming, sealevel changes international 1000’s kms bioprovince topography (large-scale), oceanography (major currents, temperature), climate global warming, sealevel changes, ecosystem stress, reduced biodiversity international 100’s kms bioregion topography, oceanography (upwellings, small currents), sediment supply pollution, habitat fragmentation, overfishing, species loss, ecosystem stress, reduced biodiversity national/state 10’s kms biounit topography, aspect (exposure), tides, storms, sediment supply pollution, habitat loss, overfishing, population loss, exotic introductions, ecosystem effects local 1-10’s km habitat aspect (exposure), storms, community dynamics, tides, depositional processes pollution, habitat loss, overfishing, aquaculture, dredging, population loss, exotic introductions, ecosystem effects local 100’s metres site depth, predation, competition, storms pollution, habitat loss, aquaculture, dredging population loss, exotic introductions local Table 1.1 Scales of human-marine ecosystem interactions (ie patterns, processes, human impacts and management) (from Edyvane 1996). ii INTRODUCTION – PART TWO 1.2 Classifying Marine Bioregionalisation Ecosystems - 1.3 Defining a Marine Bioregional Planning Framework for South Australia `Bioregionalisation’, or the definition of biogeographic regions, is not only an essential step in marine conservation planning, but also, is essential in defining a bioregional planning framework for ecosystem management (Salm & Clarke 1984, ACIUCN 1986, Sherman et al. 1990, Ray & McCormick-Ray 1992, Bridgewater & Ivanovici 1993). In natural ecosystems, an understanding of the patterns of biodiversity, particularly habitat biodiversity, is not only essential for identifying an ecologically or biogeographically representative system of protected areas, but is also essential in defining scaled ecological units for holistic, integrated management at the ecosystem level (ie. catchment, landscape or `seascape management’) (Forman & Godron 1986, Urban et al. 1987, Kessler et al. 1992, Grumbine 1994, Klijn 1994). Importantly, the scale and extent to which different human activities affect either biodiversity and/or ecological processes, determines both, the scale and nature of management and monitoring required, and hence, defines the framework for integrated, ecosystem management. As such, biogeographical regions or `bioregions’ provide the boundaries and framework for biodiversity or conservation management and the multiple-use management of other specific human activities or uses, such as fisheries, mining, and tourism. Planning, including identification of priority areas, is an essential part of a nation’s overall strategy for conservation and sustainable use of it’s biodiversity. During the 1990's, South Australia, with funding under the Natural Heritage Trust (and the former federal `Ocean Rescue 2000' initiative), has been developing a bioregional planning framework to assist with the establishment of a National Representative System of Marine Protected Areas (NRSMPA), and also, as a strategic tool for the integrated management and conservation of it's coastal and marine environments. Bioregional classification of South Australia's coastal and marine environments is an important initial step in achieving this goal. To this end, a biophysical classification of the range of coastal and marine environments in South Australia can be used to assist in the identification of ecologically or biogeographically the 'ecological representative areas and representativeness' of the existing system of MPAs. The definition of natural units for management not only facilitates planning and integrated ecosystem management, but also assist local managers and the community in such areas, in understanding the natural characteristics, features, limitations, and complexities of their local marine environments. The process of bioregionalisation classifies similar regions/habitats together at a range of spatial scales, within relatively homogenous, but distinctive, ecological units in terms of their natural biological and physical characteristics. To this end, the definition of such regions not only enable a systematic approach to planning and integrated management, but also, inventory, monitoring and audit of the marine environment and its resources. For marine resources (ie. fisheries, aquaculture, mining), where spatial distributions and dynamics are linked to ecological and physical processes and natural patterns of biodiversity, biogeographic regions provide an ecological framework for management which acknowledges the inherent natural variability and characteristics of marine ecosystems. The current strategy for bioregional identification and classification in South Australia is a systematic, hierarchically scaled one, with a focus on the conservation of biodiversity in the context of ecosystem structure and function. This hierarchical structure of biodiversity is intrinsically linked to the level of functional diversity or ecological processes and attributes. The aim is to identify a set of natural environmental units defined by biophysical parameters. In South Australia, the definition of the bioregional framework has largely been undertaken by the South Australian Research and Development Institute, in collaboration with State and Commonwealth agencies. This has been achieved largely through the undertaking of a comprehensive program of marine habitat and biodiversity mapping (ie. linking spatial environmental and biological data) to define the biogeographical regions of South Australia, and also, identify priority areas for marine conservation, based on regional patterns of diversity. The approach to bioregionalisation in South Australia uses the nested, hierarchical concept of ecosystems to develop a five level biophysical classification at the level of : 1 Pelagic Provinces (100,000s of km2, gigascale), which provides a broad scale strategic framework for the integrated management of pelagic resources; suitable for integrated pelagic fisheries management and integrated management of pelagic resources, global reporting, auditing; iii INTRODUCTION – PART TWO 2 Demersal Provinces (10,000s of km2, macroscale), which provides a broad scale strategic framework for the integrated management of demersal resources; suitable for integrated demersal fisheries management and integrated management of demersal resources, global reporting, auditing; 3 Biophysical Regions or `Bioregions` (1,000s of km2, mesoscale), which provides a national strategic framework for marine planning and ecological sustainable management of coastal resources; suitable for national biodiversity and conservation planning and priority-setting, pelagic fisheries management, reporting, auditing (eg. national State of the Environment Report); 4 Biophysical Units or `Biounits’ (100s of km2, microscale), which provides a regional strategic framework for marine planning and ecological sustainable management of coastal resources; identifies functional ecosystem-level management units (eg. rocky shores, dune barrier systems, archipelagos, shoals or reef systems, coastal peninsula, etc.); suitable for integrated multiple-use management and MPA declaration, regional biodiversity and conservation planning and priority-setting, fisheries management, reporting, auditing, monitoring, impact assessment; 5 and the level of habitats (1-10s of km2, picascale) , which provides information to address tactical site management issues at the habitat level (eg. bay, estuary, reefs, seagrass meadows); suitable for nature reserves, fishing closures, monitoring, impact assessment. The marine bioregionalisation at the bioregion and biounit incorporated and acknowledged the existing geomorphological classification of the coastal habitats of South Australia by Short et al. (1986), which utilised principally physical coastal landform and descriptors, such as wave environment, geology, coastal landform and coastal orientation. The results of this preliminary regionalisation were further refined and validated through ongoing systematic field surveys, knowledge of oceanographic processes, and also, more recently, under the national, Interim Marine and Coastal Regionalisation of Australia (IMCRA) project during 1995-1996. Provinces were defined on the basis of major oceanographic current systems for the pelagic regionalisation, and biogeographic patterns in the marine fish fauna for the demersal classification (CSIRO 1997, IMCRA 1997). In contrast, marine bioregions were defined on the basis of a range of physical descriptors, such as climate, oceanography (ie. temperature, salinity, tides, wave energy, upwellings), geology and coastal geomorphology, estuaries and also, major biogeographic patterns in the marine biota (particularly the sessile fauna and flora, such as mangroves, seagrass, macroalgae). Smaller-scale biounits were defined primarily on the basis of coastal physiography, topography and major marine physical habitat or seascape features (eg. shoal systems, archipelagos, coastal dune barrier systems, etc.) and habitat distributions. In the development of a scaled, hierarchical bioregional planning framework for South Australia, a total of 1 pelagic province, 1 demersal province (and 2 biotones), 8 bioregions, and 35 biounits have been identified (see Table 1.2). In South Australia, a preliminary bioregionalisation or classification of coastal habitats and ecosystems adopted an `expert panel' or `delphic' approach, utilising existing `qualitative' biophysical/ biogeographical information and the best technical judgements of local experts. This involved the formation of a specialist, SA Marine Protected Area Technical Working Group and the hosting of a technical workshop on the biophysical classification of South Australian marine and coastal environments in November 1991. iv INTRODUCTION – PART TWO Table 1.2: A nested hierarchical bioregional planning framework for South Australia’s coastal and marine ecosystems. PELAGIC PROVINCE Gigascale (100,000s km2) DEMERSAL PROVINCE/BIOTONES Macroscale (10,000s km2) BIOREGION BIOUNIT Mesoscale (1,000s km2) Microscale (100s km2) Eucla (EUC) Southern Pelagic Province (SPP) Great Australian Bight Biotone (GABB) Murat (MUR) Gulfs Province (GulfP) Eyre (EYR) Spencer Gulf (SGF) Northern Spencer Gulf (NSG) Gulf St Vincent (SVG) West Bassian Biotone (WbassB) Coorong (COR) Otway (OTW) Nullarbor (NUL) Wahgunyah (WAH) Fowlers (FOW) Nuyts (NUY) Streaky (STK) Yanerbie (YAN) Newland (NEW) Flinders (FLI) Sheringa (SHR) Douglas (DGL) Whidbey (WHD) Jussieu (JUS) Pondalowie (PON) Gambier (GAM) Gantheaume (GAN) Dutton (DUT) Franklin (FRK) Tiparra (TIP) Wardang (WAR) Yonga (YON) Winninowie (WIN) Sturt (STU) Investigator (INV) Orontes (ORO) Clinton (CLN) Yankalilla (YNK) Encounter (ENC) Sprigg (SPR) Backstairs (BCK) Nepean (NEP) Cassini (CAS) Coorong (COR) Canunda (CAN) Nene (NEN) Piccaninnie (PIC) v INTRODUCTION – PART TWO In several states, including South Australia, biogeographic or regional ecosystem classifications have involved utilising analytical multivariate procedures to classify patterns in nearshore ecosystem diversity (eg. Ortiz & Burchmore 1992, Edgar et al. 1995, LCC/DCNR 1995, Stevens 1995, Edyvane & Baker 1995, 1996). To-date, a total of 58 bioregions have been identified for the nearshore marine environments of Australia, on the basis of a wide range of physical and biological descriptors, such as climate, oceanography (water temperature, wave energy), tidal range, coastal geomorphology, biology (habitats, marine mammals, endemic species) (see Figure 1.1). For Australia, the challenge remains the critical integration of the existing terrestrial regionalisation (ie. Interim Biogeographic Regionalisation of Australia), with the marine regionalisation (ie. IMCRA), and also, the integration of inshore and offshore waters. 1.4 IMCRA - A National Template for Marine Biodiversity and Ecosystem Management The approach to bioregionalisation used in South Australia has formed part of an integrated coordinated State and Commonwealth effort a to develop an `Interim Marine and Coastal Regionalisation of Australia' (IMCRA), to assist in the development of a representative system of Marine Protected Areas (Muldoon 1995, IMCRA 1997). The IMCRA classification is principally a `delphic’ approach to biophysical regionalisation. In South Australia, this qualitative approach utilised the expertise of marine and coastal biological and physical researchers, results from ongoing field surveys and also, existing descriptive, spatially referenced biophysical coastal and marine data sets and maps. TC KIM SEB MIN CAR WEI TS RBN WWG BVD NWS KS CAN EMB PIO AW CAB SWG CYP WEL GBR WTC SBR LMC PIN SB ZUY MUR ABR SG PC EUC MOR NSG MAC SVG EYR CV COR WSC DO OK CBS Interim Marine and Coastal Regionalisation for Australia (IMCRA) Version 3.0 DAV GER ULL HOW LN Figure 1.1: MCM SC WF FRT BRU The mesoscale marine ecosystems of Australia as defined under the Interim Marine and Coastal Regionalisation of Australia (IMCRA) project (IMCRA 1997). vi INTRODUCTION – PART TWO 1.5 `Province’ or Large Marine Ecosystem Regionalisation Pelagic Regionalisation The `Interim Marine and Coastal Regionalisation of Australia’ (IMCRA 1997) classification defines one gigascale, pelagic province for South Australian waters: the Southern Pelagic Province (SPP). The core area of this province largely encompasses the Flindersian cool temperate marine biota. Southern Pelagic Province (SPP) • − Great Australian Bight Biotone (GABB) • − • − Location: Great Australian Bight from Israelite Bay (WA) to Point Brown (SA). • − Remarks: Weak biotone dominated by species from the South Western Province (SWP) in WA, with a few elements of the Gulf Province (GulfP) in SA. A major disjunction exits near the Recherche Archipelago corresponding to the western limits of a suite of wide-ranging species from the Central Eastern Province (CEP) and Tasmanian Province (TasP), and the eastern limits of the South Western Province. The biotone is also traversed by a large suite of wide-ranging, western, warm temperate species that extend along the southern Australian coast to the Gulf Provinces, Bassian Province (BassP) and the South Eastern Biotone (SEB), and a suite of ubiquitous temperate Australian species that originate in the Central Eastern Province and Biotone. (CEP and CEB). • − Mesoscale Regions: Includes Eucla and Murat regions. Area: 482,000 km2 • − Location: Extending from near Albany (WA) in the west, along the southern coast, to Lakes Entrance (Victoria) in the east and enclosing Bass Strait and the Tasmanian waters. • − Remarks: Largely comprised of Flindersian cool temperate species. The endpoint disjunctions also represent southern limits for warm temperate species in the Eastern and Western Pelagic Biotones (WPB and EPB). Intraprovincial disjunctions occur at Esperance and east of Point Dempster near the western edge of the Baxter Cliffs. In the east, disjunctions occur just east of Kangaroo Island and at Wilsons Promontory Demersal Regionalisation The `Interim Marine and Coastal Regionalisation of Australia’ (IMCRA 1997) classification defines one macroscale, demersal province for South Australian waters: the Gulfs Province (GulfP), and two biotones: the Great Australian Bight Biotone (GABB) and the West Bassian Biotone (WBassB). Biotones are the zones of transition between core provinces. The provinces and biotones are based on a classification of demersal fish species diversity and richness. Area: 200,000 km2 Gulfs Province (GulfP) • − Area: 35,379 km2 • − Location: Comprising the Gulfs of Spencer and St Vincent and enclosing Kangaroo Island. Extends out to the shelf break with a western boundary at Point Brown and an eastern edge at Cape Jervis. • − Remarks: A weak but unique province with a small endemic element and subtropical relict species. It has a strong disjunction near its northern boundary and acts as a major biotone for cool temperate species (TasP and BassP) and for a large suite of species from the South Western Province (SWP). The hypersaline and subtropical temperature conditions in the Gulfs are unique within temperate Australia and probably enable this region to act as a refugia for warmer water species. Once again, the unique relict nature of the region makes it worthy of recognition from a conservation standpoint (IMCRA 1997). vii INTRODUCTION – PART TWO • − Mesoscale Regions: Includes Eyre, Northern Spencer Spencer Gulf and St Vincent regions. Gulf, West Bassian Biotone (WBassB) • − Area: 89,751 km2 • − Location: Extends east from the South Australian Gulfs Province (GulfP), pentrating past King Island to a southern limit at the north-western tip of Tasmania and a northern limit slightly north of Apollo Bay (Victoria). • − Remarks: Zone of faunal overlap of elements derived mainly from the Tasmanian Province (TasP) and Bassian Province (BassP) to the east, as well as a small suite of extralimital species from the Central Eastern Province (CEP). Also contains elements from the South Western Province (SWP) and Gulfs Provinces (GulfP). • − Mesoscale Regions: Includes Otway and Coorong regions. 1.6 `Bioregion’ Regionalisation or Ecosystem-Level A total of 8 distinct inshore marine biogeographical regions (or “bioregions”) have been identified for South Australia (Figure 1.2). The seaward margin of the mesoscale bioregions is the edge of the continental shelf, defined as the 200 metre isobath. These bioregions include from the west: Eucla (Israelite Bay, Western Australia - Cape Adieu, South Australia), Murat (Cape Adieu - Point Labatt), Eyre (Point Labatt - Peake Bay, Cape Borda - West Cape), Northern Spencer Gulf (Point Riley - Port Augusta - Shoalwater Point), Spencer Gulf (Peake Bay - West Cape, Point Riley Shoalwater Point), St Vincent Gulf (Cape Borda West Cape, Cape Jervis - Cape Willoughby), Coorong (Cape Jaffa - Cape Borda) and OtwayKing (Cape Jaffa - Cape Otway, Victoria - King Island, Tasmania) (see Table 1.3). gradients with extensive intertidal, and supratidal areas (see Table 1.3). The biota is characterised by extensive areas of coastal saltmarshes, mangroves (dominated by the Grey Mangrove, Avicennia marina), and subtidal seagrass meadows. Northern Spencer Gulf is characterised by a unique tropical element in the fauna and flora. Together the bioregions of the gulfs are home to 7,950 km2 of seagrass or 82% of the total area of seagrass recorded in South Australia. The most extensive seagrass meadows (dominated by Posidonia species), occur in the clear, shallow, sheltered gulf waters of Northern Spencer Gulf (4,136 km2), with smaller meadows occurring in Spencer Gulf (5,520 km2) and Gulf St Vincent (2,440 km2). In contrast, the oceanic bioregions are dominated by extensive rocky coasts and sandy shores. The oceanic bioregions are characterised by exposed rocky coasts and headlands (comprising Precambrian metasediment cliffs, Pleistocene dune rock cliffs), interspersed with Holocene dune barrier beaches and lagoon deposits in sheltered areas, microtidal tidal ranges, and shallow to moderate offshore gradients (see Table 1.3). The Eucla, Murat and Eyre are characterised by a predominance of rocky coasts, while the Coorong and Otway coasts are typically small barrier coasts. The Eyre, Coorong and Otway Bioregions experience moderate to high energy wave and swell conditions (experiencing some of the highest wave energies in the State), and are dominated by extensive reefal habitats, sandy bottom substrates and transgressive dune systems. The Eyre and Otway regions are also distinguished by the presence of localised, seasonal, nutrient-rich coldwater upwellings. In contrast, the Murat Bioregion comprises a series of extensive, shallow water embayments, protected by the Nuyts Archipelago, and dominated by extensive seagrass meadows and mangroves. A full description of the bioregions of South Australia is provided in IMCRA (1997) (see Appendix 1). The marine bioregions of South Australia vary from the oceanic bioregions of Eucla (EUC), Murat (MUR), Eyre (EYR), Coorong (COR) and Otway (OTW), to the gulf bioregions of Spencer Gulf (SGF), Northern Spencer Gulf (NSG) and St Vincent Gulf (SVG). The gulf bioregions are semiconfined or confined inverse estuaries, characterised by tidal plain coasts and landforms, micro-mesotidal tidal ranges, and shallow offshore viii INTRODUCTION – PART TWO Table 1.3: A summary of the IMCRA bioregions of South Australia Bioregion Total Area of Bioregion (ha) SA Area of Bioregion (ha) Major Inshore Habitats Major Physical /Biological Descriptors Eucla (EUC) 11,111,514 189,073 Sand (391 km2, 88.5%) Reef (51 km2, 11.5) rocky coast; dominated by the Nullarbor Cliffs and Eucla Basin; warm water Leeuwin Current; microtidal; warm temperate biota, moderate biodiversity Murat (MUR) 3,558,736 133,703 Seagrass (880 km2, 61.3%) Sand (309 km2, 21.5%) Reef (246 km2, 17.2%) rocky crenulate coast, embayments; Nuyts Archipelago, seamounts; microtidal; warm temperate biota, extensive seagrass meadows, mangroves Eyre (EYR) 7,216,500 1,425,723 Sand (1543 km2, 56.2%) Reef (674 km2, 24.6%) Seagrass (527 km2, 19.2%) rocky coast, offshore islands, seamounts; localised upwellings; microtidal; cool temperate biota, high biodiversity, productivity, importance for marine mammals, seabirds Spencer Gulf (SGF) 1,187,451 1,199,299 Seagrass (1377 km2, 41.2%) Sand (1351 km2, 40.5%) Reef (611 km2, 18.3%) tidal plain coast, embayments; shallow offshore gradient; semiconfined, inverse estuary; micro-mesotidal; cool temperate biota, high endemism, extensive seagrass meadows 444,803 478,824 Seagrass (4136 km2, 58.1%) Sand (2487km2, 34.9%) Reef (493 km2, 6.9%) tidal plain coast; shallow offshore gradient; confined, inverse estuary; mesotidal; subtropical-tropical element in biota, high endemism; extensive seagrass meadows, mangroves St Vincent Gulf (SVG) 1,283,817 1,441,971 Seagrass (2438 km2, 59.6%) Sand (1057 km2, 25.9%) Reef (595 km2, 14.5%) tidal plain coast; shallow offshore gradient; confined, inverse estuary; micro-mesotidal; cool temperate biota, high endemism, extensive seagrass meadows, mangroves Coorong (COR) 3,197,170 178,575 Reef (991 km2, 48.2%) Sand (812 km2, 39.5%) Seagrass (255 km2, 12.4%) large barrier coast; Coorong Lagoon and Murray River; gradational nearshore-offshore gradient; cool temperate biota, moderate biodiversity Otway (OTW) 3,733,126 120,639 Reef (582 km2, 87.4%) Sand (84 km2, 12.6%) Seagrass (0.5 km2, 0.1%) small barrier coast; localised upwellings; cold temperate biota, high biodiversity, productivity 32,000,000 5,167,807 6,094,800 Northern Spencer Gulf (NSG) Total ix INTRODUCTION – PART TWO EUCLA NORTHERN SPENCER GULF MURAT EYRE SPENCER GULF GULF ST VINCENT COORONG OTWAY Figure 1.2: Marine Bioregions of South Australia 1.7 `Biounit’ or Habitat-Level Regionalisation A total of 35 biounits have been identified along the inshore coastal waters of South Australia (see Figure 1.3, Table 1.4). These include a total of 30 coastal biounits and 5 offshore biounits, which comprise offshore islands and waters without adjacent mainland coasts (ie. Nuyts, Flinders, Investigator, Gambier, Sprigg). The biounits were delineated on the basis of major coastal physiographic features and the representation and distribution of major marine habitats. The seaward boundary of the gulfs biounits was defined using the 30 m bathymetric contour, on the basis that major habitat changes are known to occur in deeper waters, beyond the photic zone. Similarly, the seaward boundary of the oceanic biounits was defined using the 50 m depth contour, on the basis that the photic zone is known to occur deeper in the clearer oceanic waters of South Australia. INTRODUCTION – PART TWO Table 1.4: Summary of the marine and coastal biounits for the inshore waters of South Australia. Bioregion/ Biounit Inshore/Offshore Biounit Total Area (ha) SA Waters (ha)1 Major Feature; Physical/Biological Descriptors; Inshore Habitats 1 EUCLA Nullarbor Inshore 842,642 112,959 Nullarbor Cliffs; high energy, limestone cliffs, reefs; sand (11,836 ha, 75.2%) and reef habitats (3,908 ha, 24.8%) 2 Wahgunyah Inshore 195,381 76,114 Wahgunyah CR; high energy, extensive dune transgressions; mostly sand (27,971 ha, 94.2%) and some reef habitats (1,722 ha, 5.8%) 1,038,023 189,073 Subtotal 3 MURAT Fowlers Inshore 146,486 133,702 Fowlers Bay; high energy, rocky limestone coast; mostly reefs (21,666 ha, 81.9%), some sand (3,134 ha, 11.9%) and seagrass habitats (1,639 ha, 6.2%) 4 Nuyts Offshore 283,165 250,448 Nuyts Archipelago; offshore islands; mostly reefs (2,483 ha, 91.6%), some seagrass (144 ha, 5.3%) and sand habitats (84 ha, 3.1%) 5 Streaky Inshore 190,949 190,950 Streaky Bay; sheltered embayments, rocky headlands; mangroves, large areas of seagrass (86,163 ha, 77.6%), some sand (22,466 ha, 20.2%), and reef habitats (2,343 ha, 2.1%) 620,600 575,101 Subtotal 1 SA waters refers to territorial sea, land and inland waters. xi INTRODUCTION – PART TWO Table 1.4: Summary of the marine and coastal biounits for the inshore waters of South Australia (cont….) Bioregion/ Biounit Inshore/Offshore Biounit Total Area (ha) 6 EYRE Yanerbie Inshore 82,854 80,569 Yanerbie Sandpatch; high energy, rocky limestone coastline; sand (9,573 ha, 43.6%), seagrass (6,602 ha, 30.0%) and reef habitats (5,802 ha, 26.4%) 7 Newland Inshore 45,238 39,714 Newland Barrier; high energy, extensive dune barrier system; mostly sand (4,318 ha, 57.2%) and reef (3,231 ha, 42.8%) habitats 8 Flinders Offshore 125,957 64,660 Flinders Isles; high energy, offshore islands, seamounts; mostly reef habitats (4,194 ha) 9 Sheringa Inshore 51,156 42,156 Sheringa Lagoon; high energy, large barrier dune systems; mostly reef habitats (4,605 ha, 94.1%), some sand (224 ha, 4.6%) and seagrass habitats (65 ha, 1.3%) 10 Douglas Inshore 67,645 66,729 Port Douglas; moderate to low energy, large sheltered embayments, rocky headlands; sand (18,619 ha, 50.1%), seagrass (8,567 ha, 23.1%), and reef habitats (9,965 ha, 26.8%) 11 Whidbey Inshore 132,689 107,839 Whidbey Isles; high energy, rocky coast, offshore islands, seamounts, localised upwellings; most sand (38, 489 ha, 88.1%) and some reef habitat (5,221 ha, 11.9%) 12 Jussieu Inshore 240,439 240,439 Jussieu Peninsula; large sheltered embayments, rocky headlands, offshore islands; sand (65,921 ha, 42.9%), seagrass (56,956 ha, 37.1%) and reef habitats (30,649 ha, 20.0%) 13 Pondalowie Inshore 22,130 22,131 Pondalowie Bay; high energy, rocky coastline, upwellings; sand (15,077 ha, 83.9%), reef (2,862 ha, 15.9%) and some seagrass habitats (25 ha, 0.1%) 14 Gantheume Inshore 167,363 111,066 Cape Gantheaume; high energy, rocky coast; mostly reef (31,857 ha, 60.5%), sand (19,521 ha, 37.1%) and some seagrass habitat (1,263 ha, 2.4%) 935,471 775,302 Subtotal 1 SA Waters (ha)1 Major Feature; Physical/Biological Descriptors; Inshore Habitats SA waters refers to territorial sea, land and inland waters. xii INTRODUCTION – PART TWO Table 1.4: Summary of the marine and coastal biounits for the inshore waters of South Australia (cont….) Bioregion/ Biounit Inshore/Offshore Biounit Total Area (ha) SPENCER 15 Dutton Inshore 255,443 255,443 Dutton Bay; sheltered rocky coast; mostly seagrass (25,706 ha, 98.5%), some reef (197 ha, 0.8%) and sand habitats (190 ha, 0.7%) 16 Franklin Inshore 198,588 198,588 Franklin Harbour; large sheltered embayment; mangroves, sand (87,258 ha, 61.4%), reef (39,361 ha, 27.7%) and seagrass habitats (15,447 ha, 10.9%) 17 Tiparra Inshore 243,228 243,228 Tiparra Reef; moderately-high energy, extensive shallow seagrass-reef shoal system; seagrass (83,912 ha, 81.3%), reef (4,491 ha, 4.4%) and sand habitats (14,782 ha, 14.3%) 18 Wardang Inshore 285,583 285,583 Wardang Island; moderate energy, large embayment, rocky headlands; sand (65,722 ha, 44.7%), reef (54, 739 ha, 37.3%), seagrass habitats (26, 458 ha, 18.0%) 19 Gambier Offshore 536,544 536,544 Deeper water habitats of the Spencer Gulf; Gambier Isles; sand (15,160 ha, 68.4%), seagrass (5,123 ha, 23.1%) and some reef habitat (1,865 ha, 8.4%) 1,519,388 1,519,388 Subtotal SA Waters (ha)1 Major Feature; Physical/Biological Descriptors; Inshore Habitats NORTHERN SPENCER GULF 20 Yonga Inshore 55,267 55,267 Yonga Shoal; sheltered gulf waters, shoals; large areas of seagrass (248,596 ha, 59.1%) and sand (161,715 ha, 38.5%), some reef habitat (10,054 ha, 2.4%) 21 Winninowie Inshore 423,557 423,557 Winninowie CP; very sheltered gulf waters; mostly sand (37,727 ha, 69.6%) and seagrass habitats (16,484 ha, 30.4%) 478,824 478,824 Subtotal 1 SA waters refers to territorial sea, land and inland waters. xiii INTRODUCTION – PART TWO Table 1.4: Summary of the marine and coastal biounits for the inshore waters of South Australia (cont….) Inshore/Offshore Biounit Total Area (ha) GULF ST VINCENT 22 Sturt Inshore 183,058 183,058 Sturt Bay; moderate-high energy, large bays, rocky headlands; seagrass (25,611 ha, 75.0%), reefs (5,088 ha, 14.9%) and sand habitats (3,465 ha, 10.1%) 23 Investigator Inshore 280,063 280,063 Investigator Strait; moderate-high deepwater habitats; sand (490 ha) 24 Orontes Inshore 183,762 183,762 Orontes Bank; extensive shallow seagrass-reef shoal system; seagrass (51,713 ha, 56.5%), reef (33,745 ha, 36.9%) and sand habitats (6,081 ha, 6.6%) 25 Clinton Inshore 249,136 249,136 Clinton CR; sheltered gulf waters; large areas of mangroves, seagrasses (132, 576 ha, 84.4%), sand (21,173 ha, 13.5%) and some reef habitat (3,280 ha, 2.1%) 26 Yankalilla Inshore 51,562 51,562 Yankalilla Bay; moderate energy, bays, rocky headlands; sand (15,845 ha, 62.2%) and seagrass (7,645 ha, 30.0%), some reefs (1,966 ha, 7.7%) 27 Encounter Inshore 39,389 39,389 Encounter Bay; high energy, rocky coast, bays; mostly reef (5,452 ha, 57.8%), sand (3,482 ha, 36.9%) and some seagrass habitat (505 ha, 5.4%) 28 Sprigg Offshore 160,548 160,548 29 Backstairs Offshore 35,911 35,322 Backstairs Passage; strong tidal currents, deepwater habitats; seagrass (668 km, 52.1%), reef (527 km, 41.1%), and some sand habitats (87 km, 6.8%) 30 Nepean Inshore 102,304 102,232 Nepean Bay; sheltered embayments; mostly seagrass (23,229 ha, 49.6%), sand (21,523 ha, 45.9%), and some reef habitat (2,124 ha, 4.5%) 31 Cassini Inshore 45,760 45,760 Cape Cassini; moderate energy, rocky coast; mostly sand (12,943 ha, 81.6), reef (2,263 ha, 14.3%) and some seagrass habitat (662 ha, 4.2%) 1,331,491 1,330,950 Bioregion/ Biounit Subtotal 1 SA Waters (ha)1 Major Feature; Physical/Biological Descriptors; Inshore Habitats Deeper water habitats of Gulf St Vincent SA waters refers to territorial sea, land and inland waters. xiv INTRODUCTION – PART TWO Table 1.4: Summary of the marine and coastal biounits for the inshore waters of South Australia (cont….) Bioregion/ Biounit COORONG 32 Coorong Inshore/Offshore Biounit Inshore Subtotal Total Area (ha) SA Waters (ha)1 1,290,715 178,575 1,290,715 178,575 Major Feature; Physical/Biological Descriptors; Inshore Habitats Coorong Lagoon; high energy, extensive lagoon system, dune barrier; mostly sand (75,497 ha, 44.2%), reef (70,376 ha, 41.2%) and some seagrass habitat (25,062 ha, 14.7%) OTWAY 33 Canunda Inshore 233,897 84,833 Canunda NP; high energy, rocky coast, dune barriers, offshore reefs; mostly reef (50,552 ha, 90.5%), some sand (5,333 ha, 9.5%) and sparse seagrass (2 ha, <0.1) 34 Nene Inshore 32,543 19,061 Nene Valley CP; high energy, rocky coast, offshore reefs; mostly reef habitat (9,981 ha, 97.7%), and some sand habitat (234 ha, 2.3%) 35 Piccaninnie Inshore 44,923 16,746 Piccaninnie Ponds CP; rocky coast, offshore reefs; mostly sand habitats (2,798 ha, 79.6%), some reefs (675 ha, 19.2%) and sparse seagrass (44 ha, 1.3%) 311,363 120,639 Subtotal 1 SA waters refers to territorial sea, land and inland waters. xv INTRODUCTION – PART TWO Some of the marine biounits identified for South Australia encompass solely state jurisdictional waters (eg. biounits within the gulfs). Other biounits encompass both SA and Commonwealth territorial seas. As expected, the representation and range of marine ecosystems varies considerably between the biounits (see Table 1.4), from the reefseagrass shoal systems of Orontes and Tiparra, to the offshore islands and seamounts of Whidbey and Flinders, to the large seagrass-dominated embayments of Jussieu and Streaky, to the mangrove-seagrass inverse estuaries of Clinton, Winninowie, and Yonga. The Yonga biounit alone represents over 25% of the total seagrass recorded in South Australia. Other significant ecosystems include the strong tidal current ecosystem of Backstairs, the rocky cliff habitats of Nullarbor and the extensive nearshore reefs systems of Canunda and Nene. WAH NUL STK FOW NUY WIN YAN NEW YON FRK SHR FLI DUT DGL TIP JUS CLN WAR GAM ORO WHD STU SPR YNK INV NEP GAN ENC BCK COR CAN NEN PIC Figure 1.3 Marine Bioregions and Biounits of South Australia 1.8 Criteria for Identifying Conservation Significance Areas of The present approach to identifying areas of high marine conservation value in South Australia, utilises a analytic approach, which applies formal criteria, based on a range of ecological, social and economic criteria to identify areas of high conservation value (for establishment as potential Marine Protected Areas). Application of these criteria acknowledges: − previous recommendations of the SA Marine Protected Areas Technical Working Group (see Edyvane and Baker 1995) − areas of recognised State significance (eg. National Parks, Conservation Parks, − − Conservation Reserves, sites listed on the SA Heritage List, historic shipwrecks, geological monuments) areas of recognised national significance (eg. Wetlands of National Importance, sites listed on the Register of the National Estate) areas of recognised international significance (eg. RAMSAR listed sites) The following is a list of formal criteria endorsed by IUCN (Kelleher & Kenchington 1991) and nationally (Environment Australia 1998), which can used in the identification of areas of conservation significance for potential selection as part of a nationally representative system of MPA’s: xvi INTRODUCTION – PART TWO • − Naturalness: this is the extent to which the area has been protected from, or has not been subject to human-induced change (eg. wilderness areas). • − Biogeographic Importance: an area which possesses either rare biogeographic qualities or is representative of a biogeographic "type" or types; contains unique or unusual geological features. • − Ecological Importance: an area which contributes to maintenance of essential ecological processes or life-support systems eg. source for larvae for downstream areas; integrity - the degree to which the area either by itself or in association with other protected areas, encompasses a completer ecosystem; contains a variety of habitats; contains habitat for rare or endangered species; contains nursery or juvenile areas (eg. seagrass, mangroves); contains feeding, breeding or rest areas; contains rare or unique habitat for species; preserves genetic diversity, ie. is diverse or abundant in species terms. • − Economic Importance: an area of existing or potential contribution to economic value by virtue of its protection eg. protection of an area for recreation, subsistence, use by traditional inhabitants, appreciation by tourists and others or as a refuge nursery area or source of supply for economically important species (eg. fish nursery/breeding/feeding areas). • − Social Importance: an area of existing or potential value to the local, national or international communities because of its heritage, historical, cultural, traditional aesthetic, educational or recreational qualities. • − Scientific Importance an area of value for research and monitoring (eg. research sites in which to demonstrate ecological processes or monitor global change) • − International or National Significance: an area which is or has the potential to be listed on the World or a national Heritage List or declared as a Biosphere Reserve or included on a list of areas of international or national importance or is the subject of an international or national conservation agreement. • − Practicality/feasibility: an area with a degree of insulation from external destructive influences; social and political acceptability, degree of community support; accessibility for education, tourism, recreation; compatibility with existing uses, particularly by locals; ease of management, compatibility with existing management regimes (eg. adjacent to terrestrial parks). Areas adjacent to terrestrial parks benefit from their proximity to terrestrial parks because there are likely to be less environmentally damaging threats to the marine environment from the controlled and protected terrestrial sources within the park. As such, terrestrial parks act as buffer zones to MPAs. By examining a range of these IUCN attributes it is possible to identify areas of high conservation values in South Australia, based on a range of natural, social, economic and cultural criteria. Areas in South Australia of where these IUCN attributes apply are based on application of the formal criteria, and are outlined later in this report for each coastal region and recognised biounit. xvii INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) Region Code & Number Data Attribute Description COR SA / 43 COORONG Climate: Cool temperate, meso-thermal climate with cool, wet winters and warm, dry summers. Oceanography: Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 14oC in winter to 19oC in summer. Offshore gradient decreases from steep to flat resulting in a gradational coastline, from high deepwater wave energies at Cape Jaffa to low energies near the Murray Mouth. Tidal range, microtidal, ~ 0.8 to 1.2 metre range. Coastal Geology and Geomorphology Large barrier coast dominated by a gradational nearshore-offshore gradient and bio-clastic carbonate sediments. Coast comprising headlands and cliffs of Precambrian crystalline rock and metasediments and also, Pleistocene dune rock cliffs, headlands, shore platforms and reefs, interspersed with Holocene pocket beaches. Southern coast dominated by a large beach-dune barrier lagoon complex comprising the extensive Coorong lagoon and Holocene beach ridge plains of Lacepede Bay. Offshore gradient traversed by the extensive Murray Canyons which extend offshore from the Murray River. Biota: Marine flora and fauna typical of transitional warm to cold temperate waters (ie. Flindersian Province). Intertidal and sublittoral fringe dominated by the brown alga, Cystophora intermedia. On rocky limestone shores, subtidal macroalgal communities are dominated by red algae assemblages (particularly Osmundaria and species of Plocamium), species of Caulerpa (particularly C.flexilis) and Cystophora (such as C.subfarcinata, C.monoliformis and C.platylobium) and Ecklonia radiata. Granite boulder coasts are dominated by Scytothalia dorycarpa, Acrocarpia paniculata, Carpoglossum confluens, and Ecklonia radiata on exposed coasts and species of Cystophora in areas of moderate wave energies. Extensive seagrass meadows occur at Kingston (Lacepede Bay). Seagrass meadows dominated by Posidonia australis in shallow areas, and P.angustifolia. Lacepede Bay is the easterly limit of P.sinuosa. Plant species diversity is moderate to low. Coorong Lagoon supports one of the largest concentrations of waterbirds and migratory waders in Australia. Coastal wetlands of national importance in the region include the Coorong Lagoon (including Lake Alexandrina and Lake Albert), and the Tookayerta and Finniss River. Estuaries: Region dominated by the Murray River and extensive estuarine and ephemeral salt lakes of the Coorong Lagoon. xviii INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description EUC WA & SA / 37 EUCLA (SA) Climate: Semi-arid or `Mediterranean' climate, with hot, dry summers and cool, moist winters. Oceanography: Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 14oC in winter to 19oC in summer (increasing to 22oC in summer under the seasonal influence of the warm water Leeuwin Current). Open moderate to high wave energy, west-facing coastline. High wave swell environment, 2-4m. Tidal range, microtidal ~ 0.8 to 1.2 metre range. Coastal Geology & Geomorphology: Rocky cliff coastline, with a shallow offshore gradient, dominated by bio-clastic carbonate sediments. Coastal geology characterised by the sedimentary Eucla Basin and dominated by the Nullarbor Tertiary limestone cliffs, Pleistocene dune rock headlands and reefs, interspersed with Holocene beaches and dune barriers. Narrow intertidal rock platforms are present at the base of the cliffs in some places. Biota: Marine flora and fauna typical of transitional warm to cold temperate waters (ie. Flindersian Province). Intertidal and sublittoral fringe dominated by the brown alga, Cystophora intermedia. On the high energy limestone reefs, subtidal macro-algal communities are dominated by Scytothalia dorycarpa and Ecklonia radiata, with species of Cystophora (such as C.platylobium) as subdominants. Few seagrass communities along this high energy coast. Plant species diversity is moderate to low. Significant breeding and calving area of the Southern Right Whale (Eubalaena australis) and large number of breeding colonies of the Australian Sea Lion (Neophoca cinerea). Distinct tropical element in the fauna and flora of the region (ie. plankton, fish, echinoderms, hydroids), due to the warm water Leeuwin Current. Estuaries: No true rivers or estuaries in this region. xix INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description EYR SA / 39 EYRE Climate: Semi-arid or `Mediterranean' climate, with hot, dry summers and cool, moist winters. Oceanography: Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 14oC in winter to 19oC in summer (decreasing to 11-12oC under the influence of localised, cold nutrient-rich coastal upwellings). Moderate to high deepwater wave energy coastline. Tidal range, microtidal ~ 0.8 to 1.2 metre range. Coastal Geology & Geomorphology: Rocky coast with a shallow to moderate offshore gradient, dominated by bio-clastic carbonate sediments, comprising numerous headlands and sheltered, extensive shallow embayments, dominated by seagrasses. Coastal geology on exposed rocky coasts comprises Precambrian metasediment cliffs and also, Pleistocene dune rock cliffs, headlands and shore platforms, interspersed with Holocene dune barriers beaches and lagoon deposits in sheltered areas. Cainozoic colluvial and fluvial sediments. Numerous offshore islands and seamounts. Biota: Marine flora and fauna typical of transitional warm to cold temperate waters (ie. Flindersian Province). Intertidal and sublittoral fringe on rocky shores dominated by the brown alga, Cystophora intermedia. On rocky limestone shores, subtidal macro-algal communities are dominated by red algae assemblages (particularly Osmundaria and species of Plocamium), species of Caulerpa (ie. C.flexilis) and Cystophora (such as C.subfarcinata, C.monoliformis and C.platylobium) and Ecklonia radiata. In sheltered areas, subtidal seagrass communities dominated by Posidonia australis in shallow waters, and P.sinuosa, P. angustifolia, Amphibolus antarctica and A. griffithsii in deeper waters. Plant species diversity is high, particularly among the red algae. Marine fish fauna characterised by the presence of the SA endemic, Crested Threefin (Norfolkia cristata). Significant breeding colonies of the Australian Sea Lion (Neophoca cinerea) and New Zealand Fur Seal (Arctocephalos forsteri), particularly on the offshore islands. Coastal wetlands of national importance in the region include, Streaky Bay (Acraman Creek), Point Labatt, Baird Bay, Lake Newland, Lake Hamilton, Coffin Bay, Tod River, Tumby Bay, on the Eyre Peninsula and D’Estres Bay, Rocky River, Breakneck River, North West River, South West River on Kangaroo Island. Estuaries: No true rivers, but several intermittent streams (eg. Tod River, First Creek on Eyre Peninsula, and Stun’sail Bloom, Breckneck, Rocky, Wilson, Eleanor, Harriet, South West Rivers on southern Kangaroo Island) and coastal salt lakes (eg. Lake Newland, Lake Hamilton). xx INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description MUR SA / 38 MURAT Climate: Semi-arid or `Mediterranean' climate, with hot, dry summers and cool, moist winters. Oceanography: Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 14oC in winter to 19oC in summer (increasing to 22oC in summer under the seasonal influence of the warm water Leeuwin Current). Moderate to low wave energy coastline. Tidal range, microtidal ~ 0.8 to 1.2 metre range. Coastal Geology & Geomorphology: Rocky crenulate coastline, with a shallow offshore gradient, dominated by bio-clastic sediments, and comprising numerous shallow sheltered embayments, dominated by seagrasses. Coastal geology comprising headlands of Precambrian crystalline rock (usually with a dune rock capping), and Pleistocene dune rock cliffs, reefs and headlands, interspersed with Holocene beaches, dunes and estuarine deposits including intertidal and supratidal flats. Numerous offshore islands and seamounts. Biology: Marine flora and fauna typically warm temperate (ie. Flindersian). Extensive seagrass communities in embayments and lee of islands. On sandy shores, in sheltered areas, intertidal flats are dominated by the grey mangrove, Avicennia marina, the brown alga, Hormosira banksii, and the seagrasses, Heterozostera muelleri and Zostera tasmanica. Subtidal seagrass communities dominated by Posidonia australis in shallow waters, and P.sinuosa, P. angustifolia, Amphibolus antarctica and A. griffithsii in deeper waters. On rocky shores, exposed limestone coasts are dominated by Ecklonia radiata and Scytothalia dorycarpa. In calmer areas, macro-algal communities are dominated by Sargassum and Osmundaria on moderate coasts and Scaberia agardhii in low wave energy conditions. Granite boulder reefs are dominated by Scytothalia dorycarpa and species of Cystophora (such as C.monoliformis). Plant species diversity is moderate to low. Distinct tropical element in the fauna and flora of the region (ie. plankton, fish, echinoderms, hydroids), due to the Leeuwin Current. Coastal wetlands of national importance in the region include Davenport Creek (Tourville Bay). Estuaries: No true rivers, but a few intermittent streams and tidal mangrove creeks (eg. Davenport Creek). xxi INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description NSG SA / 40 NORTH SPENCER GULF Climate: Semi-arid or `Mediterranean' climate, with hot, dry summers and cool, moist winters. Oceanography: Confined inverse estuary, with minimal freshwater water input and higher salinities and temperatures in the upper reaches of the Gulf. Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 11-24°C at Point Lowly and 13-29°C at Port Augusta. Mean salinity increases from 42.0-44.8% at Point Lowly, to 43.2-48.6% at Port Augusta. Low wave energy coastline. Tidal range, microtidal to mesotidal 1.8 to 3.6 metre range. Tides are typified by a regular period of minimal tidal movement or `dodge tide'. Coastal Geology & Geomorphology: Tidal plain coast comprised of shallow offshore gradients, extensive intertidal and supratidal areas dominated by samphires, mangroves, and seagrasses. Coastal geology comprises Precambrian metasediment shore platforms, Holocene sandflats, beach ridges, recurved spits, and extensive intertidal and supratidal flats. Biota: Marine flora and fauna typical of transitional warm to cold temperate waters (ie. Flindersian Province), but with a distinct subtropical element, characterised by the presence of tropical species such as the brown alga, Sargassum decurrens and Hormophysa triquetra. In sheltered areas, intertidal flats are dominated by extensive areas of the grey mangrove, Avicennia marina, together with the brown alga, Hormosira banksii, and the seagrasses, Heterozostera muelleri and Zostera tasmanica. Subtidal areas characterised by extensive sandy substrates and seagrass meadows, dominated by Posidonia australis in shallow areas, P.sinuosa, P.angustifolia and Amphibolus antarctica in deeper waters, and small shore fringing macro-algal communities. Limited rocky areas by macro-algal communities dominated by Scaberia agardhii, Lobophora, Cystophora botryoides and C.expansa and Caulocystis. Plant species diversity very low. Sparse to no plant cover in deeper waters (>17 metres), animal dominated. Coastal wetlands of national importance in the region include the upper Spencer Gulf mangroves from Port Augusta, south to Whyalla and Jarrold’s Point, Fisherman’s Bay and Port Broughton. Estuaries: No true rivers, but many intermittent streams and tidal mangrove creeks (eg. Chinaman Creek, First-Seventh Creeks, Port Davis Creek, Fisherman Creek). xxii INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description OTW SA, VIC & TAS / 44 Climate: Oceanography: OTWAY Cool temperate, meso-thermal climate with cool, wet winters and warm, dry summers. Coastline typically high energy, with wave energy dependent on the orientation to prevailing swell direction and cross shelf width. The western region is typified by a high deepwater wave energy, attenuated by a steep offshore-nearshore gradient and offshore reefs which provide for moderate to low energy conditions. Waters are cold temperate and typified by localised, regular, seasonal, cold, nutrient-rich coastal upwellings in the west of the region. Mean sea surface temperatures vary from 14oC in winter to 18o C in summer (decreasing to 11-12o C under the influence of the upwellings). The far eastern region (ie. King Island area) is influenced during winter months by warm waters, making this region warmer than other Tasmanian waters at that time. Here also, summer water temperatures are cooler than elsewhere in the Bassian Province. Tidal range is microtidal (ie. ~ 0.8 to 1.2 metres range), through much of the area, however tidal ranges and velocities vary rapidly in the that part of the region forming the western entrance to Bass Strait. In the western region, two large unconfined aquifers (in the Gambier Limestone and Dilwyn Formation) discharge freshwater at the coast via beach springs and spring lakes. Narrow, dominantly south west facing, continental shelf, including the western entrance to Bass Strait. Small barrier coast dominated by a steeply sloping offshore gradient, dominated by bio-clastic carbonate sediments, and few coastal embayments. Coastal geology comprises headlands of Pliocene - Pleistocene volcanic outcrops, and also Pleistocene dune rock cliffs, shore platforms and offshore reefs (which provide coastal protection), Tertiary sediments and around King Island, Palaeozoic granite and associated sediments. Sandy beaches common in the western region (and around King Island), and also, within coastal embayments (ie. Rivoli Bay, Guichen Bay) which are characterised by Holocene beach ridge plains, beaches and dunes. Cliffed shorelines common elsewhere. Marine flora and fauna typically cold temperate (ie. Maugean element of the Flindersian Province). Intertidal and sublittoral fringe on wave-exposed coasts dominated by the bull kelp, Durvillea potatorum. Rocky subtidal macroalgal communities are dominated by Macrocystus angustifolia, Phyllospora comosa and other large brown fucoid algae. For many macro-algal communities, this region forms the westward limit of a number of key species. Extensive areas of seagrass occur in the limited sheltered embayments, with smaller areas in the lee of reefs. Subtidal seagrass meadows dominated by Posidonia australis in shallow areas, P.sinuosa, P.angustifolia and Amphibolus antarctica in deeper waters. Rivoli Bay is the easterly limit of P.coriacea and P.denhartogii. Port MacDonnell is the easterly limit of P.angustifolia. Plant species diversity is very high, particularly among the red algae. Fish and plant species richness both high compared to other South Australian, Victorian and Tasmanian regions. This is the only recorded area within Tasmanian waters where several species more typically associated with South Australia occur (for eg. the queen morwong Nemadactylus valenciennesi). Coastal wetlands of national importance in the region include Butchers and Salt Lakes, Ewens Ponds, Piccaninnie Ponds and the coastal lakes of Lake Robe, Eliza, George, and St Clair. No true rivers in the western region, but a few groundwater fed creeks (eg. Eight Mile Creek, Ellards Creek), and coastal salt lakes intermittently connected to the sea (eg. Lake George). Six moderate-sized barrier estuaries on King Island and numerous coastal lagoons. See also VE - Victorian estuaries. Coastal Geology & Geomorphology: Biology: Estuaries: xxiii INTRODUCTION – PART TWO Appendix 1: The IMCRA bioregions of South Australia (from IMCRA 1997) (cont….) Region Code & Number Data Attribute Description SVG SA / 42 ST VINCENT GULF Climate: Semi-arid or `Mediterranean' climate, with hot, dry summers and cool, moist winters. Oceanography: Confined inverse estuary, with higher salinities and temperatures in the upper reaches of the Gulf. Waters are transitional warm to cold temperate, with mean sea surface temperatures varying from 12°C in winter to 25.9°C in summer and mean salinities varying from 35.5-42.0%. Low to moderate wave energy coastline. Tidal range, microtidal to mesotidal ~ 1.2 to 3.3 metre range in the upper Gulf areas. Tides are typified by a regular period of minimal tidal movement or `dodge tide'. Coastal Geology & Geomorphology: Tidal plain coast with a shallow offshore gradient, extensive intertidal and supratidal areas, and few embayments. Coastal geology comprises headlands of Precambrian metasediment and Tertiary cliffs and Holocene beaches, sandflats, dunes, beach ridges, and estuarine deposits. Biota: Marine flora and fauna typically cool temperate (ie. Flindersian Province). In sheltered areas, extensive intertidal flats are dominated by the grey mangrove, Avicennia marina, the brown alga, Hormosira banksii, and the seagrasses, Heterozostera muelleri and Zostera tasmanica. Extensive subtidal seagrass communities occur down to 17 metres water depth (becoming sparsely vegetated at greater depths). Subtidal areas characterised by extensive seagrass meadows, dominated by Posidonia australis in shallow areas (and northern gulf), P.sinuosa, P.angustifolia and Amphibolus antarctica in deeper waters (and mid-gulf and sheltered parts of the lower gulf), and small shore fringing macro-algal communities. Seagrasses in the P.ostenfedii group form small communities along exposed parts of the lower gulf. Isolated reefs and rocky shore algal communities are dominated by Scaberia agardhii and species of Sargassum in sheltered areas, and Ecklonia radiata, Seirococcus axillaris and species of Cystophora in moderately exposed areas. Plant species diversity low. Distinct SA endemic and subtropical element in the fish fauna (ie. Vanacampus vercoi, Acentronura australe, Campichthys tryoni). Coastal wetlands of national importance in the region include Clinton, Barker Inlet estuary, Wills Creek, Davenport Creek, Port Gawler, and on Kangaroo Island, American River and Cygnet River. Estuaries: A few true rivers (eg. Onkaparinga, Port Adelaide, Wakefield Gawler Rivers), and several intermittent streams and tidal mangrove creeks (eg. American River, Clinton, Wills Creek, Port Gawler). xxiv EYRE REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE EYRE COAST MARINE BIOGEOGRAPHY 1 2 3 4 5 The Eyre Coast Oceanography Climate Coastal Geomorphology and Landforms Biology MARINE CONSERVATION VALUES 1 2 3 Significant Biological Physical Features Significant Cultural and Historical Features Current Conservation Status of the Eyre Coast BIOUNITS: 1 2 3 4 5 6 7 8 9 Nullarbor Wahgunyah Fowlers Streaky and Nuyts Yanerbie Newland Sheringa and Flinders Douglas Whidbey Page 1 EYRE REGION I MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE EYRE COAST MARINE BIOGEOGRAPHY − Western Barriers - this subprovince extends from the Head of Bight to Cape Adieu and represents a coastal distance of 122 km. 1 − Crenulate Bay and Barriers - this subprovince extends from Cape Adieu to Talia Caves on the western Eyre Peninsula, and represents a coastal distance of 576 km. − Newland Barriers - this subprovince extends from Talia Caves to Cape Finnis on the western Eyre Peninsula, and represents a coastal distance of 38 km. − Elliston Cliff - this subprovince extends from Cape Finnis to Drummond Point on the western Eyre Peninsula, and represents a coastal distance of approximately 81 km. − South-western Eyre Peninsula - this subprovince extends from Drummond Point to Cape Catastrophe on south-western tip of Eyre Peninsula, and represents a coastal distance of approximately 300 km. THE EYRE COAST The Eyre Coast is the largest coastal geomorphological region in South Australia, extending over 1,300 km, from the head of the Great Australian Bight (ie. from the West Australian border) to the entrance of Spencer Gulf (ie. to Cape Catastrophe on Eyre Peninsula). Compared to the rest of the State, this region contains some of the most remote, uninhabited, and rugged coastal regions of South Australia. Along this highly variable coastline there are spectacular cliffs and headlands, numerous offshore islands, surf pounded beaches and small sheltered embayments. Many of the offshore islands in this region provide important breeding and haul out sites of the rare Australian Sea Lion and the New Zealand Fur Seal. For the most part however, this extensive coastline faces the full force of the Southern Ocean and as such, experiences some of the highest wave energies in the State. 1.1 Biogeography of the Eyre Coast Along the southern coast of Australia, marine biogeographers recognise a major biogeographic region, known as the Flindersian Province, which extends from southwest Western Australia to southern New South Wales and includes the waters of Victoria and Tasmania. Within this broad region, the coastal waters of the Great Australian Bight are recognised as warm to cool temperate (in contrast to the cold temperate waters of the southeast of Australia, west of Robe). Within the geomorphological province known as the Eyre Province, 6 distinct coastal subprovinces have been recognised (Short et al. 1986): − Nullarbor Cliffs - this subprovince extends from wilson Bluff on the border of Western Australia, to the Head of Bight, and represents a coastal distance of approximately 209 km . Within the Flindersian Province, the Eyre Coast region (including the Nuyts Archipelago, Pearson Isles, Whidbey Isles) encompasses 3 finer-scale mesoscale biogeographical regions or bioregions have been recognised (IMCRA 1997): 1 2 3 Eucla – extending from Israelite Bay (WA) to Cape Adieu (SA). Murat – extending from Cape Adieu to Cape Bauer. Eyre – extending from Cape Bauer to Salt Creek, to Corny Point, to West Cape (Spencer Gulf), to Cape Borda (Kangaroo Island). Within this variable region, a further 11 smaller scale biounits (ie. 9 inshore biounits and 2 offshore island biounits), have been recognised: 1 Nullarbor – encompassing the Nullarbor Cliffs, extending from Israelite Bay (WA) to the Head of the Bight. Page 2 EYRE REGION 2 Wahgunyah –extending from Head of the Bight to Cape Adieu. 3 Fowlers – encompassing Fowlers Bay, extending from Cape Adieu to Point James. 4 Nuyts – encompassing the offshore Nuyts Archipelago, from Point James to Cape Bauer. 5 Streaky – ecompassing the inshore embayments from Point James to Cape Bauer. 6 Yanerbie – extending from Cape Bauer to Taila Caves. 7 Newland – extending from Talia Caves to Cape Finnis, encompassing the Newland Barrier. 8 Flinders – encompassing the offshore Investigator Group, Flinders Isles and Pearson Isles. 9 Sheringa – encompassing the Sheringa Lagoon, extending from Cape Finnis to Point Drummond. 10 Douglas – extending from Point Drummond to Point Sir Isaac, encompassing Port Douglas and Coffin Bay. 11 Whidbey – extending from Point Sir Isaac to Cape Catastrophe, encompassing the Whidbey isles, southern Eyre, Coffin Bay and Jussieu Peninsulas. 2 OCEANOGRAPHY Tides along the Eyre coast are microtidal in range and are predominantly semi-diurnal with a marked diurnal inequality between the two daily tides. Tides on the Great Australian Bight (western Eyre Peninsula) are semi-diurnal, with a mean tidal range of between 0.8 and 1 m. In southern Spencer Gulf they are of a similar range but are of a mixed type. 2.2 Water Temperature and Salinity Salinities and temperatures along the western coast of Eyre Peninsula generally vary according to the water masses that prevail in the Bight region. As such, four major water masses have been identified: − the Leeuwin Current, which has low salinities (35.0%) and high temperatures; − the central Bight water mass from the southeast Indian Ocean, which has high salinities (35.4-36.0%), and warmer temperatures (1721oC); − the West Wind Drift cold water mass has low salinities (35.0%-35.6%) and lower temperatures (9-14oC); and − the surface-flowing Flinders Current, which has a mean salinity of 35.35% and a mean temperature of 14oC. 2.1 Wave Climate The Eyre Coast is located within the `west coast swell environment' where coastal processes are dominated by a persistently high south-west swell, generated by the westerly moving low pressure cyclones south of the mainland (Davies 1980). This south-west to westerly swell ranges from less than 2 m for 50% of the year, to 2-4m for 30-45% of the year and exceeding 4 m approximately 10% of the year. Wind generated sea conditions also provide an additional source of wave energy, with seas averaging 0.5 to 1.25 m and may exceed 2 m for 1015% of the year. Breaker wave energy varies considerably along the coast. Land-locked bays and sheltered areas experience low breaker wave energy with local wind waves influencing energy regimes. Such areas include Coffin Bay, Venus Bay, Baird Bay, parts of Streaky Bay, Smoky Bay, and Tourville Bay. The open coast, however, is typified by a high deepwater wave climate and a highly variable breaker wave climate due to differences in nearshore-offshore gradients. Advective processes influence and control the salinity distribution across, and within, shelf waters. Some additional mixing is brought about by the reversal in direction of a easterly-south-easterly flow in winter, to a westerly-north-westerly flow during November to March. 2.3 Currents and Upwellings Currents Four major water masses influence the oceanography of the eastern part of the Great Australian Bight. These water masses generally occur for all or part of the year within the continental shelf and slope region off southern Australia: − the Leeuwin Current, which originates from the tropical waters of the Indian Ocean. This water mass carries warm water with low salinity along the continental shelf break as far east as 130oE and passes from west to east predominantly (though not exclusively) during winter from May to September-October (Rochford 1986). Page 3 EYRE REGION However, it is possible there is a reversal of flow in the summer with the current setting to the west along the south coast and to the north on the west coast (Rochford 1969). − a warm and very high salinity water mass, which occurs in the central and eastern half of the Great Australian Bight for most of the year. This central Bight water mass drifts to the south-east and occupies much of the shelf and slope region east of 135oE, particularly in winter (Rochford 1986). − a West Wind Drift cold water mass of lowest salinity, which is found throughout the year off the slope region of southern Australia and periodically intrudes into the shelf break, especially when the Leeuwin Current is weakly developed (Rochford 1986). − and the surface-flowing Flinders Current, which originates from the gyre south of South Australia (Bye 1972). These mixed waters have an average surface flow velocity of about 5cm sec-1. 3 CLIMATE The climate of the Eyre Peninsula coast is typically semi-arid or `Mediterranean' and as such, is characterised by hot, dry summers and cool, moist winters. It is largely influenced by mid-latitude anticyclones or high pressure systems which pass from west to east across the continent. Winter generally brings southerly to southeasterly winds and low pressure systems which travel across the Southern Ocean between 40 and 50oS, bringing frontal activity and rain. Summer brings northerly to northwesterly winds. Along the Great Australian Bight and the western coast of Eyre Peninsula, strong westerly, onshore winds have reworked the coast, resulting in extensive dune development. Most rainfall falls during winter, however it varies considerably with latitude, from approximately 500 mm in the south to less than 300 mm in the north. 4 COASTAL GEOMORPHOLOGY AND LANDFORMS Upwellings, by providing nutrients to surface waters, are sites of significant productivity. Along the Eyre Province, a periodic upwelling has been identified off the coast of western Eyre Peninsula and is characterised by an ephemeral temperature inversion within the shelf waters, south of Eyre Peninsula, during October and November (Wenju et al. 1990). The coast geomorphology is highly variable along the Eyre Coast with many islands, rocky headlands, embayments and surf pounded beaches (see Short et al. 1986, for review). This variability is a result of the continual changes in orientation and degree of protection of the coast from wave attack. The generally low summer rainfall coupled with a limestone (calcarenite) dominated coast has resulted in no rivers and only a few intermittent streams arriving at the coast. As a result there are no true estuarine environments in this province. Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperture of 14oC. The inshore coastal regions are under the influence of seasonal coldwater, nutrient-rich coastal upwellings which occur close to the coast, which can result in an offshore sea surface temperature gradient of 18oC to inshore temperatures of 11oC in inshore areas during the summer months (Ward & McLeay 1998). The region from Point Sir Isaac (Coffin Bay Peninsula) to Cape Borda (Kangaroo Island) appears to be the major focus of the coastal upwelling. There appears to be a relationship between the upwellings, and the pilchard numbers in these areas (Ward & McLeay 1998). There is also a potential link with the abundance of seabirds, seal and sea lion abundance in the region. The major open coastal landforms can be divided into rocky and sandy sections. The rocky sections consist of Tertiary limestone cliffs (with the largest section being 178 km long), Precambrian bedrock (usually capped by dune calcarenite); and Pleistocene dune calcarenite which is exposed in cliffs up to 150 m high, usually fronted by well developed shore platforms and reefs. The sandy sections include numerous beaches with backing foredunes and transgressive dunes, finer sediments composing some bay shores and usually vegetated with mangroves; and lagoonal deposits. The sandy and rocky sections are often found together, with beaches fronting stranded dune calcarenite cliffs, reefs commonly occurring off beaches, and many of the dune calcarenite cliffs capped by Holocene clifftop dunes. Upwellings Page 4 EYRE REGION Large coastal embayments occur at Coffin, Streaky, Smoky and Denial Bays. Semi-enclosed bays occur at Port Douglas, Venus, Baird and Tourville Bays. Open bays with broad entrances but protected by islands, reefs and shallow gradients occur at Coffin, Sceale, Streaky, Smoky, Decrees and Denial Bays. Open bays that are largely protected by sand barriers with only narrow inlets or entrances occur at Port Douglas, Venus, Baird and Tourville Bays. These bays contain extensive tidal delta deposits. Smaller bays include the area in lee of Cape Missiessy and Acraman Creek. Peter Island are the only oceanic stand on the entire South Australian coast. The relatively low total area of mangroves along the Eyre Coast is a result of the exposed conditions of the coast. Along the exposed sections of the Eyre Coast, mangroves are also found within the sheltered confines of the semi-enclosed Venus Bay. Numerous saline lakes have formed along the coastal areas and often occur in lee of many of the sand barriers, including the Newlands barrier, Sheringa and Cactus Beach. These lakes form because of a lack of fluvial input, periodic freshwater flooding and high evaporation rates. The subtidal habitats of the Eyre Coast have not, until recently, been systematically surveyed. However, within the region, detailed survey reports have previously been published for Pearson Island (Shepherd and Womersley 1971), the St Francis Isles (Shepherd and Womersley 1976), and Waterloo Bay (Shepherd and Womersley 1981). Further, algal distribution records from sporadic collecting in the following areas of the West Coast, have been lodged with the SA Herbarium during the past three decades: Point Fowler and Nuyts Reef (Shepherd and Womersley 1980, unpubl. report), Waterloo Bay (Shepherd, 1978; Shepherd and Turner 1982); Waldegrave Island (Shepherd 1978; Branden 1987); Pearson Island (Specht 1960; Shepherd 1982); Topgallant Island and “The Hotspot” (Shepherd and Gray 1982; Branden 1987; O’Leary 1992), Ward Island (Shepherd 1980 and 1982; Graske, no date); Sheringa Bay and West Point (Shepherd 1969). Many offshore islands and numerous reefs are scattered within this province. Of particular geological significance is the Investigator Group of Islands (particularly the Pearson Islands) which are true granitic inselbergs (island mountains). Granitic plains and inselberg landscapes are also found around Baird Bay. 5 BIOLOGY 5.1 Intertidal Ecology A diverse range of marine habitats are represented along the Eyre Coast. These include: cliffs; rocky shores; platform reefs; sandy beaches; offshore islands; subtidal reefs; seagrass meadows, small mangrove stands (Avicennia marina); sand and mud deltas. The general intertidal ecology of the Eyre Coast has been summarised by Womersley and Edmonds (1958) and more recently by Womersley (1991). It is possible to summarise the major assemblages and communities present according to the wave regime experienced in the area. This is by no means definitive, however, as local variations will occur: 1 2 3 3 Coasts of slight wave action, with sandy or muddy flats or beaches: Sheltered coasts of moderate wave action: Coasts of strong to extreme wave action (eg. steeply sloping intertidal regions of granite at Point Sinclair and Cape Carnot): Horizontal intertidal rock platforms. Mangroves (Avicennia marina) are only found in sheltered creeks or the lee of island spits at Tourville Bay (15 km2), Eyre Island (5 km2), Acraman Creek (5 km2), Laura Bay (0.5 km2) and St Peter Island (2 km2). The mangroves of Tourville Bay are of particular note as they form the westernmost stand in South Australia and the western most on the entire southern Australian coastline. The mangroves of St Intertidal rocky shores in the region are dominated in the sublittoral fringe by Cystophora intermedia. 5.2 Subtidal Ecology1 Rocky shores along the Eyre Coast are typically dominated by highly diverse subtidal macroalgal communities. Along exposed coasts, these comprise diverse red algal assemblages (dominated by Osmundaria, and species of Plocamium), and green algae (eg. species of Caulerpa), and also, large brown canopy-forming algae, such as Ecklonia radiata, and Cystophora species (eg. C. monilifera, C. moniliformis and C. platylobium). Generally, benthic biological information for the Eyre Coast, especially the Great Australian Bight, is poor, due to the remoteness and ruggedness of the area. While recent surveys by SARDI have given researchers a better understanding of the subtidal macrofloral and habitats of the region, there still remains a paucity of information on invertebrates, fish and seabirds. The following is a recent detailed account of the major marine habitats and plant life in the region by Edyvane and Baker (1998). 1 From Edyvane KS & JL Baker. (1998). Marine Biogeography of the Eastsern Great Australian Bight. Page 5 EYRE REGION communities typical of southern Australian coasts. Eucla Bioregion (eastern Great Australian Bight) The subtidal habitats of the Eucla Bioregion (from west of Cape Adieu), reflects both the high wave energy and the geology of the high-cliffed eastern Great Australian Bight and surrounding regions. Much of the area from the cliff line to 20m deep comprises bare sand stretches along the coast, with patches of calcarenite and crystalline basement rock reef (ie. granite) (Edyvane and Baker 1996). The Eucla Bioregion is one of low benthic biodiversity, with a total of only 11 species of macroalgae recorded from sites sampled at the Head of the Bight and Collosity Point, compared with an average of between 30 to 40 species along other areas of the Eyre Coast. Several reef areas within the Eucla Bioregion (Pilpuppie Well, Nuyts Reef) and in the western Murat Bioregion between Cape Nuyts and Point Bell (including the reef area in the middle of Fowler Bay), contain a diverse understorey of large red algal species, such as Amansia pinnatifida and Dictymenia, and mixed articulate corallines. Most of the reef areas in the Eucla Bioregion (and western section of the Murat Bioregion) are exposed to the strong south-westerly swell, high wave climate, and influenced by the relatively nutrientpoor, warm water (from the Leeuwin Current) which characterise the Head of the Bight region of the Great Australian Bight, and these sites usually contained algal assemblages typical of such oceanographic conditions, such as stands of Ecklonia and Scytothalia, few other macroalgal species, and an encrusting coralline understorey. The fucoids, Cystophora racemosa and C. grevillei also thrive in this region, with C. grevillei plants often growing more than 1 metre tall. The Head of Bight region is one of relatively low algal diversity and high dominance of a few major reef species. Two macroalgal brown genera dominate the benthos at the Head of Bight and Collosity Point - Ecklonia and Scytothalia, the former comprising 40 - 50% of the cover in most areas at the Head of Bight. A significant portion of the surface cover on reefs in this region (ie. 40-50%) is also encrusting coralline algae. At the Head of Bight region, low numbers of both red and brown algal species have been recorded, and both seagrass and green algae are generally poorly represented or absent in the exposed areas. Oceanographic conditions, such as the existence of strong swell and wave conditions for most of the year, possibly restricts the establishment of flora on the large expanses of bare, mobile sand between reef patches. The existence of warm water masses in the Bight may alos be responsible for the low diversity of algal species in this region, compared with cooler regions of nutrient-rich upwelling further east in the Eyre Bioregion, which permit the establishment of more the more diverse floral The benthic species composition at Cape Adieu is very similar to that at the Head of Bight, apart from the presence of Cystophora grevillei as a subdominant, which has been recorded only at the headlands of Cape Adieu and Cape Nuyts. Whilst areas within the Eucla Bioregion comprised mainly Pleistocene dune calcarenite reef with Ecklonia or Scytothalia as the dominant macroalgal cover and encrusting corallines as the dominant understorey cover, the flora of Pilpuppie Well encompasses a more diverse understorey of red algae than other areas within the Eucla Bioregion. Cape Nuyts and Nuyt’s Reef, at the boundary of the Eucla and Murat Bioregions, are similar in dominant phaeophyte cover to other areas in the Eucla Bioregion, although Cystophora species were more prevalent as subdominants, and encrusting coralline species are a less dominant feature of the understorey. Relatively high species diversity of red macroalgae has been recorded at Nuyt’s Reef, including Areschougia and Pterosiphonia (sp. nov.). The high diversity of red species at Nuyt’s Reef concurs with Shepherd and Womersley’s (1980) findings of a reef which is “rich in species” (however the site was compared only with Point Fowler). Murat Bioregion (Far West Coast) The Murat Bioregion (from Cape Adieu to Cape Bauer), encompasses several major sandy bays and numerous smaller embayments, receiving low wave energy; and exposed peninsulas, headlands and islands mainly composed of Pleistocene dune calcarenite over Precambrian crystalline bedrock (Edyvane 1995). Many islands also exist in the region, most consisting of crystalline basement rock capped with calcareous aeolianite. Seagrass-lined bays in the Murat Bioregion include the inner parts of Fowler Bay (dominated by Posidonia sinuosa and Amphibolis antarctica), Murat Bay (Posidonia community in the eastern and western parts of the bay, and Heterozostera community in the northern part); and Bosanquet Bay (mixed Heterozostera, Posidonia and Halophila communities). These bays also support substantial areas of seagrass and scattered stands of mangroves (Avicennia marina) which provide habitat for estuarine and coastal fish stocks. The deeper part of Fowler Bay (eg. 16m) comprise reef, partly covered with an unusual floral assemblage of dense red algae such as Amansia pinnatifida, Osmundaria, Amansia keutzingioides, Vidalia, Champia and other red genera. Scaberia and Sargassum species are also recorded here, as minor components of the benthic cover, but unlike other reef areas along this coast, no brown algae are dominant as reef flora. The Fowlers Bay area is a region of high red macroalgal diversity (ie. 52 red species). This contrasts with Shepherd and Womersley’s (1980) conclusion that the benthic habitats around the Point Fowler area are characterised by a “paucity of species” (purportedly Page 6 EYRE REGION due to the lack of upwelling of cool water in this coastal region compared with sites further offshore). Eyre Bioregion (Western & Southern Eyre Peninsula) Exposed areas in the Murat Bioregion, such as Point Bell, have floral affinities with areas in the Eucla Bioregion (ie. reefs are dominated by Scytothalia and Ecklonia, with a coralline understorey), while Point Bell Bay contains both seagrass communities (Posidonia and Amphibolis) and diverse red algal assemblages. The highest diversity of red macroalgae in the region occurs at Point Bell Bay (ie. 67 species, dominated by Osmundaria, but also including Dictymenia, and Amansia, and filamentous red epiphytic species such as Dasya, Herposiphonia and Micropeuce. The western Eyre Bioregion (from Cape Bauer to Cape Catastrophe) is characterised oceanographically by a moderate to high, deep water wave energy coastline (Edyvane 1995). During the late summer months, the warm temperature waters of the south west coast of Eyre Peninsula are subject to localised, cold, nutrient rich upwellings (Wenju et al. 1990). The coastal geomorphology of the western Eyre Bioregion is highly variable, resulting from changes in orientation and degree of protection of the coast from wave attack (Short et al. 1986). There is a diversity of major coastal and marine habitat types in the Eyre Bioregion, including cliffs, rocky shores, intertidal platform reefs, sandy beaches, offshore islands, subtidal reefs, seagrass meadows, small mangrove stands, and sand and mud tidal deltas (eg. Venus Bay). Within the western Eyre Bioregion there are many offshore islands and numerous reefs, such as the Investigator Group of islands, which are true granitic inselbergs and thus of geological significance (eg. Pearson Islands) (Edyvane 1995). In the less exposed areas of the Murat Bioregion, in the lee of the Nuyts Archipelago (protected from the full force of the south-westerly swell conditions), reef communities generally contain higher floral diversity. Reef areas in the Murat Bioregion, such as Cape D’Estrees, Franklin Island and Cape de Mole, are characterised by mixed Cystophora and Sargassum species, Osmundaria and/or often a diverse understorey of mixed red species. Further east, in the Eyre Bioregion, more temperate, cooler water species occur, such as Acrocarpia and the rough-water, south-eastern species of Cystophora, C. platylobium, occur with mixed red understorey assemblages dominated by Plocamium and Phacelocarpus species. The large brown Acrocarpia paniculata is generally uncommon on the eastern Great Australian Bight - western Eyre Peninsula coast, but is a major component of reef flora at cooler water locations such as the southern end of Eyre, Yorke and Fleurieu peninsulas. The benthic habitats in shallow (5m) waters off Cape D’Estrees are mainly characterised by stands of mixed Sargassum species over sponge beds, interspersed with Posidonia sinuosa meadows. At the ecologically significant Franklin Islands, the exposed western side at 15m contains a reef floral assemblage similar to the exposed areas in the Eucla Bioregion, dominated by the fucoid Scytothalia, with an understorey of encrusting coralline algae. In contrast, the less exposed eastern side of the Franklin Islands are characterised by a reef community of mixed Sargassum and Cystophora species, similar to the reefal area off Cape D’Estrees, to the north. The Franklin Islands region contains a great diversity of brown algae (ie. 24 species, including 9 species of Sargassum). Uncommon species at the bioregional level, such as the red algae, Trigenia umbellata and T. australis form a significant component of the habitat in areas on the eastern end of the Murat Bioregion (ie. Cape de Mole and Cape Bauer). Cape de Mole is notable for 6 species of green algae (higher than the number of Chlorophytes recorded at any other site in the eastern Great Australian Bight), and by the apparent local abundance of the rare brown alga Scoresbyella profunda). Whilst the region is mainly characterised by temperate Flindersian elements, such as Ecklonia radiata and Cystophora species, the upwelling may explain the common occurrence in this bioregion of diverse, cooler water, red algal communities dominated by mixed Plocamium and Phacelocarpus species, and the occurrence of more easterly (cooler water) brown macroalgae, such as Acrocarpia paniculata. Red algae dominate the benthos on coralline-covered reef sites, particularly at Weyland Point (seaward of Venus Bay) and Point Whidbey, in the far south of the region. The large red algae Osmundaria forms the main cover on many reefs (eg. Anxious Bay), where it occurs with an understorey of mixed red species such as Phacelocarpus and Plocamium costatum and P.dilatatum. The cooler temperate brown algae Acrocarpia paniculata occurs as a reef dominant in this region (eg. at Weyland Point and also, along the southern end of Eyre Peninsula, at Liguanea Island). The reefs of Liguanea Island also comprise a dense understorey of mixed hydroids and ascidians. Shallow, sheltered bays in the region, such as Venus Bay, are dominated by the seagrass Heterozostera, along with mixed Cystophora species, such as C. siliquosa and C. monilifera. Other more exposed bays in the region, such as Searcy Bay, are dominated by a rich assemblage of mixed red, green and brown algae, such as Phacelocarpus and Plocamium species, Caulerpa flexilis, and Homeostrichus, which form a dense understorey. The green Caulerpa species C.flexilis and C.obscura were also dominant at Point Labatt, where the understorey comprises mixed red and brown species similar to Searcy Bay. Page 7 EYRE REGION 5.3 Fish The marine fish fauna found in the waters surrounding Eyre Peninsula is typical of the Flindersian Province of southern Australian coastal waters (Glover & Olsen 1985). As such, many of the species recorded in South Australian waters, have also been recorded in southern and southwestern Western Australian waters, and to a lesser extent, in the waters of western Victoria and northwest Tasmania. For instance, Hutchins and Thompson (1983) reported that of the 344 species they listed for south-western Western Australia, 61% extended eastwards to, at least, off South Australia. There are some 300 species of known marine fish recorded off Eyre Peninsula down to the base of the continental slope, which represents approximately 67% of the species recorded from all South Australian marine waters (Glover 1982). Most of the species along the Eyre coast tend to be inshore with fairly permanent resident populations. However, there are some regular migratory visitors such as the Australian Salmon and occasional oceanic vagrants such as oceanic Sunfish (Mola sp.), Basking Shark (Cetorhinus maximus), Black Marlin (Makaira indica), and the Lizardfish (Saurida undosquamis). Their presence in these waters can be attributed to the easterly flowing Leeuwin Current (Glover & Olsen 1985). Among the native freshwater species, which spend part of their life cycle at sea - the Common Galaxias (Galaxias maculatus) and the Black Bream (Acanthopagrus butcheri), have been recorded in the Tod River. The Common Galaxias has also been recorded in the North Shiels Creek, Lake Wangary and a tributary of Little Swamp (Glover & Olsen 1985). Small-Mouthed Hardyhead (Atherinasoma microstoma) have been recorded in the permanent spring-fed saline waters of Lakes Hamilton and Newland, on the west coast south of Venus Bay, while eleven normally marine species of fish have been recorded in Lake Wangary, which has a connection with the sea via Minniribbie Creek. Marine and primarily marine species are likely to enter and frequent the estuaries and lower reaches of other coastal waterways, eg. the Congolli (Pseudaphritis urvillii). However, most seaconnected waterways occur along the east coast of Eyre Peninsula in the Gulfs Province. bellied Sea-eagle, Sooty Oystercatcher, Pacific Gull, Fairy Tern, Crested Tern, Rock Parrot, and the Fleshy-footed Shearwater (Smith Island) (Eckert et al. 1985). The Australian Raven breeds on myallbluebush plains and on islands off the western coast. Some of the islands are home to colonies of rare or nearly extinct birds. For instance, the Southern Stone Curlew, which is found on Thistle and Boston Island, is largely extinct as a breeding bird on the South Australian mainland. There are also large breeding grounds for the Cape Barren Goose off the west and south coasts and on the Sir Joseph Banks Group (Robinson et al. 1982). Other species breed on more protected, inshore islands along the Eyre coast. Goat Island in Coffin Bay, is of particular significance in being one of the most accessible South Australian breeding grounds of the Rock Parrot. The ABC islets in Venus Bay also carry breeding populations of this species and together with Jones Island and Little Eyre Island are of further significance for their breeding colonies of the Australian Pelican. Another local breeding bird of sheltered islands is the Eastern Reef Egret (Eckert et al. 1985). 5.5 Marine Mammals The Eyre Coast is home to many species of marine mammals, particularly, cetaceans. At least 17 species of cetaceans have been recorded in the Great Australian Bight, and of these at least one, the Southern Right Whale, is known to calve in the area during May to November (Kemper & Ling 1991). Some species are migratory, such as Blue Whales, Sperm Whales, Minke Whales, Humpbacks, Rorquals, as well as the endangered Southern Right Whale. Their presence may be due to the squid that are believed to be abundant in the Ceduna canyons and just off the continental shelf (Kemper & Ling 1991). Killer Whales have also been recorded and their presence is probably related to the abundance of pinnipeds along the western Eyre Peninsula. The Head of Bight, in particular, is an important calving, nursing and breeding area for Southern Right Whales. This may be due to the warmer waters brought in by the Leeuwin current since cetaceans are born with little blubber. 5.4 Seabirds There are many birds that breed wholly or largely on the offshore islands of South Australia (including those located along the Eyre Coast). These include the Little Penguin, Short-tailed Shearwater, Whitefaced Storm Petrel, Black-faced Shag, Eastern Reef Egret, Cape Barren Goose, WhitePage 8 EYRE REGION The warm Leeuwin current has also been suggested as a mechanism for bringing occasional individuals of tropical species such as Bryde's Whale into South Australian waters (Kemper & Ling 1991). Pelagic organisms, such as the phytoplankton and zooplankton in the Great Australian Bight, have also been classified as having tropical origins (Markina 1976). In addition to cetaceans, the Eyre Coast, particularly the offshore islands, also contains significant colonies of the New Zealand fur seal (Arctocephalus forsteri) and the rare Australian sea lion (Neophoca cinerea). By extrapolating from the number of sea lion pups found in the 1994 survey, the population of the Great Australian Bight region in South Australia has been estimated at between 613 and 744, which represents approximately 9.3% of the South Australian population or 6.6% of the total world population for this species (Dennis & Shaughnessy 1996). The significance of the populations of Australian sea lions in the Great Australian Bight is further increased because it is very likely that the populations were never commercially harvested - like many other populations along the southern coasts and islands of Australia last century. Generally, to the point of extinction. This is principally because of the isolation and general inaccessibility of the Great Australian Bight coast, both, from land and sea. Thus the populations have remained intact, providing probably one of the greatest sources of genetic diversity for this species in the world, and also, a very important genetic and geographic bridging population between the South Australian and Western Australian sea lion populations (Dennis & Shaughnessy 1996). The existence of a distinct tropical element in the fauna and flora of the Great Australian Bight is thought to be due to the Leeuwin Current, bringing pelagic species and larvae from other regions [see below]. The distribution of such tropical benthic fauna due to dispersal by the Leeuwin Current underlines the difficulty in applying biogeographic boundaries to biological systems. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND 1.1 Biological Tropical Element in the Demersal and Pelagic Fauna of the Great Australian Bight The fauna and flora of the Great Australian Bight region is marked by a characteristic tropical element. Among the benthic invertebrate fauna, many of the echinoderm species recorded from South Australia originate from the Indo-Pacific region (Maxwell & Cresswell 1981). For instance, some 20 of the 84 species of hydroid recorded from South Australia have their principal distribution in the warm waters of the Indo-Malay region. Other echinoderms of Indo-Pacific origin include the Basket Star (Euryale aspera), and the holothurians, Pentacta anceps and Pentacta quadrangularis (Maxwell & New Zealand Fur Seal (Arctocephalus forsteri) and the rare Australian Sea Lion (Neophoca cinerea) Both the New Zealand Fur Seal (Arctocephalus forsteri) and the rare Australian Sea Lion (Neophoca cinerea) have significant breeding colonies in South Australia. The largest colonies of these two resident mammals occur on the islands off Eyre Peninsula and represent a major proportion of the world population for both these species (Watt & Ling 1985). Dangerous Reef in southern Spencer Gulf, in particular, is one of the three major breeding areas for Australian Sea Lions in South Australia (Watt & Ling 1985, Robinson & Dennis 1988, Gales 1990, Gales et al. 1994). Other major breeding areas for this species in this region include Purdie, Olive and Franklin Islands (Nuyts Archipelago). Further, Point Labatt near Streaky Bay represents the only and largest mainland colony of Australian Sea Lions in Australia. The Neptune Islands are one of three major breeding areas of New Zealand Fur Seals in South Australia (along with Kangaroo Island and the islands off the Jussieu Peninsula). Together the fur seals from the Neptune Islands comprise almost 13,800 seals and represent approximately 61% of the estimated South Australian population or 51% of the total Australian population for this species (Shaughnessy 1990, Shaughnessy et al. 1994). The islands of the Nuyts Archipelago and Sir Joseph Banks Group (Spencer Gulf) have smaller but nevertheless important colonies of Fur Seals and Sea Lions, and breeding also takes place at some of these sites. However, there is considerable mobility between haul-out sites. Cresswell 1981). Page 9 EYRE REGION Southern Right Whales (Eubalaena australis) The Eyre Coast (and Great Australian Bight) is a region of world significance for the breeding of the endangered Southern Right Whale (Eubalaena australis). Along this coast are located the three critical nursery areas for calving and mating of Southern Right Whales in South Australia: Moodyara, Twilight Cove and the Head of the Bight (Ling & Needham 1991). At least 40 -50 whales visit the Head of the Great Australian Bight between May and November each year. They usually frequent the waters within 1 km offshore, and are easily seen from the coastal cliffs. Calving occurs in June and nursing continues until November. Mating may also occur during this time. Whales seen in South Australian waters one year have been sighted in Western Australia during another year, suggesting that the whales may "home in" on different areas according to particular phases of their reproductive cycle (Ling & Needham 1991). The varied shoreline with its embayments and protected waters are probably important for shelter in adverse weather and may be calving grounds for some species (Kemper & Ling 1991). Other Cetaceans The Great Australian Bight region generally is also becoming increasingly recognised as a significant seasonal habitat for many other species of rare and endangered marine mammals. At least 17 species of cetaceans have been recorded including Blue Whales, Sperm Whales, Minke Whales, Rorquals and Humpbacks (Kemper & Ling 1991). In the National Cetacean Action Plan (Bannister et al. in press), the Blue Whale (Balaenoptera musculus musculus) is listed as `endangered’, the Humpback Whale (Megaptera novaeangliae) is `vulnerable’, while the Sperm Whale (Physeter macrocephalus) is listed as `insufficiently known’ and `potentially vulnerable’ under the IUCN Red List categories. Blue, Sperm, Minke (Balaenoptera acutorostrata) and Humpback Whales are reasonably commonly sighted, aswell as stranding around the Great Australian Bight. Possibly resident cetaceans are the Beaked Whale, Killer Whales (Orcinus orca) and Risso’s Dolphin (Grampus griseus). Individuals of tropical species such as Bryde’s Whale (Balaenoptera edeni) are occassionally seen in South Australian waters, and it has been suggested that they have travelled on the warm Leeuwin Current (Kemper & Ling 1991). Bottlenose Dolphins (Tursiops truncatus) have been seen on many occasions playing amongst Southern Right Whale groups (Ling & Needham 1988, Bannister 1993). The presence of cetaceans, particularly Killer Whales (Orcinus orca) is probably related to the abundance of pinnipeds along the western Eyre Peninsula. Owing to its remoteness and ruggedness of the Bight region, this area has not been studied in any detail. As such, there is generally a paucity of biological information. Fauna and Flora of the Offshore Islands There are 47 islands between Cape Catastrophe and the islands of the Nuyts Archipelago. The major groups are the Whidbey Islands, the Investigator Group which includes the relatively large Flinders Island (25km2), and Nuyts Archipelago. They are important because most are undeveloped and uninhabited, thus providing important habitats and ecological refuges for species which have become extinct on the mainland. Some of the islands of particular conservation significance include the Franklin Islands (Nuyts Archipelago) which contain the last known population in the world of the Greater Stick-nest Rats (Leporillus conditor); St Francis, Purdie, Lounds, Olive and the Neptune Islands which contain significant breeding colonies of rare Australian Sea Lions and New Zealand Fur Seals; the Eyre Islands which contain completely undisturbed vegetation including mangroves and samphire flats; and St Peter Island which also contains significant stands of mangroves, as well as re-introduced populations of Stick-nest Rats and Brush-tailed Bettongs, and a spectacular 4 km long sand spit in lee of the island. Coastal Wetlands of National Importance A Directory of Important Wetlands in Australia (ANCA 1996) list the following coastal wetlands of national importance along the Eyre Coast: 1 2 3 4 5 6 7 Davenport Creek Streaky Bay Point Labatt Baird Bay Lake Newland Lake Hamilton Coffin Bay Coastal Wetland System Page 10 EYRE REGION Extensive Seagrass Meadows The sheltered embayments of the Eyre Coast, particularly Streaky and Smoky Bay (ie. Streaky Biounit), and Port Douglas (ie. Douglas Biounit), support extensive seagrass meadows. These extensive seagrass meadows flourish in shallow clear waters, generally in waters less than 15m, and provide the basis for the significant productivity of the coastal regions in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 86,163 ha in Streaky and Smoky Bay, and 8,567 ha in Port Douglas. Together, the seagrasses of the Eyre Coast represent approximately 15% (ie. 1,407 km2) of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Seagrass meadows are particularly important for a number of reasons: as primary producers they occupy the base of the food chain; they provide important or “critical” habitats such as nursery, breeding or feeding areas for the juveniles and adults of many fish, crustaceans and other marine animals, including a large number of commercial species (Bell & Pollard 1989, Howard et al. 1989); and their extensive root and rhizome systems stabilise nearshore sediments and sand banks, enhancing coastal water clarity and reducing coastal erosion (Scoffin 1971). Seagrass meadows also support a prolific skeletal biota as infauna and epiphytes, which in turn, provides the carbonate basis for sediments in the region. Mangrove and Coastal Saltmarshes The sheltered embayments of the Eyre Coast (ie. Tourville Bay, Murat Bay, Denial, Bosanquet, Smoky Bay, and Streaky Bay) contain extensive areas of tidal wetlands in South Australia (and the most westerly records of mangrove forests in South Australia) (Edyvane 1996). Mangrove forests in the region while small are significant (particularly in Tourville Bay) as they represent the most westerly distribution of mangroves in South Australia, and the largest stands between Spencer Gulf and Exmouth Gulf in Western Australia. Associated with the mangrove habitats are biologically rich mud flats, coastal saltmarshes and seagrasses. Together, mangrove and saltmarsh communities along the South Australian coast total approximately 82,000 ha, with the largest communities occurring in Spencer Gulf (46,000 ha) and Gulf St Vincent (20,000 ha). A total of 9 000 ha of mangrove and saltmarsh communities are recorded on the west coast of Eyre Peninsula (9,000 ha). Other substantial communities occur in lower Spencer Gulf (6,000ha), on and on Kangaroo Island (7,000 ha) (DELM 1993). Mangrove forests comprise a single species, the Grey Mangrove, Avicennia marina, which forms a low woodland forest extending from mean sea level to spring high-tide level. Progressively higher vegetated zones are a Halosarcia-Sarcocornia (saltmarsh) association, a Sclerostegia-Halosarcia (saltmarsh) association and an Atriplex (saltbush) association (Chinnock 1980). These tidal wetlands are areas of considerable productivity and represent significant feeding habitats for waterfowl and waders, and also represent key nursery, feeding and breeding areas for many economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Conspicuous algal mats, which form as a result of sediment trapping by filamentous blue-green algae are associated with both, the mangrove and saltmarsh flora. A variety of marine organisms, mostly gastropods, bivalves, polychaetes and crustaceans, also live in and on the mangrove mud, and are a key food source. 1.2 Physical Leeuwin Current The Leeuwin Current is a major eastern boundary current system off the west coast of Australia. This warm, low salinity current originates from the tropical Indian Ocean and during winter from May to September-October, flows south along the shelf break of the west coast, along the southern coast of Australia, to the eastern Great Australian Bight (to approximately 130oE). For coastal and offshore fisheries, the Leeuwin Current is intimately linked to the population dynamics of many of Western Australia's and to a lesser extent, South Australia's, commercially important species. As such, the life history characteristics, such as spawning, migration, recruitment and feeding patterns, and ultimately the overall production, of many species along the western and southern seaboard of Australia have evolved under the influence of such a current system. Almost all of the major economically important fish stocks off the western and southern coasts of Western Australia are influenced to some extent by the Leeuwin Current (Lenanton et al. 1991). Some pelagic species use the Leeuwin Current to disperse from the north-western waters of Australia to the southern seaboard of Australia. For instance, the Southern Bluefin Tuna (Thunnus maccoyii) spawns in the Java Sea and migrates southward along the western Australian coastline and eastward along the southern coast of Australia. It is an important commercial species and its distribution and abundance is influenced by the seasonality, strength and timing of the Leeuwin Current. Page 11 EYRE REGION Other commercial pelagic fish whose distribution and abundance is affected by the Leeuwin Current include, Mackerel (Scomber australasicus), Horse Mackerel (Trachurus declivis), Australian Salmon (Arripis truttaceus), and Australian Herring (Arripis georgianus). Southern Bluefin Tuna and the latter two species are particularly important fisheries in South Australian waters. In South Australia, the Leeuwin Current also brings warm waters to the Head of the Great Australian Bight. Since cetaceans are generally born with little blubber, this is thought to explain the existence of several critical breeding areas for the endangered Southern Right Whale in this region. The warm Leeuwin current has also been suggested as a mechanism for bringing occasional individuals of tropical species such as Bryde's Whale into South Australian waters (Kemper & Ling 1991). Coastal Upwelling and Southern Eyre Peninsula Productivity – Seasonal coldwater, nutrient-rich coastal upwellings, by providing nutrients to surface waters, are sites of significant biological productivity. These areas are often correlated with high levels of productivity and biodiversity. Along the Eyre Coast, a periodic coastal upwelling has been identified off the coast of west coast of Eyre Peninsula to western Kangaroo Island, and is characterised by an ephemeral temperature inversion within the shelf waters, south of Eyre Peninsula, during October and November (Wenju et al. 1990). The inshore coastal regions under the influence of result in inshore temperatures of 11oC during the summer months, to offshore sea surface temperatures, away from the influence of the upwelling, of 18oC (Wenju et al. 1990). The region from Point Sir Isaac (Coffin Bay Peninsula) to Cape Borda (northwestern Kangaroo Island) appears to be the major epicentre of the coastal upwellings, and there appears to be a relationship between the upwellings, and the pilchard numbers in these areas (Ward & McLeay 1998). There is also a potential link with the abundance of other economic species (abalone, Southern Rock Lobster) and also, local seabird, seal and sea lion abundance in the region. Benthic biodiversity and productivity (particularly for marine macroalgae and benthic invertebrates) is also very high in this region. Offshore Islands a subaerial bedrock basement, preserving a rich history of Holocene sea-levels and evolution in their beach and foredune ridges, mangrove stands and samphire flats. St Peter Island also contains mangroves, as well as a spectacular 4 km long spit in lee of the island. Some of the islands also have significant European heritage value. "Geological Monuments" There are 15 "Geological Monuments" identified by the South Australian Museum and Geological Society of Australia that are associated with the coastline or offshore waters of the Eyre Coast (further details are supplied in the relevant biounit): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Merdayerrah sandpatch Clare Bay Point Le Hunte (by Point Sinclair) Laura Bay Eyre Island Point Brown Point Collinson (northern Streaky Bay) Acraman Creek Smooth Pool headland, near Sceale Bay, Westall Peninsula Talia Caves: coastal landform. Drummond Point Coastal outcrops of old Precambrian rocks on southern (and southeastern) Eyre Peninsula. Whalers Way-Fishery Bay to Cape Carnot Cape Carnot Cape Catastrophe Further details of these areas are supplied in the relevant regional biounit descriptions below. 2 SIGNIFICANT CULTURAL HISTORICAL FEATURES AND The following description of Aboriginal and European history along the Eyre Coast is necessarily brief and selective, providing a focus on coastal and maritime history. Only details of Aboriginal historical and cultural sites that have been published in the available literature are described. Aboriginal sites, objects and remains are protected under the South Australian Aboriginal Heritage Act (1988), and a register of such sites, objects and remains is kept with the Aboriginal Heritage Branch of the South Australian Department of Environment, Heritage and Aboriginal Affairs. In addition their ecological importance, the islands between Cape Catastrophe and the islands of the Nuyts Archipelago are also important geologically, because they provide insight into the geology of the adjacent shelf. Islands of particular significance include, the Investigator Group of Islands (particularly the Pearson Islands) which are true granitic inselbergs, and the Eyre Islands (Little Eyre and Eyre), which are the only islands without Page 12 EYRE REGION 2.1 Aboriginal Traditional uses still occur at Yalata (near Fowlers Bay) and more recently, Yaralina (Murat Bay). Although PALO has expressed interest in the joint management of a number of cultural sites in Coffin Bay and at Hill Bay, near Drummond Point. History The Aboriginal history of the Eyre Coast is complex and difficult to summarise briefly. At the time of early European settlement, however, there were two dominant Aboriginal sociocultural systems; the Banggala and the Gugada (Berndt 1985). Prior to 1878, the Gugada people were occupying country between Venus Bay and Point Brown, along the coast and inland to the Gawler Ranges; but they were not restricted to the area and frequently came into Port Lincoln and Fowlers Bay. Culturally, if not socially, they virtually overwhelmed, especially the Wirangu, and were certainly making inroads into both Banggala and Nauo territories at the time of European settlement. The Wirangu people occupied the northwestern side of the Peninsula, along the coast from Fowlers Bay to south of Streaky Bay (Tindale 1974). The Wirganu, essentially not a Western Desert population, were probably forced southward by expanding Desert groups (Berndt 1985). According to Tindale (1974), Banggala country extended as far south as Franklin Harbour, then to Tumby Bay and then into Port Lincoln with the establishment of European settlement. He identified two divisions in this group: the Nauo and the Banggala. The Nauo probably occupied the southern Eyre Peninsula from Venus Bay, south to Port Lincoln and west to Franklin Harbour. The Nauo land of the dead was on islands in Spencer Gulf, while the Banggala located theirs on islands to the west, probably out from Coffin Bay (Angus 1847), implying considerable movement and displacement of local groups must have taken place prior to European contact. It is not known whether the Nauo originally occupied the western area of the peninsula or were forced in that direction by the Banggala. Cultural Sites Sparse occupation and sites because of the arid environment. All coastal sites along the Eyre Coast are all surface sites with no stratigraphy - have been eroded by natural processes. However, most sites on the west coast are not been disturbed by European activities. Sites of cultural significance along the Eyre Coast generally decrease from north to south, as human presence and activity increases. As such, there exists a number of coastal sites in the Fowler's Bay - Elliston region worthy of consideration for listing on the Register of the National Estate (A. Nicholson, pers. comm.). These include, the site complex at Point Brown, the middens at Acramen Creek, and the middens at Corvisart Bay (Nicholson 1991). The region encompassed within the Murat Bioregion represents one of the most significant regions of Aboriginal heritage along the whole of the Eyre Coast (A. Nicholson pers.comm.). The remoteness of the region has resulted in many sites remaining completely undisturbed by European activities. Nicholson (1991), in a survey of cultural sites from Fowlers Bay to Elliston, identified the following occupation sites as being particularly significant: − − − Point Brown 4 (approximately 400-500 years old): a recent occupation complex consisting of middens and an artefact manufacturing site. To be recommended for National Estate listing (Nicholson pers.comm.). Acraman Creek 4 (approximately 6,700 years old): a discrete occupation site consisting of four middens. To be recommended for National Estate listing (Nicholson pers.comm.). Corvisart Bay 3, Granites (approximately 67,000 years old): a discrete occupation site consisting of three middens. To be recommended for National Estate listing (Nicholson pers.comm.). In addition to these outstanding sites a number of other occupation sites of cultural significance have also been identified by Nicholson (1991): − − − − Tourville Bay 7, Nadir Landing: a discrete occupation site: an artefact or stone scatter. One of the ten largest occupation sites in the Eyre Province. Tourville Bay as a region is considered to be of moderate Aboriginal significance and sensitivity, however the rocky coast within the bay is considered to be of high sensitivity and moderate significance (Nicholson 1990). Perlubie 2, near Eba Island: a discrete occupation site 20 m from MHWM: an artefact or stone scatter. One of the ten largest occupation sites in the Eyre Province. Corvisart 7, Yanerbie sandpatch: a discrete occupation site consisting of cultural, animal bones. Venus Bay 7: an occupation site complex, consisting of one midden and an artefact or stone scatter. Page 13 EYRE REGION The region between Fowler's Bay and Streaky Bay is also culturally significant for the dominance of `natural' Aboriginal fishtraps in this region (Martin 1988). These fishtraps used modified natural features such as rock platform reef formations, tidal pools and shellgrit ridges. None of these types of traps have been recorded elsewhere along the west coast of Eyre Peninsula. − Natural Aboriginal fish traps have been found at Rocky Point (1), Tourville Bay (2), Murat Bay (10), Halfway Camp, in Murat Bay (1), Point Dillon-Cape Missiessy (1), Smoky Bay (1), and Eba Island (1) (Martin 1988). − `Constructed' Aboriginal fishtraps, consisting of woven wooden traps, have been recorded at Duckponds Creek, in Murat Bay (1) and on the north coast of St Peter Island (1) (Martin 1988). The Murat Bay Aquaculture Management Plan (1991) reports the following areas of Aboriginal significance in this region2: − The rocky coast of the Point James Zone has Aboriginal sites of high sensitivity and moderate significance, whilst the sandy coast has Aboriginal sites considered to be of moderate sensitivity and low significance (Nicholson 1990). − The rocky coast occupied by Ceduna and Thevenard probably had Aboriginal sites of high sensitivity and moderate significance, but unfortunately most of this area is now highly developed and the sites disturbed (Nicholson 1990). − Aboriginal sites along Cape Beaufort are considered to be of high sensitivity and moderate significance (Nicholson 1990). − The rocky coast of the Waterwitch Aquaculture Zone has Aboriginal sites of high sensitivity and moderate significance; the sandy coast has sites of high sensitivity and low significance. The beach east of Wittlebee Point and the southern part of Smoky Bay have sites of moderate sensitivity and significance. − The rocky coast of the Wittlebee Zone has Aboriginal sites of high sensitivity and moderate significance. − In Laura Bay, sites of high sensitivity and moderate significance occur on rocky coast, while sites of moderate significance in sandy areas. sensitivity and 2.2 European Early Discoverers The first explorer to touch the South Australian coast was the Dutchman, Francors Thyssen in the 'Gulden Zeepard' in 1627. He sailed eastwards across the Bight as far as the Nuyts group of islands, but turned back because of the inhospitable coast. It was more than 150 years later when the Frenchman D'Entrecasteaux sailed eastwards to the Nuyts Archipelago and then to Van Diemen's Land. The exploration and mapping of the coast of Eyre Peninsula began with the Englishman Flinders and his crew who arrived aboard the 'Investigator' at Fowlers Bay on 28 January 1802. He proceeded in an easterly direction charting the outline of the Peninsula and naming features after places in his native Lincolnshire, after supporters of the voyage, and from the way the features appeared to him (eg. Smoky Bay). He also named islands after his crew, such as at Cape Catastrophe where the Master of the 'Investigator' (Thistle), and seven crewmen were drowned. Memory Cove was so named to commemorate those lost. Following the initial discoverers came whalers and sealers, and before settlement had begun, there was a thriving whaling, sealing and fishing industry. The remains of early sealers' huts and whaling stations may still be seen on some of the beaches and offshore islands (Watts & Ling 1985). The South Australian Company, in addition to its operations at Encounter Bay on Fleurieu Peninsula, established whaling stations on Thistle Island at the foot of Spencer Gulf and at Sleaford Bay on the tip of Eyre Peninsula (Colwell 1969). Port Lincoln was founded in March of 1839, and increased settlement and agriculture began on a broader scale in the region. 2 "Sensitivity" refers to the quantity of sites in a particular region :the more sites there are in a region, the more "sensitive" it is thought to be. "Significance" refers to the quality or importance of sites within a given region and is defined according to certain criteria such as significance to the archaeological discipline or to the Aboriginal community. Page 14 EYRE REGION Shipwrecks Wrecks situated in State waters may be protected by proclamation under the State legislation, ie. Historic Shipwrecks Act 1981. As yet, no shipwrecks within the State waters of southern Eyre Peninsula have been declared historic (under the Historic Shipwrecks Act 1981). However, three shipwrecks and some whaler’s anchors older than 75 years are located in Commonwealth waters and are automatically protected under the Commonwealth legislation (ie. Historic Shipwrecks Act 1976): the `Mary Ellis’ (which has been located); the `Amelia’ which is located in Avoid Bay; the HMS `Investigator’ cutter near Cape Catastrophe; and possibly one or two whaler’s anchors in Fishery Bay. Although there are no recorded historic shipwrecks or relics for this section of coastline, it is likely that they do exist. The absence of protected sites along the Eyre coast is probably due to the lack of research rather than a lack of significant sites (B. Jeffery, State Heritage Branch, pers. comm.). 3 CURRENT CONSERVATION STATUS OF THE EYRE COAST Prior to 1996, only one, small Aquatic Reserve had been declared in this region (ie. Point Labatt). This reserve was established specifically for the protection of a breeding colony of the rare Australian Sea Lion and no public access to this reserve is permitted. In 1996, the SA Government declared South Australia’s first multiple-use Marine Park, the Great Australian Bight Marine Park, at the Head of the Bight, adjacent to the Nullarbor National Park. The park comprises both, a Marine Sanctuary (managed under the Fisheries Act), and also, a National Park (managed under the National Parks and Wildlife Act) and is the largest Marine Protected Area in South Australia (168,300 ha), comprising approximately 85% of the total area of MPAs in SA. The park was established primarily to protect critical nursery areas of the endangered South Right Whale at the Head of the Bight, and several breeding colonies of rare Australian Sea Lions. `Netting closures' have also been declared in the region, however these areas have generally not been formally recognised as MPAs (see Ivanovici 1985, McNeill 1991). Present MPAs in this region include: − Marine Reserves Point Labatt Aquatic Reserve (230 ha) − Marine Parks Great Australian Bight Marine Park (129o 132oE, 3 nautical miles offshore), comprising: − Marine Sanctuary Great Australian Bight Marine Park Whale Sanctuary (43,587 ha) − National Park Great Australian Bight Marine National Park (124,732 ha) Netting Closures − − − − − − − Fowlers Bay Denial and Smoky Bay Streaky Bay Baird Bay Venus Bay Waterloo Bay Coffin Bay Page 15 EYRE REGION – NULLARBOR BIOUNIT I MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE NULLARBOR BIOUNIT This biounit extends from Wilson Bluff on the border of Western Australia3, to the Head of Bight, and covers an area of 842,642ha and a coastal distance of 209 km. It faces south into the Great Australian Bight. (3 This is the geographical limit for the Eyre Peninsula Coast Protection District.) No seagrass habitats have been recorded in the region. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY Predominantly high wave energy associated with the high cliff coastline. Moderating wave energy in the Head of Bight. 2 GEOLOGY AND GEOMORPHOLOGY3 COASTAL The first 30 km eastwards from the Western Australian border consists of 90 m high Tertiary Limestone cliffs and a large sand patch at Merdayerrah. Here, sediments deposited at the base of the Nullarbor Cliffs during the Pleistocene have lithified, forming 400-1,000 m wide dune calcarenite ramps. These have been partly transgressed by Holocene dunes which have also overtopped the 90 m high Nullarbor Cliffs in places. The existing transgression is likely to be due to past episodes of shoreline regression, frontal dune instability and the low rainfall. The next 179 km from the Merdayerrah Sandpatch eastward consists of an unbroken line of towering limestone cliffs until the Head of the Bight. There are small gradients in cliff height and changes in orientation which provide the only variation in an otherwise uniform coastal geomorphology. Inland of the cliff line, the plain extends as a near horizontal surface. 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly limestone cliffs, and some sandy beaches. − Of the total inshore subtidal habitats mapped in the biounit (15,744ha), sandy bottoms comprise 11,836 ha (75.2%), and limestone reefs comprise 3,908 ha (24.8%). 3 The coastal nearshore marine habitats of this biounit comprise mostly sand out to at least 2-3km, interspersed with small narrow patches of low profile limestone reef (Edyvane & Baker 1996, Edyvane & Andrews 1996). East of the Head of Bight (131o30’E) to the Western Australian border (132o00’E), the nearshore area is characterised mainly by sandy habitat (69%), interspersed with patches of limestone reef which comprise approximately 31% of the total nearshore habitat area (Edyvane & Baker 1996, Edyvane & Andrews 1996). Within this region, the major nearshore reefal habitats appear to occur east of the Dog Fence (131o40’ E), with reefal habitats comprising approximately 26% of the total habitat area, compared with 5% of the total area in the region west of the Dog Fence. Major Benthic Communities • Macroalgal − The marine benthic habitats of this region within the Great Australian Bight has been the subject of few studies. Biological surveys conducted by researchers from SARDI in June 1994 indicate subtidal benthic communities assemblages in the region are typical of warm to cool temperate waters, and high swell wave conditions. On the rocky limestone reefs within the Great Australian Bight Marine Park, subtidal macroalgal communities are dominated by the kelp, Ecklonia radiata and the fucoid Scytothalia dorycarpa (Edyvane & Andrews 1996), and articulated (eg. Amphiroa sp.) and encrusting coralline algae. Of particular interest is the presence of a suspected relic tropical assemblage in the macroflora, indicated by the presence of an undescribed fucoid, Sargassum spp. No seagrass communities have been recorded within this biounit. From Eyre Coast Protection District Study Report. Page 16 EYRE REGION – NULLARBOR BIOUNIT & Burnell unpubl.data, cited in Burnell & Bryden in press). Recent studies at the Head of Bight have confirmed the size and density of the aggregation, with a total of 45 whales counted within the site on one day (ie. August 1994), and a total of 101 individual whales (based on photo-identifications) recorded during the winter of 1994. The duration of coastal residence for Southern Right Whales at the Head of Bight can potentially last up to 162 days, with whales recorded arriving as early as 10 May and leaving as late as 18 June in 1993, although on average the season extends for approximately 120 days (Burnell & Bryden in press). Coastal and Offshore Islands (or Reefs) − Nil. Rivers and Estuaries − Nil. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL AND PHYSICAL FEATURES − Southern Right Whales are presently considered both `endangered' (under the Commonwealth Endangered Species Act 1992) and `vulnerable to extinction' (by the World Conservation Union, and the International Union for the Conservation of Nature). Recently, the species has been proposed as `vulnerable’ under the Cetacean Action Plan for Australian Cetaceans (Bannister et al. in press). Estimates currently put the world population of Southern Right Whales at around 1500 to 3,000 individuals, with an Australian population of approximately 600-800 (Bannister et al. in press). Major populations are also recorded off South Africa and South America. The populations off South Australia and at the Head of Bight have shown no apparent increase (Ling & Needham 1991, Bannister et al. in press). While the species is presently recovering, the suspected very low diversity of the gene pool in the population (after being hunted to near extinction), has made the species particularly vulnerable to catastrophic collapses, such as from the effects of human activities or environmental changes. − The Great Australian Bight Marine Park protects the largest and densest breeding aggregation of Southern Right Whales in Australia, and one of the two major breeding and calving areas for this species in the world. As such, it has been identified as a major step in assisting the global recovery of this endangered and vulnerable species (see Southern Right Whale Recovery Plan, National Cetacean Action Plan). 1.1 Biological - − The Great Australian Bight region is becoming recognised world-wide as a significant critical seasonal habitat for populations of the endangered Southern Right Whale (Eubalaena australis). Within the Great Australian Bight region, the breeding and calving aggregation or nursery area at the Head of Bight is the largest, densest and most consistent aggregation in Australia (representing one of the two major breeding and calving areas for this species in the world). Every year, between the months of May and November, approximately 50-60 whales visit the Head of Bight region to calve, nurse their young and breed. The coastline from the Head of Bight to the West Australian border is used consistently, with many lactating females following the coastline west for varying distances during the latter part of their coastal residence season before turning south (Burnell, pers.comm.). Currently, breeding and calving aggregations are restricted to western South Australia, and Western Australia along the shores of the Great Australian Bight to Cape Leeuwin, with peak abundances in areas such as the Head of Great Australian Bight and Israelite Bay. Along the western and central southern coast of Australia there appears to be some preference by calving females for shallow north-east trending bays over sandy bottoms, with animals occurring in a narrow band, generally no more than 1 km from the shoreline (Bannister et al. 1996). Over recent years this aggregation of Southern Right Whales at the Head of Bight has been the largest, densest and most consistent aggregation and nursery area in Australia, producing approximately one-third of the observed total number of right whale born in Australian coastal waters each year (Bannister Page 17 EYRE REGION – NULLARBOR BIOUNIT − pups (under 12 months) were recorded, while in 1995, 90 pups (under 6 months of age), were recorded, of which 44 were still in lanugo (Dennis & Shaughnessy 1996). Breeding events were recorded at one colony over three seasons and were consistent with an eighteen month breeding cycle. At one colony the number of pups recorded from the cliff-edge in August 1994 was doubled when a subsequent count was made by entering the colony. Blue, Sperm, Minke (Balaenoptera acutorostrata) and Humpback Whales are reasonably commonly sighted, aswell as stranding around the Great Australian Bight. Possibly resident cetaceans are the Beaked Whale, Killer Whales (Orcinus orca) and Risso’s Dolphin (Grampus griseus). Individuals of tropical species such as Bryde’s Whale (Balaenoptera edeni) are occassionally seen in South Australian waters, and it has been suggested that they have travelled on the warm Leeuwin Current (Kemper & Ling 1991). Bottlenose Dolphins (Tursiops truncatus) have been seen on many occasions playing amongst Southern Right Whale groups (Ling & Needham 1988, Bannister 1993). − Two species of seals or pinnipeds are found in the Great Australian Bight region: the rare Australian Sea Lion (Neophoca cinerea) and the New Zealand Fur Seal (Arctocephalos forsteri) (Edyvane & Andrews 1995). In particular, the region contains many small breeding colonies of the Australian Sea Lion and as such, is becoming increasingly recognised as area of global conservation significance for this species. The Australian populations of the New Zealand Fur Seal are limited in their distribution to the Great Australian Bight, extending from the islands of Recherche Archipelago (WA), eastwards to Kangaroo Island (SA). − Recent systematic surveys of potential seal haul-out sites along the coastline of the Great Australian Bight, from Twin Rocks to Wilson’s Bluff (ie. a coastal distance of 206 km) have identified a total of approximately 280 Australian sea lions and 12 New Zealand fur seals (Dennis & Shaughnessy 1996). In 1994, a total of 289 Australian sea lions were recorded at 23 sites widely dispersed at the base of the Bunda Cliffs, while in 1995, a total of 284 sea lions were recorded at 10 sites. (Dennis & Shaughnessy 1996). Of these sites, 9 occurred in South Australia, and 1 occurred in Western Australia (2km west of Twilight Cove). Overall, a total of 10 breeding sites and 14 haul out sites were identified for the region. A total of 12 New Zealand Fur Seals were recorded for the same area of coast. Australian sea lions were found hauled-out on perched platforms formed by collapsed sections of the cliff at various levels above the sea. In 1994, a large colony of 37 sea lions were recorded in a deep cave accessed from the sea. In 1994 a total of 86 − By extrapolating from the number of sea lion pups found in the 1994 survey, the population of the Great Australian Bight region in South Australia has been estimated at between 613 and 744, which represents approximately 9.3% of the South Australian population or 6.6% of the total world population for this species (Dennis & Shaughnessy 1996). The significance of the populations of Australian sea lions in the Great calves Australian Bight is further increased because it is very likely that the populations were never commercially harvested - like many other populations along the southern coasts and islands of Australia last century. Generally, to the point of extinction. This is principally because of the isolation and general inaccessibility of the Great Australian Bight coast, both, from land and sea. Thus the populations have remained intact, providing probably one of the greatest sources of genetic diversity for this species in the world, and also, a very important genetic and geographic bridging population between the South Australian and Western Australian sea lion populations (Dennis & Shaughnessy 1996). The warm waters of the Great Australian Bight are also characterised by a unique `tropical' or Indo-Pacific element both, in the demersal and pelagic fauna (Maxwell & Cresswell 1981). Among the benthic invertebrate fauna, many of the echinoderm species recorded from South Australia originate from the Indo-Pacific region (Maxwell & Cresswell 1981). For instance, some 20 of the 84 species of hydroid recorded from South Australia have their principal distribution in the warm waters of the IndoMalay region. Other echinoderms of IndoPacific origin include the Basket Star (Euryale aspera), and the holothurians, Pentacta anceps and Pentacta quadrangularis (Maxwell & Cresswell 1981). Page 18 EYRE REGION – NULLARBOR BIOUNIT − The warm water of the Leeuwin Current is also responsible for the dispersal of pelagic marine organisms from waters north-west of Australia to the southern seaboard (Maxwell & Cresswell 1981). Tropical pelagic species, such as the Oriental Bonito and the Southern Bluefin Tuna move with the Leeuwin Current in their migration from the spawning grounds in the Java Sea. These same warm equatorial waters are also thought to be responsible for the significant tropical element in the phytoand zooplankton of the Great Australian Bight (Markina 1976) and the suspected relic tropical assemblage in the marine flora (ie. Sargassum spp.). − The influence of the Leeuwin Current is also reflected in the Holocene sediments of the Eucla Shelf, which are characterised by a lack of bryozoans, and an abundance of coralline algae and the large foraminifer, Marginopora (James et al. 1994). − Very little information on seabirds has been collected in the Great Australian Bight, particularly feeding and nesting aggregations. While breeding colonies of Little Penguins (Eudytula minor) are known to occur at the base of the Nullarbor Cliffs in the region, many seabird species, such as Short-tailed Shearwater (Puffinus tunuirostris) and Whitefaced Storm Petrel (Pelangodroma marina), probably feed in the area and/or breed wholly or largely on the offshore islands of the Great Australian Bight (Copley 1996). Other species which may frequent the Great Australian Bight include the Black-faced Shag, Eastern Reef Egret, Cape Barren Goose, White-bellied Sea-eagle, Sooty Oystercatcher, Pacific Gull, Fairy Tern, Crested Tern, Rock Parrot, and the Fleshy-footed Shearwater (Smith Island) (Eckert et al. 1985). Nonbreeding migratory seabirds such as Albatrosses, Petrels and Prions are known to frequent the coastal and shelf regions of the Great Australian Bight, but to an unknown degree (Copley 1996). Other species breed on more protected, inshore islands along the coast. 1.2 Physical − The Leeuwin Current: a major eastern boundary current system off the west coast of Australia. This warm, low salinity current originates from the tropical Indian Ocean and during winter from May to SeptemberOctober, flows south along the shelf break of the west coast, along the southern coast of Australia, to the eastern Great Australian Bight (to approximately 130oE). − For coastal and offshore fisheries, the Leeuwin Current is intimately linked to the population dynamics of many of Western Australia's and to a lesser extent, South Australia's, commercially important species (Lenanton et al. 1991). As such, the life history characteristics, such as spawning, migration, recruitment and feeding patterns, and ultimately the overall production, of many species along the western and southern seaboard of Australia have evolved under the influence of such a current system. Almost all of the major economically important fish stocks off the western and southern coasts of Western Australia are influenced to some extent by the Leeuwin Current (Lenanton et al. 1991). − Some pelagic species use the Leeuwin Current to disperse from the north-western waters of Australia to the southern seaboard of Australia. For instance, the Southern Bluefin Tuna (Thunnus maccoyii) spawns in the Java Sea and migrates southward along the western Australian coastline and eastward along the southern coast of Australia. It is an important commercial species and its distribution and abundance is influenced by the seasonality, strength and timing of the Leeuwin Current. Other commercial pelagic fish whose distribution and abundance is affected by the Leeuwin Current include, Mackerel (Scomber australasicus), Horse Mackerel (Trachurus declivis), Australian Salmon (Arripis truttaceus), and Australian Herring (Arripis georgianus). Southern Bluefin Tuna and the latter two species are particularly important fisheries in South Australian waters (Cappo 1987, Jones 1991). Page 19 EYRE REGION – NULLARBOR BIOUNIT − In South Australia, the Leeuwin Current also brings warm waters to the Head of the Great Australian Bight. Since cetaceans are generally born with little blubber, this is thought to explain the existence of several critical breeding areas for the endangered Southern Right Whale in this region. The warm Leeuwin current has also been suggested as a mechanism for bringing occasional individuals of tropical species such as Bryde's Whale into South Australian waters (Kemper & Ling 1991). − Merdayerrah sandpatch: Pleistocene wave cut platforms which indicate two previous sealevel events. The site is a recognised "geological monument" and is considered important for research into Quaternary sedimentation and sea-level history. 2 OTHER VALUES 2.1 Commercial Fisheries Southern Rock Lobster Most of the present fishing activity for Southern Rock Lobster (Jasus edwardsii) is confined to the eastern sector of this biounit, along rocky reefs east of Twin Rocks (ie. Fishing Zone 3, see Wahgunyah Biounit). While fishing activity has increased within this area in recent years, particularly in 1993/94, fishing activity has traditionally been minimal and opportunistic, with effort and catch rates representing a small proportion of the total effort and total catch of Southern Rock Lobster for the Northern Zone. Abalone No Blacklip Abalone or Greenlip Abalone is presently commercially harvested within this biounit. Based on the area of reefal habitat available for reef-associated species, existing and potential demersal fishing grounds for species, such as Blacklip Abalone and Southern Rock Lobster are likely to be limited within the Nullarbor Cliffs Biounit (Edyvane & Andrews 1996). Marine Scale Fishery During 1995/96 and 1996/97, 7 and 9 commercial licence holders, respectively (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) took marine scalefish from the waters between the Western Australian-South Australian border and the Head of Bight (ie. Fishing Zones 1 and 2). License holders expended approximately 51 and 50 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. Large mesh gill netting (>15cm mesh) was by far the most important method of capture, followed by handlines and rod and line (Jones 1991). The main species taken in inshore (<50m) waters were Gummy (Mustellus antarcticus) and Bronze Whaler (Charcharinus brachyurus) sharks, Sweep (Scorpus aquepinnis), Mulloway (Argyrosomus hololepidotus) and Australian Salmon (Arripis truttaceus), and in offshore waters, School Shark (Galeorhinus galeus), Ocean Leatherjackets (Nelusetta ayraudi) and Deep Sea Trevalla (Hyperoglyphe antartica) (Jones 1991). This fishery also includes such species as Pilchards, Whiting, Tommy Ruff, and Redfish. Records indicate that pregnant School Sharks move from south-eastern Australia to the Great Australian Bight for the period of gestation, and then return eastwards to give birth (Walker et al. 1989). The marine scalefish catch for this region (ie. Fishing Zones 1 and 2), represented less than 70 tonnes in 1995/96 and 34 tonnes 1996/97(or 0.33% and 0.24% of the total catch for the marine scalefish fishery in South Australian waters). Increases in shark and marine scalefish catches in recent years (ie. since 1991/92) with the Great Australian Bight region, are not apparent. The majority of this catch (90%+) is made up of Shark. Large mesh gill netting (>15cm) was by far the most important method of capture (Jones 1991). Extensive pilchard fisheries occur in bays to the west of the Great Australian Bight (Esperance, Albany, WA), whilst in SA, operations target areas east of the Bight. In 1992/93, the total allowable catch (TAC) for the pilchard fishery (3,450 tonnes) constituted half of the SA’s commercial marine scale fishery. Page 20 EYRE REGION – NULLARBOR BIOUNIT Deep Sea Trawl Fishery The Great Australian Bight trawl fishery is a Commonwealth managed fishery which extends from Kangaroo island off South Australia, to Cape Leeuwin in Western Australia, a distance of over 2 000 km. The southern boundary of the Great Australian Bight Trawl Fishery is the edge of the Australian Fishing Zone (AFZ) which extends to 200 nautical miles offshore. The northern boundary (31.52oS) mostly follows the 200m depth contour about 20-90 nautical miles offshore. Fishing activity in the Great Australian Bight Trawl fishery is currently confined to a fairly narrow margin off the continental shelf and slope, in depths of less than 1 200 m, mostly within the 100200 m depth zone (BRS 1993). Data from the Great Australian Bight Trawl Fishery Logbook database indicate that species caught at depths less than 200m (ie. the continental shelf) comprise mostly Deepwater Flathead (Neoplatycephalus conatus) and Bight Redfish (Centroberyx gerrardi), while at depths greater than 200m (ie. the continental slope), Orange Roughy and various Oreo Dories (family Oreosomatidae) are the main species. The slope fishery has contacted in recent years and in 1994, yielded the lowest catch on record (BRS 1994). Bight (Jones 1991). Prior to this, effort was more evenly spread throughout the waters of the Great Australian Bight. The reason for the contraction of the fishing area has been output controls in the fishery through quota restrictions (Jones 1991). This fishery operates outside the limits of the South Australian jurisdictional waters (ie. seaward of 3nm). With the shift away from longline fishing to purse seining, most fish are now taken south, below 32o00’S and east of the Great Australian Bight. Prior to 1990/91, catches in this region varied from less than 1% to 18% of the annual South Australian catch - with the vast majority of the catch being taken west of 130o55’E. 2.2 Mariculture There are no aquaculture activities in this region at present. The Far West Aquaculture Management Plan (Ashman 1996) has recommended no aquaculture development within this region: Nullarbor Policy Area − This fishery is outside State waters (ie. 3nm). Southern Bluefin Tuna The Southern Bluefin Tuna (Thunnas maccoyii) fishery is a Commonwealth managed fishery. Southern Bluefin Tuna spawn between September to March, in the warm waters of the Indian Ocean, south of Indonesia. After spawning the tuna move south along the western seaboard of Australia, and easterly along the south coast of the Australian continent, where juvenile fish of 1 to 4 years of age school seasonally in the surface waters off southern Australia. Southern Bluefin Tuna usually become available to the Western Australian fishery at approximately 1-2 years of age, and at approximately 2 years of age for the South Australian fishery. The fish are generally fished by Japanese longliners when approximately 4 years of age. Southern Bluefin Tuna mature at approximately 8 years of age and may live as long as 40 years (BRS 1995). Young tuna tend to stay in relatively shallow waters associated with coasts and continental shelves. However, once they reach maturity, they move to deeper oceanic waters and live a pelagic existence. Because of their long exposure to fishing activity prior to spawning, the species is highly vulnerable to overfishing, and then slow to recover. Nullarbor Policy Area (all state jurisdictional waters from the WA border, east to Point Fowler) – zoned for protection of conservation and wilderness values and existing fisheries use. Licenses will not be considered for aquaculture development in this zone. 2.3 Recreation and Tourism Fishing − Great Australian Bight: shoreline fishing. Major species: Australian Salmon and Mulloway. Average catch rates for Australian Salmon in this area in 1986/87 were the highest of any area in the State. Tourism − There is an increasing demand for `whale watching' tours to the Head of the Bight. Tourists view the Southern Right Whales during May to November from the edge of the cliffs. − The coastline from the West Australian border to the Head of Bight has many lookouts that take advantage of the spectacular views. In recent years an active purse seine and pole fishery for this species has been confined to the South Australian sector of the Great Australian Page 21 EYRE REGION – NULLARBOR BIOUNIT 2.4 Scientific Research and Education − Researchers from the South Australian Museum and University of Sydney conduct regular surveys of Southern Right Whales in the Great Australian Bight region. − In recent years, scientific research at the Head of Bight has greatly enhanced our understanding of the reproductive biology and behaviour of Southern Right Whales (see Burnell & Bryden in press). The area at the Head of Bight represents one of the few areas in the world where the breeding and general behaviour of the Southern Right Whales can be observed closely by researchers (and the public). The proximity of the whales to shore and the unique cliff-top views represents one of the best areas in the world where the breeding, calving and general behaviour of Southern Right Whales can be observed and studied by scientific researchers. Because of the absence of human interference in the area, these scientific studies are highly important in revealing the `natural' behaviour patterns of the whales. For the same reason, the area also affords some of best whale-watching views in the world. − Agriculture/Industry − − − Nullarbor National Park (588,300 ha). − The Nullarbor National Park protects part of the world's largest semi-arid karst (limestone) landscapes. The park encompasses 593 000 ha and is a vast area of low open woodland; the treeless karst plain comprising a portion of the park. The principal vegetation communities consist of mallee and dry land tea-tree, with an area of saltbush and bluebush communities. There is no management plan in place for this area and at present, no management planning process has being undertaken. Yalata Aboriginal Land Lease (456,000 ha), adjacent to the Head of Bight. 2.6 Significant Cultural and Historical Features Aboriginal − Yalata Aboriginal Land. The Yalata Aboriginal Land Lease is held in trust for the Yalata Council by the Aboriginal Lands Trust of South Australia. The Yalata lands cover a total of 456,000 ha stretching from Coorabie in the east to the Head of Bight in the west. This portion of land abuts the Great Australian Bight Marine Park immediately adjacent to the critical breeding and calving areas at the Head of Bight. European 2.5 Adjacent Land Use • Urban Centres None. Other Uses Fisheries research in this area includes, regular catch and effort monitoring of the major State and Commonwealth commercial fisheries in the region and also, oceanographic research in the Head of the Bight. National and Conservation Parks Apart form tracks and roads, there is no development along this biounit. Spur roads from the Eyre Highway provide access to a number of scenic points. Tracks parallel to the coast enable 4WD vehicles to reach most other parts of the biounit. − None. 3 CURRENT CONSERVATION STATUS OF THE NULLARBOR BIOUNIT − Marine Parks Great Australian Bight Marine Park (129o 132oE, 3 nautical miles offshore), comprising: − Marine Sanctuary Great Australian Bight Marine Park Whale Sanctuary (43,587 ha) National Park − Great Australian Bight Marine National Park (124,732 ha) Page 22 EYRE REGION – NULLARBOR BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE NULLARBOR BIOUNIT Great Australian Bight (offshore) − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, ecosystem protection (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human induced change), biogeographic (distinct biogeographic/oceanographic region), ecological (deepwater bryozoan-sponge communities, Leeuwin Current contributes to essential ecological processes, deepwater canyons), economic (shark and deepwater flathead breeding areas, deep water), social, international significance (global importance for marine mammals, cetaceans, White Shark, squid), practicality (compatibility-adjacent to Great Australian Bight Marine Park–State waters ). Page 23 EYRE REGION – WAHGUNYAH BIOUNIT II MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE WAHGUNYAH BIOUNIT This biounit extends from the Head of Bight to Cape Adieu and covers an area of 195,381ha and a coastal distance of 122 km. It faces southwest into the Great Australian Bight. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY Moderate to high wave energy. 2 GEOLOGY AND COASTAL GEOMORPHOLOGY4 Apart from the Nullarbor Cliffs, the orientation, form and evolution of the Holocene shoreline is generally uniform, consisting of Holocene barrier deposits, usually backed by moderate to extensive episodic transgressive barriers. The Yalata sand dunes at the Head of the Bight extend more than 7km inland and form the largest active transgressive dune system in the biounit. Low cliffs or shore platforms and reefs consisting of Pleistocene dune calcarenite outcrop extensively along the coast. Nuyts Reef consists of three main clusters of rocks which form a roughly triangular pattern, the northern part of which is an elongate rocky outcrop of crystalline basement. 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly sandy beaches, and some limestone rocky shores. − Of the total inshore subtidal habitats mapped in the biounit (29,693ha), sandy habitats comprise 27,971 ha (94.5%), and limestone reefs comprise 1,722 ha (5.8%). No seagrass habitats have been recorded in this region. 4 The coastal nearshore marine habitats of this biounit comprise mostly sand out to at least 2-3km, interspersed with small narrow patches of low profile limestone reef (Edyvane & Baker 1996, Edyvane & Andrews 1996). West of the Head of Bight (130o30’E to 129o00’E), reefal habitat is mainly confined to within 0-100m of the coastal cliffs of the Nullarbor, the rest of the habitat, seaward of the coastal reef, comprising sand, out to 2-3km. However, narrow sections of limestone reef, ie. irregular patch reefs, do occur further offshore in the western Nullarbor region, near the Merdayerrah Sandpatch (129o30’E to 129o00’ East), but sandy habitat is by far the dominant habitat. Major Benthic Communities • Macroalgal − The marine benthic habitats of this region within the Great Australian Bight has been the subject of few studies. Biological surveys conducted by researchers from SARDI in June 1994 indicate subtidal benthic communities assemblages in the region are typical of warm to cool temperate waters, and high swell wave conditions. On the rocky reefs within the Great Australian Bight Marine Park, subtidal macroalgal communities are dominated by the kelp, Ecklonia radiata and the fucoid Scytothalia dorycarpa (Edyvane & Andrews 1996), and articulated (eg. Amphiroa sp.) and encrusting coralline algae. Of particular interest is the presence of a suspected relic tropical assemblage in the macroflora, indicated by the presence of an undescribed fucoid, Sargassum spp. No seagrass communities have been recorded within this biounit. From Eyre Coast Protection District Study Report. Page 24 EYRE REGION – WAHGUNYAH BIOUNIT Coastal and Offshore Islands (or Reefs) 2 − D'Entrecasteaux Reef. 2.1 Commercial Fisheries − Yatala Reef. − Rivers and Estuaries None. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL AND PHYSICAL FEATURES 1.1 Biological − Critical breeding and calving area for the Southern Right Whale (Eubalaena australis): Head of the Bight, Twilight Cove and Merdayerrah (see Section 1.1, Nullarbor Biounit). Whales are also often seen moving along the coast towards the Head of Bight. − The Great Australian Bight region is best known for its large cetaceans (see Section 1.1, Nullarbor Biounit). − Tropical element in the fauna and flora of the Great Australian Bight (see Section 1.1, Nullarbor Biounit). − D'Entrecasteaux Reef is a haul out site for Australian Sea Lions. A total of 20 sea lions were recorded on this reef in 1977 (Robinson & Dennis 1988). 1.2 Physical − The Leeuwin Current: see under Nullarbor Biounit (see Section 1.1, Nullarbor Biounit). − The Yalata sand dunes at the Head of the Bight extend more than 7 km inland and form the largest active transgression dune system along the Eyre Coast. OTHER VALUES Southern Rock Lobster Most of the present fishing activity for Southern Rock Lobster (Jasus edwardsii) in this region is confined to the rocky reefs east of Twin Rocks (ie. Fishing Zone 3). While fishing activity has increased within this area in recent years, particularly in 1993/94, fishing activity has traditionally been minimal and opportunistic, with effort and catch rates representing a small proportion of the total effort and total catch of Southern Rock Lobster for the Northern Zone. In 1995/96 and 1996/97 a total of 7 and 6 licensed operators fished in this area (ie. Fishing Zone 3), catching approximately 21,138 and 6,756 kg of lobsters, respectively (or 0.41% and 0.13% of the total catch for Southern Rock Lobster in South Australian waters). Abalone Limited Blacklip Abalone and Greenlip Abalone is presently commercially harvested within this biounit (i.e. MapCode 1D, D’Entrecasteaux Reef region), but due to the confidentiality constraints these figures are not available. Based on the area of reefal habitat available for reef-associated species, existing and potential demersal fishing grounds for species, such as Blacklip Abalone and Southern Rock Lobster are likely to be limited within the Wahgunyah Biounit (Edyvane & Andrews 1996). Marine Scalefish Fisheries The same commercial fin fisheries operate in this biounit as for the Nullarbor Biounit. During 1995/96 and 1996/97, 7 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) took marine scalefish from the waters between the Head of Bight and west of Cape Adieu (ie. Fishing Zone 3). Page 25 EYRE REGION – WAHGUNYAH BIOUNIT License holders expended approximately 75 and 24 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 3), represented 53,263 kg in 1995/96 and 16,209 kg in 1996/97(or 0.51% and 0.16% of the total catch for the marine scalefish fishery in South Australian waters). Increases in shark and marine scalefish catches in recent years (ie. since 1991/92) with the Great Australian Bight region, are not apparent. The majority of this catch (90%+) is made up of Shark. Large mesh gill netting (>15cm) was by far the most important method of capture (Jones 1991). 2.5 Adjacent Land Use National and Conservation Parks − 2.2 Mariculture There are no aquaculture activities in this region at present. The Far West Aquaculture Management Plan (Ashman 1996) has recommended no aquaculture development within this region: Nullarbor Policy Area − Nullarbor Policy Area (all state jurisdictional waters from the WA border, east to Point Fowler) – zoned for protection of conservation and wilderness values and existing fisheries use. Licenses will not be considered for aquaculture development in this zone. Agriculture/Industry Apart form tracks and roads, there is no development along this biounit. Spur roads from the Eyre Highway provide access to a number of scenic points. Tracks parallel to the coast enable 4WD's to reach most other parts of the biounit. Urban Centres − 2.3 Recreation and Tourism Fishing − The same recreational fisheries operate in this biounit as for the Nullarbor Biounit. There is an increasing demand for `whale watching' tours to the Head of Bight. Tourists view the Southern Right Whales during May to November from the edge of the cliffs. 2.4 Scientific Research and Education − Researchers from the South Australian Museum and University of Sydney, conduct regular surveys of Southern Right Whales in the Great Australian Bight region (see Section 2.4, Nullarbor Biounit). − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region and also, oceanographic research in the Head of the Bight. None. Other Uses − Yalata Aboriginal Land, adjacent to the Head of Bight. 2.6 Significant Cultural and Historical Features Tourism − Wahgunyah Conservation Reserve (38,280 ha). Very little resource information is available on this section of the land abutting the eastern end of the Marine Park. The Wahgunyah Conservation Reserve is designated a Conservation Reserve under the Crown Lands Act. The area is presently managed by the regional South Australian National Parks and Wildlife office of the Department of Environment and Natural Resources (DENR). There is no management plan in place for this area and at present, no management planning process has being undertaken. Aboriginal − Yalata Aboriginal Land. European • Shipwrecks − Little is known of shipwrecks on the west coast of South Australia. There are records of 3 shipwrecks in this region. Only one is older than 75 years and is a vessel of unknown description recorded as being east of Twin Rocks in Edward John Eyre’s journal on 4 March 1841. Page 26 EYRE REGION – WAHGUNYAH BIOUNIT 3 − CURRENT CONSERVATION STATUS OF THE WAHGUNYAH BIOUNIT Marine Reserves None − Marine Parks Great Australian Bight Marine Park (129o 132oE, 3 nautical miles offshore), comprising: − Marine Sanctuary Great Australian Bight Marine Park Whale Sanctuary (43,587 ha) − National Park Great Australian Bight Marine National Park (124,732 ha) − 4 Netting Closures None AREAS OF HIGH CONSERVATION VALUE IN THE WAHGUNYAH BIOUNIT Great Australian Bight (offshore) − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, ecosystem protection (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human induced change), biogeographic (distinct biogeographic/oceanographic region), ecological (deepwater bryozoan-sponge communities, Leeuwin Current contributes to essential ecological processes, deepwater canyons), economic (shark and deepwater flathead breeding areas, deep water), social, international significance (global importance for marine mammals, cetaceans, White Shark, squid), practicality (compatibility-adjacent to Great Australian Bight Marine Park–State waters ). Page 27 EYRE REGION – FOWLERS BIOUNIT III MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE FOWLERS BIOUNIT This biounit extends from Cape Adieu to Point James, and covers an area of 146,486ha. southwesterly direction into the Great Australian Bight. MARINE BIOGEOGRAPHY 1 Major Benthic Communities • Macroalgal − Exposed limestone shores and reefs in this region (eg. Cape Adieu, Nuyts Reef, Cape Nuyts, Point Bell) are dominated by Ecklonia radiata and Scytothalia dorycarpa, with species of Cystophora (C.moniliformis, C.grevillea, C.platylobium, C.racemosa) as sub-dominants. In the sheltered areas, reefs tend to be dominated by the red algae, Osmundaria prolifera, Amansia pinnatifida and species of Sargassum (S.heteromorphum, S.spinuligerum) and Scaberia agardhii as subdominants. • Seagrass − With this exposed region, seagrass communities occur in the sheltered lee of headlands (eg. Point Fowler, Point Sinclair and Point Bell). Large meadows of Posidonia (P.sinuosa, P.angustifolia) and Amphibolis (A.antarctica, A.griffithii) occur in Fowlers Bay, while smaller meadows occur in Bell and Sinclair bays. BIOLOGY • Coastal and Offshore Islands (or Reefs) Major Inshore Habitats − Nuyts Reef (south of Cape Adieu). Major intertidal habitats in the region include mostly limestone cliffs, and some sandy beaches. − Sinclair Island. − Major Rivers/Estuaries None. OCEANOGRAPHY This biounit experiences wave energies ranging from low in the bays, to high around the offshore islands and cliffs. 2 GEOLOGY AND GEOMORPHOLOGY5 COASTAL The majority of the coast within this biounit comprises Pleistocene dune calcarenite cliffs interspersed with Holocene sediments. Precambrian crystalline rock forms the bedrock of all major peninsulas, all islands (excepting Eyre Island and Nuyts Archipelago) and most headlands, thereby providing the primary crenulations along the coast, and acting as a basement for the multiple episodes of Pleistocene marine - aeolian transgressions. The biounit is moderately crenulate with numerous bays and embayments usually containing Holocene sediments, separated by headlands and sections of Pleistocene cliffs. 3 − − 5 It faces in a Of the total inshore subtidal habitats mapped in the biounit (26,439 ha), limestone reefs comprise 21,666 ha (81.9%), sandy bottoms comprise 3,134 ha (11.9%), and seagrass meadows comprise 1,639 ha (6.2%). From Eyre Coast Protection District Study Report. Page 28 EYRE REGION – FOWLERS BIOUNIT MARINE CONSERVATION VALUES 1.2 Physical Geological Monuments 1 SIGNIFICANT BIOLOGICAL AND PHYSICAL FEATURES − Clare Bay: raised beach with wave cut shore platforms and lithified beach deposit. − Point Le Hunte (by Point Sinclair): Pleistocene Bridgewater Formation. 2 OTHER VALUES 1.1 Biological The Great Australian Bight region is best known for its large cetaceans. At least 17 species of cetaceans have been recorded in this region, some of which are migratory species, such as Blue Whales, Sperm Whales, Minke Whales, Humpbacks, Rorquals, as well as the Southern Right Whale (Kemper & Ling 1991). Killer Whales have also been recorded and their presence is probably related to the abundance of pinnipeds along the western Eyre Peninsula. Critical area for the Southern Right Whale (Eubalaena australis). Whales are also often seen moving along the coast towards the Head of Bight. Groups of as many as five whales have been seen from the air near Fowlers Bay and pairs or singletons are now fairly common sights as they move from bay to bay around the western side of Eyre Peninsula (Watt & Ling 1985). They probably mate, give birth and suckle inshore. − − Nuyts Reef Conservation Park. This cluster of rocks and reefs represents a significant haul out site for New Zealand Fur Seals (Shaughnessy 1990) and a haul out and breeding site for Australian Sea Lions (Robinson & Heard 1985, Gales et al. 1994). Western and Middle Nuyts Reefs have been identified as breeding sites for sea lions, while Southern Nuyts Rock and Eastern Nuyts Reef appear to be haul out sites only (Gales et al. 1994). Colony number has been estimated at 207 (ie. 43 pups) at Western Nuyts Reef and 207 (ie. 43 pups) at Middle Reef (Gales et al. 1994). Sea lion colony numbers vary from 60-120 recorded in 1977 (Robinson & Dennis 1988) to a total of 216 sea lions recorded in 1990 (Gales et al. 1994). Fur seals haul out at Southern Nuyts Rock and Western Nuyts Reef (Shaughnessy et al. 1994). A total of 37 fur seals were recorded in 1990 (Shaughnessy 1990). The park is on the Register of the National Estate. 2.1 Commercial Fisheries Major single species fisheries in this region include Western King Prawn, Abalone and Southern Rock Lobster. There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand line. Some netting occurs inside parts of Venus Bay. Some of the Southern Bluefin Tuna boats use Thevenard as their major port of landing. Southern Rock Lobster In 1995/96 and 1996/97 a total of 10 and 11 licensed operators fished in this area (ie. Fishing Zone 7), catching approximately 49,122 and 32,461 kg of lobsters, respectively (or 0.961% and 0.64% of the total catch for Southern Rock Lobster in South Australian waters). Abalone Blacklip Abalone and Greenlip Abalone is presently commercially harvested within this biounit. (ie. MapCode 1A-E, Cape Adieu to Point Bell region), but due to confidentiality constraints these figures are not available. Marine Scalefish Fisheries During 1995/96 and 1996/97, 14 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from this region (ie. Fishing Zone 7). Sinclair Island Conservation Park provides a resting place for Australian Sea Lions (Watt & Ling 1985, Robinson & Heard 1985, Gales et al. 1994), New Zealand Fur Seals (Shaugnessy 1990) and Crested Terns. The park is on the Register of the National Estate. Page 29 EYRE REGION – FOWLERS BIOUNIT License holders expended approximately 190 and 280 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 7) represented 23 ,972 kg in 1995/96 and 112,894 kg in 1996/97(or 0.23% and 1.11% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Fowlers Bay: 1 restricted marine scalefish. − Ceduna: 6 restricted marine scalefish licenses, 12 unrestricted marine scalefish, 1 Western King Prawn. − Smoky Bay: 5 unrestricted marine scalefish licenses. − Streaky Bay and Haslam: 3 restricted marine scalefish licenses, 28 unrestricted marine scalefish, 3 Abalone licenses, 2 Southern Rock Lobster. Thevenard: 4 restricted marine scalefish licenses, 32 unrestricted marine scalefish, 3 Southern Rock Lobster, 1 Western King Prawn. − − Baird Bay: 2 unrestricted marine scalefish licenses. − Port Kenny: 12 unrestricted marine scalefish licenses, 1 restricted marine scalefish, 1 Western King Prawn. − Venus Bay: 3 unrestricted marine scalefish licenses. 2.2 Mariculture There is presently one R&D aquaculture lease in this region at Fowlers Bay. The Far West Aquaculture Management Plan (Ashman 1996) has recommended limited aquaculture development within this region: − 2.3 Recreation and Tourism Fishing − − − Fowlers Bay Zone (defined waters within Fowlers Bay) – zoned for potential aquaculture development and protection of conservation and fisheries values. Licenses will be considered for a maximum of 40 ha of aquaculture development in this zone, after 2 years of R&D. Scott Bay: beach fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon and Mulloway. Fowlers Bay, Point Fowler: jetty and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Sweep, Garfish, Yellowtail Kingfish, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. Clare Bay: beach fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Mulloway, Snook, Sweep, Blue Groper, Tommy Rough, Trevally, Toothbrush Leatherjacket and Silver Drummer. Tourism The many bays and spectacular coastal scenery of this biounit are strong tourist attractions in this region. Major activities include boating, fishing and swimming. − Rocky Point, Point James: camping, SCUBA diving. − Cactus Beach is 21 km south of Penong (east of Ceduna), and is considered as one of the best surfing beaches in the world. Although the surrounding land is privately owned, camping is allowed by permission of the owner. Fowlers Policy Area − Point Le Hunte Zone (defined waters on eastern side of Point Sinclair) - zoned for potential aquaculture development and protection of conservation and fisheries values. Licenses will be considered for a maximum of 10 ha of aquaculture development in this zone, after 2 years of R&D. 2.4 Scientific Research and Education − Researchers from the NPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies in the Nuyts Archipelago region. Page 30 EYRE REGION – FOWLERS BIOUNIT − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of South Rock Lobster field stocks. 2.5 Adjacent Land Use National and Conservation Parks − Nuyts Reef Conservation Park (29 ha). − Sinclair Island Conservation Park (1 ha). − Fowlers Bay Conservation Reserve (8,649ha). − Chadinga Conservation Reserve (8,125 ha). − Point Bell Conservation Reserve (602 ha). Agriculture/Industry Most of the adjacent land is used for agriculture. There are no major industries along the coast. − The region between Fowler's Bay and Streaky Bay is also culturally significant for the dominance of `natural' Aboriginal fishtraps in this region (Martin 1988). These fishtraps used modified natural features such as rock platform reef formations, tidal pools and shellgrit ridges. None of these types of traps have been recorded elsewhere along the west coast of Eyre Peninsula. Within this biounit, natural Aboriginal fish traps have been found at: − Rocky Point (1). The Murat Bay Aquaculture Management Plan (Bond T. 1991) reports the following areas of Aboriginal significance in this biounit6: − − − Urban Centres None. 2.6 Significant Cultural and Historical Features The rocky coast of the Point James Zone has Aboriginal sites of high sensitivity and moderate significance, whilst the sandy coast has Aboriginal sites considered to be of moderate sensitivity and low significance (Nicholson 1990). European Old whaling station at Fowler's Bay. Shipwrecks There are records of 7 shipwrecks in this region. None of these are protected under Commonwealth legislation. The two oldest wrecks are the `Spindrift’ (lost in 1927) and the `Cecelia’ (lost in 1946), both near Point Le Hunte. Aboriginal The region encompassed within Murat Bioregion (and Fowlers Biounit) represents one of the most significant regions of Aboriginal heritage along the whole of the Eyre Province (A. Nicholson pers.comm.). The remoteness of the region has resulted in many sites remaining completely undisturbed by European activities. Nicholson (1991), in a survey of cultural sites from Fowlers Bay to Elliston, identified the following occupation site within this biounit, as being particularly significant: − Point Brown 4 (approximately 400-500 years old): a recent occupation complex consisting of middens and an artefact manufacturing site. To be recommended for National Estate listing (Nicholson pers.comm.). 3 CURRENT CONSERVATION STATUS OF THE FOWLERS BIOUNIT − Marine Reserves None. − Marine Parks None Netting Closures − Fowlers Bay (all waters west of a line from First Point to a point 200 metres north east of the end of the jetty and then generally westward to a point on the mainland 200 metres north of the jetty). 6 "Sensitivity" refers to the quantity of sites in a particular region: the more sites there are in a region, the more "sensitive" it is thought to be. "Significance" refers to the quality or importance of sites within a given region and is defined according to certain criteria such as significance to the archaeological discipline or to the Aboriginal community. Page 31 EYRE REGION – FOWLERS BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE FOWLER BIOUNIT Nuyts Reef- D’Entrecasteux Reef − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, research (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (breeding site for Australian sea-lion, haul out site for New Zealand Fur Seals), economic (Greenlip Abalone, Blacklip Abalone, marine scalefish fisheries, Southern Rock Lobster), scientific (scientific research/monitoringAustralian Sea Lions), national (Register of the National Estate–Nuyts Reef Conservation Park), practicality (insulation, compatibilityadjacent to Nuyts Reef Conservation Park). social values, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), economic (Greenlip Abalone, Blacklip Abalone, marine scalefish fisheries, Southern Rock Lobster), social (aboriginal fish traps at Rocky Point, recreation, camping, diving), national (potential for listing on the Register of the National Estate), practicality (accessibility). Fowlers Bay-Clare Bay − Primary IUCN Conservation Values: biodiversity, cultural, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (geological monument at Clare Bay, representative habitats), ecological (seagrass meadows at Fowlers Bay whale resting site, ecological integrity), economic (Greenlip Abalone, Blacklip Abalone, marine scalefish fisheries, Southern Rock Lobster), social (old whaling station, recreation, tourism, aesthetic values), practicality (accessibility, compatibility-adjacent to Fowlers Bay Conservation Reserve). Sinclair Island – Point Le Hunte − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, cultural values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monument – Point Le Hunte, representative habitats), ecological (breeding site – Crested Terns, haul out site for Australian sea-lions and New Zealand Fur Seals, whale resting site), economic (Greenlip Abalone, Blacklip Abalone, marine scalefish fisheries, Southern Rock Lobster), social (shipwrecks - `Sprindrift’, `Cecelia’, recreation, aesthetic values), national (Register of the National Estate – Sinclair Island Conservation Park), practicality (accessibility, compatibilityadjacent to Sinclair Island Conservation Park). Rocky Point − Primary IUCN Conservation Values: cultural, Page 32 EYRE REGION – STREAKY AND NUYTS BIOUNIT IV MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE STREAKY AND NUYTS BIOUNIT This coastal region is represented by 2 biounits: the inshore Streaky Biounit (the seaward boundary defined by the 30 metre coastal bathymetric contour), and an offshore Nuyts Bioregion (which extends down to 50 metre contour. The Streaky Biounit extends from Point James to Cape Bauer, and covers an area of 190,949ha. The Nuyts Bioreregion encompasses the Nuyts Archipelago, and covers an area of 283,165ha. The region faces in a southwesterly direction into the Great Australian Bight. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY These biounits experience wave energies ranging from low in the bays, to high around the offshore islands and cliffs. 2 GEOLOGY AND GEOMORPHOLOGY7 COASTAL The majority of the coast within thes biounits comprise Pleistocene dune calcarenite cliffs interspersed with Holocene sediments. Precambrian crystalline rock forms the bedrock of all major peninsulas, all islands (excepting Eyre Island and Nuyts Archipelago) and most headlands, thereby providing the primary crenulations along the coast, and acting as a basement for the multiple episodes of Pleistocene marine - aeolian transgressions. The Streaky Biounit is highly crenulate with numerous bays and embayments usually containing Holocene sediments, separated by headlands and sections of Pleistocene cliffs. There are three large coastal embayments within the inshore Streaky Biounit (Tourville Bay, Bosanquet Bay, Decres Bay, Smoky Bay and Streaky Bay) and numerous offshore islands within the offshore Nuyts Biounit, including the Nuyts Archipelago, Lacy Islands, Evans Island and Flinders Reef, and the Isles of St. Francis. The Nuyts Archipelago group of islands consists of Purdie Island (the largest) and a number of small islands and reefs, all of crystalline basement. Only Purdie Island has a cover of calcareous aeolianite. Lounds Island is an elongate outcrop of crystalline basement. 7 Lacy Islands consist of Lacy Island (the largest) and several smaller islands. Lacy Island is crystalline basement with a cover of calcareous aeolianite, Bridgewater Formation which forms a prominent platform at the base of the island. The smaller islands appear to be wholly crystalline basement (Kinsman 1973). Evans Island is crystalline basement covered by a thick, fairly flat blanket of aeolianite. The basement forms a platform around the whole island and several rocky outcrops just offshore. Flinders Reef consists of two small islands of crystalline basement. The Isles of St. Francis consist of six major islands and several smaller islands. The larger islands are Egg, Dog, West, St. Francis, Masillon and Fenelon Islands. Egg island is crystalline basement covered by calcareous aeolianite which forms a broad platform around the entire island. An unnamed island south of Egg Island is also aeolianite on crystalline basement. Dog Island is crystalline basement with a cover of calcareous aeolianite, as is an unnamed island to the north-east of Dog Island. West Island is crystalline basement with a limited cover of aeolianite. St. Francis Island is the largest island in the group and is crystalline basement covered with a thick layer of aeolianite. In several areas, beaches are formed in embayments. Masillon and Fenelon Islands are similar, with crystalline basement outcrops at the base of each island and a thick cover of aeolianite, with one small embayment. Hart Island is an elongate outcrop of crystalline basement, but there is no aeolianite. Cannan Reefs, approximately 7km south-west of Fenelon Island, are wholly crystalline rocks. Yatala Reef and Goat Island are both crystalline basement, with Goat Island also having a thick cover of aeolianite. Franklin Island is virtually two islands joined superficially by a sand bar but is most probably underlain by crystalline basement; as is the remainder of the island and the small islands nearby. From Eyre Coast Protection District Study Report. Page 33 EYRE REGION – STREAKY AND NUYTS BIOUNIT Caulerpa Cactoides. Franklin Island has a thick cover of calcareous aeolianite covered by low vegetation, with recent sands forming narrow beaches on the northern side (Kinsman 1973). 3 BIOLOGY Major Inshore Habitats − − Major intertidal habitats in the region include bays and `estuaries’ (ie. mangroves, saltmarshes, mudflats), offshore islands, sandy beaches and limestone rocky shores. Of the total inshore subtidal habitats mapped in the Streaky Biounit (110,972ha), seagrass meadows comprise 86,163ha (77.6%), sandy bottoms comprise 22,466ha (20.2%), and limestone reefs comprise 2,343ha (2.1%). Of the total inshore subtidal habitats mapped in the Nuyts Biounit (2,711ha), limestone reefs comprise 2,483 (91.6%), seagrass meadows comprise 144ha (5.3%), sandy bottoms comprise 84ha (3.1%). Major Benthic Communities • Macroalgal − Rocky limestone shores and reefs vary from wave exposed), to sheltered, in the lee of islands and headlands, and also, along coasts protected by the Nuyts Archipelago. Along exposed coasts (eg. Point Brown, Cape de Mole, Cape Bauer), reefs are dominated by Ecklonia radiata and Scytothalia dorycarpa and articulated (Amphiroa, Metagoniolithon) and encrusting corallines, with species of Cystophora (eg. C.racemosa) as subdominants. On moderately exposed coasts (eg. Cape D’Estrees), reefs are dominated by species of Sargassum (S.lacerifolium and S.spinuligerum, S.heteromorphum, S.decipiens, S.verruculosum, S.paradoxum), with Cystophora monilifera, Caulocystis ulvifera, and Osmundaria prolifera, as subdominants. • Seagrass − Large seagrass dominated embayments occur in this region (ie. Tourville, Murat, Bosanquet, Decres and Smoky bays) and also, adjacent to Eyre and St Peter Islands. Many species of seagrass occur in this area, and meadows are typically dominated by species of Posidonia (P.australis, P.sinuosa), and Heterozostera tasmanica in shallower regions. The seagrass Halophila australis typically occurs as a subdominant, sometimes with the green alga, Coastal and Offshore Islands (or Reefs) These biounits are characterised by many coastal and offshore islands. Many of them have a variety of habitats including sandy beaches, seagrass meadows and algal assemblages and rocky shores. On the islands themselves, large bird colonies or colonies of the New Zealand Fur Seal or the Australian Sea Lion are often present. These are detailed below. • Nuyts Archipelago, comprising: − − Purdie, Purdie Rocks, Lounds Island, Lacy, Evans, Goat, St Peter, Eyre Islands • Flinders Reef − Franklin Islands: South Franklin Rocks, small South Franklin Island, Franklin Island, small NE Franklin Island − St. Francis Isles: Freeling, Smooth, Egg, Dog, West, St. Francis, Masillon, Fenelon and Hart Islands • Cannon Reefs • Eba Island • Pigface Island • Olive Islands Major Rivers/Estuaries Because of the arid nature of this region, all the estuaries in the Streaky Biounit are not `true' estuaries but rather `reverse estuaries'. However, since they exhibit typical estuarine flora and fauna, they are considered as `estuarine habitats'. − − − − − − − − Tourville Bay. Murat Bay. Denial Bay. Bosanquet Bay. Smoky Bay. Blanche Port (Streaky Bay). Laura Bay. Acraman Creek. Page 34 EYRE REGION – STREAKY AND NUYTS BIOUNIT 19 waterbirds have been recorded for the bay, 11 of these are listed under international treaties (Fuhlbohm 1992). White-bellied Sea Eagles and Ospreys breed in nearby cliffs. Approximately 3,500-5,000 waders utilise the area (Eckert 1974). Streaky Bay has been identified as an area of international importance for shorebirds by Watkins (1993). MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND 1.1 Biological Coastal and Marine Wetlands of National Importance − − Tourville Bay (Davenport Creek) has been identified as a wetland of national importance (see ANCA 1996). The mangroves in this bay represent not only the western-most extent of mangroves (Avicennia marina) in South Australia, but also, the largest stand of mangrove forest on Eyre Peninsula. They also form the most extensive stand of mangroves between Spencer Gulf and Exmouth Gulf in Western Australia. The mangroves of Davenport Creek in particular, are growing on a more sandy substrate than is usual for South Australian mangroves. Most of the bay is less than 2m deep, and consists of intertidal sand/mud flats (42 km2); mangroves (13 km2); samphire; seagrass and reefs (Bucher & Saenger 1989). The estuary itself is a nursery area for fish and Western King Prawns and a feeding area for waders, and as such, it is one of the most important coastal wetlands in the state (Bond T., 1991). Tourville Bay was identified as an area of international importance for shorebirds by Watkins (1993). Threatened species include Hooded Plover, Thinornis rubricollis (Nv, Sv) and Eastern Curlew, Numenius madagascariensis (Sv). Breeding sites have been recorded for Pied Cormorants, Phalacrocorax varius, Grey Cormorants, P.carbo and White-faced Herons, Egretta novaehollandiae (Watkins 1993). In a review of estuaries in Australia, Bucher & Saenger (1989) identified Tourville Bay as one of three estuaries of outstanding conservation value in South Australia. Streaky Bay (including Acraman Creek) has been identified as a wetland of national importance (see ANCA 1996). The bay is a major waterbird feeding and roosting area for the west coast of South Australia, while Acraman Creek is one of the finest examples of diverse samphire vegetation on the Eyre Peninsula (ANCA 1996). Threatened plant species include Halosarcia flabelliformis (Nv, Sv) and Centrolepis cephaloformis (Sr) at Acraman Creek. Threatened fauna include Hooded Plover, Thinornis rubricollis (Nv, Sv). White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Osprey, Pandion haliaetus (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv) and Eastern Curlew, Numenius madagascariensis (Sv). A total of − Both Smoky Bay and Streaky Bay estuaries support substantial areas of marine wetlands (ie. mangroves, seagrass) that would provide habitat for estuarine and offshore fish stocks. Smoky Bay consists of intertidal sand/mud flats (10.54 km2 - with Heterozostera tasmanica); mangroves (7.62 km2); and very dense sand 1m high with samphire and patches of low Sarcocornia (Bucher & Saenger 1989). Blanche Port (Streaky Bay): consists of intertidal sand/mud flats (7.19 km2); mangroves (3.42 km2); and scattered areas of Sarcocornia within the mangroves (Butler et al. 1975). The size of the estuaries and the extent and diversity of their associated wetlands suggest that they contribute significantly to the ecology of the local area (Bucher & Saenger 1989). Smoky Bay particularly is an important nursery area for fish and Western King Prawns. The oyster zone was found to be the only area to have abundant juvenile Western King Prawns in Smoky Bay (Wallner 1985). The mangroves in the north of the zone are a substantial stand but not significant locally. Other Areas of Significance − Murat, Denial and Bosanquet Bays support substantial areas of wetland that would provide habitat for estuarine and offshore fish stocks. Murat Bay has extensive beds of razor shells in the bay. Seagrass is the dominant marine vegetation with brown algae on limestone reef areas. Denial Bay has scattered stands of mangroves and seagrasses that dominate vegetation in sandy areas, with brown algae on the reefs. The marine environment is an important nursery area for Western King Prawns and fish especially the area from the jetty to Low Point (Wallner 1985). Bosanquet Bay consists of seagrass, reef areas and a small stand of mangroves in the northwest corner of the bay. The shallow sandy coast of the northern shore of the bay is important as a nursery area for Western King Prawns (Wallner 1985). Page 35 EYRE REGION – STREAKY AND NUYTS BIOUNIT The size of the estuaries and the extent and diversity of their associated wetlands suggest that they would contribute significantly to the ecology of the local area. − Wittelbee Conservation Park: on the Register of the National Estate. − Laura Bay Conservation Park: sandflats are an important feeding area for waders. The island off Dog Fence Point is also an important roosting area for cormorants and gulls. Laura Bay itself is a sheltered bay with an extensive sand dune system and is reknown as an area of outstanding scenic qualities. Fox Creek is a small tidal creek that flows from the park into Laura Bay and is lined with mangroves and saltmarsh. Several different coastal environments have been conserved within the park. The park is on the Register of the National Estate. Extensive Seagrass Meadows − The seagrasses in the Streaky Biounit represent the largest areas of seagrass on the Eyre Coast. The sheltered embayments of the Eyre Coast, particularly Streaky and Smoky Bay (ie. Streaky Biounit), and Port Douglas (ie. Douglas Biounit), support extensive seagrass meadows. These extensive seagrass meadows flourish in shallow clear waters, generally in waters less than 15m, and provide the basis for the significant productivity of the coastal regions in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 86,163 ha in Streaky and Smoky Bay, and 8,567 ha in Port Douglas. Together, the seagrasses of the Eyre Coast represent approximately 15% (ie. 1407 km2) of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Inshore Islands of Conservation Value − St Peter Island: high conservation value. The sand banks surrounding the island are important Western King Prawn nursery areas and rare shell fish have been recorded here. The mangrove, sand bank and seagrass environments around the island are important fish nursery areas. Brush-tailed Bettongs and Stick Nest Rats have been re-introduced to the island. − Eyre Islands: Eyre Island, Little Eyre Island, Goalen Rocks, and Cape Missiessy. The vegetation on these islands is completely undisturbed. Eyre Island and Cape Missiessy in particular have significant samphire and mangrove cover. Around the islands and coast, seagrass meadows dominate. The sand banks north of Eyre Island and east of Cape Missiessy are important Western King Prawn nursery areas (Wallner 1985). − Eba Island Conservation Park is connected to the mainland by a long sand bar. The park is on the Register of the National Estate. − Pigface Island Conservation Park has a breeding colony of Little Black Cormorant (Phalacrocorax sulcirostris). The park is on the Register of the National Estate. Offshore Islands of Conservation Value − The offshore islands in the Nuyts Biounit represent significant breeding sites for the rare Australian Sea Lion (Neophoca cinerea) and haul out sites for the New Zealand Fur Seal (Arctocephalus forsteri) in South Australia. The islands of the Nuyts Archipelago are particularly important as breeding sites for Australian Sea Lions. Significant breeding colonies occur on Purdie Island (120 pups, estimated population 577), Lounds Island (26 pups, estimated population 125), West Island (30 pups, estimated population 144), Fenelon Island (50 pups, estimated population 241), Small NE Franklin Island (50 pups, estimated population 241), Small South Franklin Island (75 pups, estimated population 361), Olive Island (50 pups, estimated population 241), and Jones Island (5 pups, estimated population 24) (Robinson & Heard 1985, Gales et al. 1994). Haul out sites also occur on Sinclair, Hart, Purdie, Egg, Smooth, Dog, Freeling, Masillon, South Franklin Rocks, Lacy and Evans islands (Watts & Ling 1985, Gales et al. 1994). New Zealand Fur Seals also haul out on Fenelon, Lacy and Hart Islands (Shaughnessy et al. 1994). Page 36 EYRE REGION – STREAKY AND NUYTS BIOUNIT − Nuyts Archipelago Conservation Park includes a wide variety of habitats and limestone capped islands on massive granite bases. Apart from the relatively pristine environment, the most significant thing about this island group is the presence on the Franklin Islands of the last known population in the world of Greater Stick-nest Rats (Leporillus conditor). Because of its importance to conservation, Franklin Island has been proclaimed a Prohibited Area. This island also supports a subspecies of Southern Brown Bandicoot. Most of the other islands have large Short-tailed Shearwater breeding colonies in the summer months. Many of these islands also support significant breeding colonies or haul out sites for rare Australian Sea Lions and to a lesser extent New Zealand Fur Seals (see above). The mangroves present on St Peter Island are the only oceanic stand on the entire South Australian coast. Goat and Franklin islands have dense populations of very large Black Tiger Snakes. − The park is on the Register of the National Estate. − Isles of St Francis Conservation Park: comprises St Francis, Dog, Smooth, Egg, West, Masillon, Fenelon and Hart Islands. St Francis is home to an enormous breeding population of Short-tailed Shearwaters, a population of Island Bandicoots (Isoodon obesulus) and a variety of reptiles, including an important population of Carpet Python. There is also a program to reintroduce Brushtailed Bettongs on the island. The other islands of the St Francis Group are much less disturbed than the main island and are biologically interesting in their own right. Many of the islands are breeding colonies or haul out sites for Australian Sea Lions (see above). A breeding colony of New Zealand Fur Seals is also present on Fenelon Island. Extensive seagrass meadows and algal assemblages also occur around the islands, together with abundant fish fauna including Blue Groper. The park is on the Register of the National Estate. Populations of native bush rats occur on Dog Island, Masillon Island, Lacy Island, and Goat Island. − Olive Islands Conservation Park, off Cape Bauer. The park is home to a breeding colony of more than 150 Australian Sea Lions (Watts & Ling 1985). The park is on the Register of the National Estate. − The Great Australian Bight region is best known for its large cetaceans. At least 17 species of cetaceans have been recorded in this region, some of which are migratory species, such as Blue Whales, Sperm Whales, Minke Whales, Humpbacks, Rorquals, as well as the Southern Right Whale (Kemper & Ling). Killer Whales have also been recorded and their presence is probably related to the abundance of pinnipeds along the western Eyre Peninsula. − Critical area for the Southern Right Whale (Eubalaena australis). Whales are also often seen moving along the coast towards the Head of Bight. Groups of as many as five whales have been seen from the air near Fowlers Bay and pairs or singletons are now fairly common sights as they move from bay to bay around the western side of Eyre Peninsula (Watt & Ling 1985). They probably mate, give birth and suckle inshore. 1.2 Physical Geological Monuments − Laura Bay: Holocene beach ridge system. At Laura Bay a Holocene beach ridge system has prograded 1,200m into the bay with considerable variation occurring in the spacing and height of the beach ridges. Although the beach ridge system to some degree reflects the local conditions of the embayment, it also reflects the conditions (whether changes in storminess or sea-level) that have determined the rates and episodes of Holocene sedimentation along the western portion of the Eyre coast. − Eyre Island: Holocene beach - foredune ridge systems. Eyre Island evolved during the Holocene as a series of multiple beach foredune ridges that prograded simultaneously on 3 fronts with extensive samphire and mangrove flats between the prograding arms. The island represents an island in the making and preserves a rich history of sea-levels and sedimentation during the Holocene. − Point Brown: dykes on the wave-cut platform. Page 37 EYRE REGION – STREAKY AND NUYTS BIOUNIT Point Collinson (northern Streaky Bay): Pleistocene wave-cut platform. At Point Collinson a Pleistocene wave-cut platform 1.0m above MSL is overlain by two small coqioma remnants 0.4-0.6m thick. One of these contains intact bivalves, including Anadara spp. The site provides evidence of previous sea-level events. In 1995/96 and 1996/97 a total of 17 and 13 licensed operators fished in the Streaky Biounit (ie. Fishing Zone 10), catching approximately 11,710 and 12,171 kg of lobsters, respectively (or 0.23% and 0.24% of the total catch for Southern Rock Lobster in South Australian waters). − Acraman Creek: stranded tidal creek system. Five kilometres west of Acraman Creek a tidal creek system has been cut off from the sea by a prograding recurved spit. The stranded creek system is well preserved and readily accessible by vehicle, making it an excellent research site. − The barrier-spit sequence is also well preserved and provides a record of sedimentation over the Holocene period. 2 OTHER VALUES Blacklip Abalone and Greenlip Abalone is presently a significant fishery within the Nuyts Biounit. In 1994/95 and 1995/96 a total of 20,670 and 15,807 kg of Greenlip was harvested within this region (ie. MapCode 2A-H, 2J, 3C-D, Nuyts Archipelago region, Franklin Islands), and represented 9.1% and 7.0% of the total Greenlip Western Zone catch (or 5.49% and 4.22% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 21243 and 16611 kg of Blacklip was harvested within this region, and represented 6.8% and 6.0% of the total Blacklip Western Zone catch (or 4.30% and 3.59% of the total catch for Blacklip in South Australian waters). − 2.1 Commercial Fisheries Major single species fisheries in this region include Western King Prawn, Abalone and Southern Rock Lobster. There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand line. Some netting occurs inside parts of Venus Bay. Some of the Southern Bluefin Tuna boats use Thevenard as their major port of landing. Western King Prawn This biounit is located within the waters of the West Coast prawn fishery, which comprises 3 license holders (ie. Boats). All vessels fish within the waters of this biounit (ie. Fishing Zones 8), the Newland Biounit (ie. Fishing Zone 15) and the Douglas Biounit (ie. Fishing Zone 27). In 1995/96 and 1996/97 a total of 200,764 and 166,414 kg was caught for this fishery, with a total effort of 3,144 and 2,778 hours, respectively (or 8.84% and 8.22% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster Abalone The Blacklip Abalone and Greenlip Abalone is considerably less within the waters of the Streaky Biounit. (ie. MapCode 3A, Smoky Bay, Cape Missiessy – Point Collinson region), and represented 0.1% and 0.8% of the total Greenlip Western Zone catch (or 0.06% and 0.50% of the total catch for Greenlip in South Australian waters), but due to confidentiality constraints these figures are not available. Marine Scalefish Fisheries During 1995/96 and 1996/97, 19 and 21 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Nuyts Biounit (ie. Fishing Zone 8), respectively. License holders expended approximately 1,141 and 1,334 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 8) represented 173,574 kg in 1995/96 and 196,644 kg in 1996/97(or 1.67% and 1.94% of the total catch for the marine scalefish fishery in South Australian waters). In 1995/96 and 1996/97 a total of 19 and 18 licensed operators fished in the Nuyts Biounit (ie. Fishing Zone 8), catching approximately 54,832 and 43,345 kg of lobsters, respectively (or 1.07% and 0.85% of the total catch for Southern Rock Lobster in South Australian waters). Page 38 EYRE REGION – STREAKY AND NUYTS BIOUNIT During 1995/96 and 1996/97, 26 and 28 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Streaky Biounit (ie. Fishing Zone 10), respectively. License holders expended approximately 1929 and 2,043 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 10) represented 64,455 kg in 1995/96 and 73,702 kg in 1996/97(or 0.62% and 0.73% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Fowlers Bay: 1 restricted marine scalefish. − Ceduna: 6 restricted marine scalefish licenses, 12 unrestricted marine scalefish, 1 Western King Prawn. − Smoky Bay: 5 unrestricted marine scalefish licenses. Streaky Bay and Haslam: 3 restricted marine scalefish licenses, 28 unrestricted marine scalefish, 3 Abalone licenses, 2 Southern Rock Lobster. − − Thevenard: 4 restricted marine scalefish licenses, 32 unrestricted marine scalefish, 3 Southern Rock Lobster, 1 Western King Prawn. − Baird Bay: 2 unrestricted marine scalefish licenses. − Port Kenny: 12 unrestricted marine scalefish licenses, 1 restricted marine scalefish, 1 Western King Prawn. − Venus Bay: 3 unrestricted marine scalefish licenses. Ceduna Policy Area − Denial Bay Aquaculture Zone (waters of Denial Bay, west to Cape Beaufort) – zoned for sustainability of existing oyster culture industry. Licenses will be considered for a maximum of 122ha of oyster culture within this zone. − Smoky Bay Aquaculture Zone (southern waters of Streaky Bay) – zoned for sustainability of existing oyster culture industry. Licenses will be considered for a maximum of 85ha of oyster culture within this zone. − Tourville Bay Zone (waters at the mouth of Tourville Bay) – zoned to assess potential aquaculture (oyster fattening). Licenses will be considered for maximum of 2ha of R&D oyster culture. − Murat Bay Zone (waters of Murat Bay) zoned for assess potential aquaculture (oyster fattening). Licenses will be considered for maximum of 2ha of R&D oyster culture. − St Peter Island Zone (waters off southeastern end of island) - zoned to assess potential aquaculture (oyster fattening). Licenses will be considered for maximum of 2ha of R&D oyster culture. − D’Ecres Bay Zone (waters of D’Ecres Bay, from Cape Vivonne to Cape D’Estres, excluding waters adjacent Wittlebee Conservation Park) – zoned for aquaculture development. Licenses will be considered for a maximum of 40ha of aquaculture development. − Waterwitch Zone (waters of Smoky Bay, excluding waters adjacent to Laura Bay and Laura Bay Conservation Park) - zoned for aquaculture development. Licenses will be considered for a maximum of 80ha of aquaculture development. − Licenses will not be considered for aquaculture developments outside these zones, including Purdie Islands, St Francis Isles, Franklin Islands. 2.2 Mariculture Pacific Oyster farming is the major mariculture industry in this coastal biounit. At present this region represents one of the major regions for oyster growing in South Australia. As such, significant activity is present in Denial Bay (116 of leases), western Blanche Port (or Streaky Bay) and eastern Smoky Bay. The Far West Aquaculture Management Plan (Ashman 1996) has recommended consolidation of the existing oyster industry within this region: Page 39 EYRE REGION – STREAKY AND NUYTS BIOUNIT 2.3 Recreation and Tourism − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of South Rock Lobster field stocks. − Islands in the St Francis Group (St Francis, Egg, Masillon, and Fenelon) have been the site of a number of marine and terrestrial ecological studies by both, fisheries researchers and researchers from the SA Museum and research institutions (see Shepherd & Womersley 1976). Fishing − − Ceduna: jetty, boat and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Groper, Tommy Rough, Trevally and Southern Calamari. Smoky Bay, Point Brown: boat, jetty and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Sweep, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket and Southern Calamari. 2.5 Adjacent Land Use − − Streaky Bay, Back Beach: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Greenback Flounder, Blue Swimming Crab, Tommy Rough, Trevally, Toothbrush Leatherjacket and Southern Calamari. National and Conservation Parks − Nuyts Archipelago Conservation Park (5483 ha): includes all remaining offshore islands between Rocky Point and Point Brown, with the exception of St Peters Island which is held under a Pastoral Lease, and Evans Island which is a lighthouse Reserve managed by the Commonwealth Government. − Isles of St Francis Conservation Park (1,320 ha): comprises St Francis, Dog, Smooth, Egg, West, Masillon, Fenelon and Hart Islands. − Wittelbee Conservation Park (153 ha). − Laura Bay Conservation Park (267 ha). − Acraman Creek Conservation Park (3,960ha). − Caratoola Recreation Park (53 ha). − Eba Island Conservation Park (121 ha). − Pigface Island Conservation Park (10 ha). − Olive Islands Conservation Park (21 ha). There is an artificial reef located in Streaky Bay (consisting of 100 rubber tyre modules). Tourism The many bays and spectacular coastal scenery of this biounit are strong tourist attractions in this region. Major activities include boating, fishing and swimming. − Davenport Beach: swimming. − Ceduna: watersports, swimming, visiting Oyster Farms. Fishing or touring trips run to the local bays, as well as 4WD or helicopter tours along the coast. 2.4 Scientific Research and Education − Researchers from the NPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies in the Nuyts Archipelago region. Regular counts of the Point Labatt colony have been made since 1966 (Robinson & Heard 1985). Agriculture/Industry Most of the adjacent land is used for agriculture. There are no major industries along the coast. The jetty at Thevenard is the principal port on the West Coast for shipping grain, gypsum and salt. The Yatala Channel provides access to the jetty and is dredged and maintained by the Department of Marine and Harbours. International ships frequent this port. Page 40 EYRE REGION – STREAKY AND NUYTS BIOUNIT Urban Centres − Ceduna (population 2,877). − Streaky Bay (population 992). 2.6 Significant Cultural and Historical Features Aboriginal The region encompassed within the Murat Bioregion (and Nuyts Biounit) represents one of the most significant regions of Aboriginal heritage along the whole of the Eyre Province (A. Nicholson pers.comm.). The remoteness of the region has resulted in many sites remaining completely undisturbed by European activities. Nicholson (1991), in a survey of cultural sites from Fowlers Bay to Elliston, identified the following occupation sites as being particularly significant: − − Acraman Creek 4 (approximately 6,700 years old): a discrete occupation site consisting of four middens. To be recommended for National Estate listing (Nicholson pers.comm.). − Natural Aboriginal fish traps have been found at Rocky Point (1), Tourville Bay (2), Murat Bay (10), Halfway Camp, in Murat Bay (1), Point Dillon-Cape Missiessy (1), Smoky Bay (1), and Eba Island (1) (Martin 1988). − `Constructed' Aboriginal fishtraps, consisting of woven wooden traps, have been recorded at Duckponds Creek, in Murat Bay (1) and on the north coast of St Peter Island (1) (Martin 1988). The Murat Bay Aquaculture Management Plan (Bond. T, 1991) reports the following areas of Aboriginal significance in this region8: − The rocky coast of the Point James Zone has Aboriginal sites of high sensitivity and moderate significance, whilst the sandy coast has Aboriginal sites considered to be of moderate sensitivity and low significance (Nicholson 1990). − The rocky coast occupied by Ceduna and Thevenard probably had Aboriginal sites of high sensitivity and moderate significance, but unfortunately most of this area is now highly developed and the sites disturbed (Nicholson 1990). − Aboriginal sites along Cape Beaufort are considered to be of high sensitivity and moderate significance (Nicholson 1990). − The rocky coast of the Waterwitch Aquaculture Zone has Aboriginal sites of high sensitivity and moderate significance; the sandy coast has sites of high sensitivity and low significance. The beach east of Wittlebee Point and the southern part of Smoky Bay have sites of moderate sensitivity and significance. Corvisart Bay 3, Granites (approximately 67,000 years old): a discrete occupation site consisting of three middens. To be recommended for National Estate listing (Nicholson pers.comm.). In addition to these outstanding sites a number of other occupation sites of cultural significance have also been identified by Nicholson (1991): − The region between Fowler's Bay and Streaky Bay is also culturally significant for the dominance of `natural' Aboriginal fishtraps in this region (Martin 1988). These fishtraps used modified natural features such as rock platform reef formations, tidal pools and shellgrit ridges. None of these types of traps have been recorded elsewhere along the west coast of Eyre Peninsula. Tourville Bay 7, Nadir Landing: a discrete occupation site: an artefact or stone scatter. One of the ten largest occupation sites in the Eyre Province. Tourville Bay as a region is considered to be of moderate Aboriginal significance and sensitivity, however the rocky coast within the bay is considered to be of high sensitivity and moderate significance (Nicholson 1990). − Perlubie 2, near Eba Island: a discrete occupation site 20 m from MHWM: an artefact or stone scatter. One of the ten largest occupation sites in the Eyre Province. − Corvisart 7, Yanerbie sandpatch: a discrete occupation site consisting of cultural, animal bones. 8 "Sensitivity" refers to the quantity of sites in a particular region: the more sites there are in a region, the more "sensitive" it is thought to be. "Significance" refers to the quality or importance of sites within a given region and is defined according to certain criteria such as significance to the archaeological discipline or to the Aboriginal community. Page 41 EYRE REGION – STREAKY AND NUYTS BIOUNIT − The rocky coast of the Wittlebee Zone has Aboriginal sites of high sensitivity and moderate significance. 4 − In Laura Bay, sites of high sensitivity and moderate significance occur on rocky coast, while sites of moderate sensitivity and significance in sandy areas. 4.1 Streaky Biounit Tourville Bay − European − The shipwreck of `Eleni K' (1966) lies in 10m of water, 1.5 km north of Goat Island. 3 CURRENT CONSERVATION STATUS OF THE STREAKY AND NUYTS BIOUNITS 3.1 Streaky Biounit − Marine Reserves None. − Marine Parks None. − Netting Closures Denial and Smoky Bays (all waters east of a line from Point Brown to Point James) Streaky Bay − − 3.2 Nuyts Biounit Marine Reserves None. − Marine Parks None. − Netting Closures None. Prime IUCN Conservation Values: biodiversity, cultural, social values (IUCN Category IA). IUCN IUCN Identification Criteria: naturalness (not subject to humaninduced change), biogeographic (representative habitats), ecological (mangroves and wetlands at Tourville Baylargest stand on Eyre Peninsula, threatened waterbirds – Hooded Plover, Eastern Curlew, breeding sites – Pied Cormorants, Grey Cormorant, White-faced Heron, ecological integrity), economic (nursery area for economic species-Western King Prawn, marine scalefish, crustaceans), social (aboriginal fish traps at Rocky Point, Tourville Bay, aboriginal occupation site at Tourville Bay, recreation, tourism), national/international (Wetland of National Significance, international importance for shorebirds), practicality (accessibility, insulation). Decres Bay (all waters east of a line from Point de Mole to Cape Bauer, Wandoma) − AREAS OF HIGH CONSERVATION VALUE IN THE STREAKY AND NUYTS BIOUNITS Prime IUCN Conservation Values: social values, biodiversity, (IUCN III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative habitats), ecological (seagrass meadows), economic (marine scalefish fisheries), social (recreation), national (Register of the National Estate-Wittlebee Conservation Park), practicality (accessibility, insulation, compatibility-adjacent to Wittlebee Conservation Park). Laura Bay – Smoky Bay − Prime IUCN Conservation Values: biodiversity, cultural, social values (IUCN II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative habitats, geological monuments-Laura Bay), ecological (diversity of marine habitats, mangroves at Laura Bay, extensive seagrass meadows in Smoky Bay and Laura Bay, ecological integrity), economic (key nursery areas for Western King Prawn, marine scalefish fisheries), social (aboriginal fish traps at Point Dillon-Cape Missiessy, Smoky Bay, aesthetic values-Laura Bay), national Page 42 EYRE REGION – STREAKY AND NUYTS BIOUNIT (Register of the National Estate-Laura Bay Conservation Park), practicality (accessibility, insulation, compatibility-adjacent to Laura Bay Conservation Park). 4.2 Nuyts Biounit − Acraman Creek-Streaky Bay − Prime IUCN Conservation Values: biodiversity, cultural, social values (IUCN II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monuments at Point Brown, Point Collison, Acraman Creek, representative habitats), ecological (diversity of marine habitats, extensive seagrass meadows of Streaky Bay, samphire communities at Acraman Creek, threatened waterbirds – Hooded Plover, White-bellied Sea Eagle, Osprey, Cape Barren Goose, Eastern Curlew, ecological integrity), economic (key nursery areas for Western King Prawn, marine scalefish fisheries), social (aboriginal occupation complex at Point Brown, Acraman Creek, recreation), national/international (Wetland of National Importance – Streaky Bay, including Acraman Creek, international importance for shorebirds, aboriginal occupation complexes at Point Brown and Acraman Creek), practicality (accessibility, insulation, compatibility-adjacent to Acraman Creek Conservation Park). Nuyts Archipelago Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, aesthetics, scientific research/monitoring (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to humaninduced change), biogeographic (representative habitats), ecological (ecological integrity, diversity of marine habitats, mangroves on St Peter Island, significant breeding colonies for Australian Sea Lions – Purdie Rocks, Lounds Island, West Island, Fenelon Island, NE Franklin Island, Olive Islands and Jones, significant breeding colonies for New Zealand Fur Seals – Fenelon Island, breeding sites for Short-tailed Shearwaters, Little Penguins-St Francis Island, St Peter Island, nesting sites for Ospreys, White-bellied Sea Eagle-St Peter Island, Bandicoots, Carpet Python, Black Tiger Snakes), economic (Greenlip and Blacklip Abalone, Southern Rock Lobster), social (aesthetic values, aboriginal fish trap-St Peter Island, tourism, recreation), scientific (scientific studies at St Francis Isles), national (Register of the National Estate – Nuyts Archipelago Conservation Park, St Francis Conservation Park), practicality (insulation, compatibilityadjacent to Nuyts Archipelago Conservation Park, Isles of St Francis Conservation Park). Franklin Islands-Eyre Islands-Cape Missiessy Eba Island − Prime IUCN Conservation Values: cultural values, biodiversity (IUCN III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (extensive seagrass meadows, sandflats, breeding colony of Silvergulls), economic (marine scalefish fisheries, key nursery area for Western King Prawn and marine scalefish fisheries), social (aboriginal fish trap-Eba Island, aboriginal occupation site at Perlubie), national (Register of the National Estate-Eba Island Conservation Park), practicality (insulation, compatibility-adjacent to Eba Island Conservation Park). − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to humaninduced change), biogeographic (geological monument - Eyre Island, representative habitats), ecological (mangroves/samphires on Eyre Island and Cape Missiessy, seagrass meadows, significant breeding colony of Australian Sea Lions on NE Franklin Island, Greater Stick Nest Rats – last remaining population, Southern Brown Bandicoot, Black Tiger Snakes), economic (key nursery area for Western King Prawn, marine scalefish fisheries, Greenlip and Blacklip Abalone, Southern Rock Lobster), social (aboriginal fish traps at Point Dillon-Cape Missiessy), national/international (Register of the National Estate-Nuyts Archipelago Conservation Park, Greater Stick Nest Rats-Franklin Island), practicality (insulation, compatibility-adjacent to Franklin Islands Conservation Park, Eyre Islands Conservation Park). Page 43 EYRE REGION – STREAKY AND NUYTS BIOUNIT Olive Islands − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to humaninduced change), ecological (significant breeding colony of rare Australian Sea Lions), national (Register of the National Estate-Olive Islands Conservation Park), practicality (insulation, compatibility-adjacent to Olive Islands Conservation Park). Page 44 EYRE REGION - YANERBIE BIOUNIT V MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE YANERBIE BIOUNIT This biounit extends from Cape Bauer to Talia Caves, just south of Venus Bay and covers an area of 82,854 ha. MARINE BIOGEOGRAPHY 1 An estimated 57% of the average volume of bay is exchanged each tidal cycle (Bye 1993). OCEANOGRAPHY This biounit experiences wave energies ranging from very low in the coastal embayments (ie. Baird Bay, Venus Bay, to very high wave swell conditions along the mainland coast. Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperature of 14oC. The inshore coastal regions are very productive and are characterised by seasonal, nutrient-rich, coldwater upwellings, which can result in an offshore sea surface temperature gradient of 18oC to 11oC in inshore areas during the summer months (Wenju et al. 1990). There appears to be a relationship between the upwellings and the pilchard numbers in these areas (Ward & McLeay 1998). Venus Bay is a shallow semi-enclosed bay linked to the ocean via a narrow mouth. The depth at the mouth of the bay is approximately 6m. The main channel lies to the east of Germein Island. The bay consists of two almost level basins of about 2.6m and 2.3m depth (Bye 1993). An extensive shallow region occurs in the south-east of the bay, and a narrower shallow region along the northern shore. The restricted access to ocean (the entrance to Venus Bay is 140m across) imposes a physical barrier to the advection of King Western Prawn larvae into the bays (Wallner 1985, Carrick 1993). High net summer evaporation combined with long water residence times within the bay produces large salinity and temperature variability (Wallner 1985). Salinity increases from the mouth of Venus Bay (at 36 psu) to the shallow inshore regions (which reach salinities of 40 psu). Notable regions of high salinity occur in the far southeast, and in the northwest of the bay (Bye 1993). 2 GEOLOGY AND GEOMORPHOLOGY9 COASTAL The majority of the coast within this biounit comprises Pleistocene dune calcarenite cliffs interspersed with Holocene sediments. Precambrian crystalline rock forms the bedrock of all major peninsulas, thereby providing the primary crenulations along the coast, and acting as a basement for the multiple episodes of Pleistocene marine - aeolian transgressions. Around the Westall Peninsula the calcarenite mantles have been wave eroded to form shore platforms (Twidale et al. 1977). The shoreline consists of reefs and shore platforms, as well as beach-surf zone and surf zone. There are two large coastal embayments within this biounit (Baird Bay, Venus Bay). Venus Bay (73 km2) consists of areas of samphire swamps and mangroves (0.40 km2) together with intertidal sand/mudflats (14.74 km2). Germain Island is a large mangrove and samphire swamp built by the tidal currents in Venus Bay. 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include bays and `estuaries’ (ie. saltmarshes, mudflats), sandy beaches, rocky limestone shores, and offshore islands. − Of the total inshore subtidal habitats mapped in the biounit (21,977ha), sandy bottoms comprise 9,573 ha (43.6%), seagrass meadows comprise 6,602 ha (30.0%), and limestone reefs comprise 5,802 ha (26.4%). Venus Bay is a poorly flushed estuary, with an estimated flushing time of 75 days (Bye 1993). The flushing mechanism is primarily by tidal currents flowing in and out of mouth of the bay. 9 From Eyre Coast Protection District Study Report. Page 45 EYRE REGION - YANERBIE BIOUNIT Point Labatt near Streaky Bay conserves one of the largest mainland colony of Australian Sea Lions (Neophoca cinerea) in Australia (Gales et al. 1994). Major Benthic Communities • Macroalgal − Along the exposed rocky shores and reefs in this region (eg. Searcy Bay, Point Labatt, Point Weyland), subtidal rocky shore macroalgal communities are dominated by the fucoids, Cystophora monoliformis, C.siliquosa, and C.monolifera and the red algae, Osmundaria and Haliptilon occur in shallow waters (ie. 5m). In deeper waters, rocky reef communities are dominated by Ecklonia radiata and Acrocarpia paniculata with Osmundaria prolifera with species of Cystophora (C.platylobium, C.racemosa, C.moniliformis) as sub-dominants, and also a range of large understorey red algae (eg. Plocamium, Phacelocarpus, Carpophyllis, Carpopeltis, Peysonnelia, Sonderopelta) and green algae (Caulerpa flexilis, C.obscura). • Seagrass − Seagrass communities within the region are confined to Baird Bay and Venus Bay. Shallow water seagrass communities, dominated by Heterozostera tasmanica and Amphibolis antarctica, occur at the mouth of Venus Bay. Within the bay, seagrass communities dominated by Zostera muelleria, Posidonia australis and Ruppia occur (see Figure 2). − Numbers of sea lions at the colony have varied from 14 to 82 between 1966 and 1983 (Robinson & Heard 1985). A more recent survey recorded 42 sea lions (Gales et al. 1994). Threatened species include the Whitebellied Sea Eagle, Haliaeetus leucogaster (Sv), Osprey, Pandion haliaetus (Sv). An old Osprey nest is present on the northern most headland of the area. The most commonly seen seabirds include cormorants, gulls and terns. The park is on the Register of the National Estate. − Baird Bay is a recognised wetland of national importance (see ANCA 1996). Baird Bay is a narrow, shallow, sheltered bay that opens into Anxious Bay. The bay comprises extensive areas of tidal sand flats, beach ridges and coastal dunes and provides a drought refuge and habitat for a wide variety of waterbirds on the west coast of South Australia (ANCA 1996). The bay supports the largest concentration of Grey Plovers, Pluvialis squatarola on the west coast. The islands in the bay provide a roosting place for a large number of seabirds. Threatened species include White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Osprey, Pandion haliaetus (Sv), Fairy Tern, Sterna nereis (Sv). A total of 19 species of waterbirds have been recorded, 10 of which are listed under international treaties (Fuhlbohm 1992). Baird Bay has been identified as an area of international importance for shorebirds by Watkins (1993). − Jones Island (Baird Bay Islands Conservation Park) has a small breeding colony of Australian Sea Lions on its seaward slopes. A colony of 33 sea lions was recorded in 1990 (Gales 1990). It is also a known breeding area for Pelicans (Eckert et al. 1985). The park is on the Register of the National Estate. Coastal and Offshore Islands (or Reefs) − Venus Bay contains Germain, Garden and Tank islands, and three other small islands. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND 1.1 Biological Coastal and Marine Wetlands of National Importance − Point Labatt is a recognised wetland of national importance (see ANCA 1996) and also, the site of the Point Labatt Conservation Park and Aquatic Reserve. Page 46 EYRE REGION - YANERBIE BIOUNIT diversity of it's associated wetlands suggest that it's contribution to the ecology of the local area would be significant (Bucher & Saenger 1989). The reefs near the mouth of Venus Bay support high densities of juvenile Roei Abalone (Haliotis roei) (D.Mackie, PISA, pers.comm.). Other Areas of Conservation Significance − Venus Bay Conservation Park (1,460 ha) consists of Venus Bay Peninsula (Cape Weyland), Germain, Garden and Tank islands, and three other small islands. The park has small breeding populations of Pelicans (Pelicanus conspicillatus), while one island has been used as a `halfway house' to reintroduce captive-bred Brush-tailed Bettongs Bettongia penicillata to St Francis Island. Colonies of Bettongs also occur on the Venus Bay peninsula (P.Hone, SARDI, pers.comm.). The park is on the Register of the National Estate. Venus Bay is considered an area of particular natural beauty with a spectacular view of cliffs from Needle Eye Lookout. − The foreshore areas from east of Venus Bay to Port Kenny are considered to have some significance as bird habitat due to the presence of freshwater soaks. Common bird species in the area include: Chestnut Teal, Fairy Tern (rated `vulnerable', both for the State and region), Greenshank, Pied Oystercatcher, Red Neck Stint, Sharp-tailed Sandpiper and Sooty Oystercatcher. The small islands within the bay support nesting sites for Rock Parrots, Terns, Silver Gull, Pacific Gull, and also the Fairy Tern, while island `C' supports approximately 30 breeding pairs of Pelicans. The Caspian Tern also breeds on the islands (Copley 1996). The cliffs of the Venus Bay Conservation Park contain nests of the Osprey and White-breasted Sea-eagle. − Venus Bay is a popular recreational fishing locality (Starling 1986), supporting substantial and diverse areas of wetland that would provide habitat for estuarine and offshore fish stocks (Bucher & Saenger 1989). In particular, Venus Bay is considered an important nursery area for King George Whiting (Sillaginodes punctatus) (Jones 1980). This is because of the close association of juvenile fish with Zostera and Posidonia seagrass beds and tidal creeks. Tagging studies conducted by Jones (1980) in Venus, Baird and Murat Bays, indicate that fish tagged in these inshore bays remain in these bays for up to 2 years (ie. about 32-33cm length). From Venus Bay, the older fish may move out of the bay as far as Waldegrave Island (41km) and St Peter Island (153km) (Jones 1980). Anectdotal evidence suggests that the bay may also be a nursery area for Gummy Shark because of the high numbers of juveniles caught in the area (D.Mackie, PISA, pers.comm.). Venus Bay is also a significant nursery area for Australian Salmon (Cappo 1987). The size of the bay and the extent and − Venus Bay is also a significant nursery area for the Western King Prawn (Penaeus latisulcatus) (King 1977, Wallner 1985, Carrick 1993). Venus Bay represents the most significant nursery area for P.latisulcatus for the west coast prawn fishery. As such, it represents the principal nursery area for the Venus Bay trawl grounds, which contribute approximately 70% of the west coast prawn catch (Carrick 1993). The Venus Bay trawl grounds extend approximately 10 nautical miles offshore and cover an area of approximately 100 square nautical miles. A feature unique in South Australia, is the role of Venus Bay as a nursery area for both, juvenile and sub-adult P.latisulcatus (N.Carrick, SARDI, pers.comm.). Juvenile prawns occupy the intertidal regions of the bay, with subadults moving into the deeper parts of the bay. Juveniles of Western King Prawn are found in several shallow bays and tidal creeks in the Elliston-Venus Bay. The waters of these nursery areas are hypersaline, have high summer temperatures and invariably contain seagrass communities (mainly Posidonia australis); many, but not all, are associated with stands of mangroves (Avicennia marina) (King 1979). The substrate in these nursery areas varies from silty to clean sand with some shell grit. Substrates of soft mud or large quantities of shell grit appear not be preferred by juvenile Western King Prawn. Juvenile prawns utilise only areas of shallow, bare sand substrate (Wallner 1985). − Venus Bay consists of areas of samphire swamps and mangroves (0.40 km2) together with intertidal sand/mudflats (14.74 km2) (Bucher & Saenger 1989). Germain Island is a large mangrove and samphire swamp built by the tidal currents in Venus Bay. Avicennia marina on the south-eastern flank of Germein Island was recorded by Butler et al. (1975). Venus Bay has extensive areas of Zostera seagrass beds, particularly by the Venus Bay caravan park and also, in the north of the bay. The seagrass, Ruppia is also found in the far northern end of bay. Page 47 EYRE REGION - YANERBIE BIOUNIT Razorfish (Pinna sp.) used to occur near the Port Kenny jetty and in the western end of Venus Bay (D.Mackie, PISA, pers.comm.). 1.2 Physical − Geological Monuments None. 2 OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries in this region include Western King Prawn, Abalone and Southern Rock Lobster. There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand line. Some netting occurs inside parts of Venus Bay. Some of the Southern Bluefin Tuna boats use Thevenard as their major port of landing. Major single species fisheries in Venus Bay include Western King Prawn and Abalone (at the mouth of Venus Bay). There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand line. There are 5 licensed netters and 10 licensed hookers who work Venus Bay, plus a number of part-timer operators (T.Whibley, pers.comm.). Southern Rock Lobster This biounit represents a significant region for lobster fishing in South Australia. In 1995/96 and 1996/97 a total of 41 and 34 licensed operators fished in the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), catching approximately 168,235 and 161,534 kg of lobsters, respectively (or 3.23% and 3.16% of the total catch for Southern Rock Lobster in South Australian waters). Abalone The Blacklip Abalone and Greenlip Abalone is a significant fishery within the Yanerbie Biounit. In 1994/95 and 1995/96 a total of 30,222 and 33,657 kg of Greenlip was harvested within this region (ie. MapCode 4A-H, 5A-F, 6A-D, Point Westall to Venus Bay), and represented 13.3% and 14.9% of the total Greenlip Western Zone catch (or 8.02% and 8.99% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 76707 and 77,934 kg of Blacklip was harvested within this region, and represented 24.7% and 28.0% of the total Blacklip Western Zone catch (or 15.52% and 16.83% of the total catch for Blacklip in South Australian waters). Marine Scalefish Fisheries During 1995/96 and 1996/97, 42 and 44 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from Baird Bay and Venus Bay (ie. Fishing Zones 16 and 17), respectively. License holders expended approximately 2980 and 2,583 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zones 16 and 17) represented 78 928 kg in 1995/96 and 80 568 kg in 1996/97(or 0.76% and 0.79% of the total catch for the marine scalefish fishery in South Australian waters). Outside of Baird Bay and Venus Bay, during 1995/96 and 1996/97, 21 and 34 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), respectively. License holders expended approximately 570 and 899 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 15) represented 133 221 kg in 1995/96 and 283 665 kg in 1996/97(or 1.28% and 2.79% of the total catch for the marine scalefish fishery in South Australian waters). 2.2 Aquaculture Current aquaculture in this region is centred on Waterloo Bay (Elliston) and the southern end of Anxious Bay. The only oyster lease to be developed in Venus Bay and the few other attempts at growing oysters in the bay have all failed to demonstrate the economic viability of Pacific Oyster farming (GroveJones 1986, Hone 1993). The Elliston Aquaculture Management Plan (Ashman 1996) recommended the following aquaculture development in the region: Venus Bay Policy Area − Port Kenny Zone (waters of eastern side of bay, from Port Kenny to Germein Island to Venus Bay township) – zoned for aquaculture development of native species. Licenses will be considered for a maximum of 30ha of aquaculture development within this zone, excluding Pacific Oyster culture and species which require supplementary feeding. Page 48 EYRE REGION - YANERBIE BIOUNIT − Venus Bay Zone (remaining waters of Venus Bay) – zoned to protect and maintain existing values and uses. Licenses will not considered for aquaculture development within this zone. − Elliston Policy Area Elliston Zone (all waters of the Elliston Policy Area, from mouth of Venus to south of Sheringa Beach, excluding Venus Bay, but including Cap Island, Waldegrave Islands and The Watchers) – zoned to provide for aquaculture development. Licenses will be considered for a maximum of 60ha of aquaculture development within this zone, but not within Waterloo Bay and 1km of Waldegrave Islands, Cap Island, Lake Newland, Talia Caves and Venus Bay Conservation Parks. 2.3 Recreation and Tourism Agriculture/Industry − Recreational boat, jetty, rocks and beach fishing include King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Sweep, Garfish and Greenback Flounder as major species. − − SCUBA diving: Smooth Pool (south of Streaky Bay) is a recognised dive spot and listed in `Dive South Australia: The Best Dive Sites in South Australia (Diving Industry Association of South Australia). The dive is a ideal shallow, sheltered dive suitable for novice divers. 2.4 Scientific Research and Education − Significant scientific research and monitoring studies has been conducted by SARDI into the recruitment of Western King Prawn (Penaeus latisulcatus) in Venus Bay (Carrick 1993). 2.5 Adjacent Land Use National and Conservation Parks − Sceale Bay Conservation Reserve (485 ha). − Point Labatt Conservation Park (39 ha): adjoins the Point Labatt Aquatic Reserve (no access is permitted within 1 nautical mile) (DELM 1993). − Baird Bay Islands Conservation Park (24 ha), including Jones Island and an unnamed island at the head of the bay. Venus Bay. Port Kenny. 2.6 Significant Cultural and Historical Values Aboriginal − Tourism − Sealed and unsealed roads provide access to the shore. Jetties are located at Port Kenny and Venus Bay. Urban Centres Fishing − Venus Bay Conservation Park (1423 ha): consists of Venus Bay Peninsula (Cape Weyland), Germein Island and five other small islands in Venus Bay (Garden, Tank, A, B, C). − 3 The Venus Bay region has significant Aboriginal value. Nicholson (1991), in a survey of cultural sites in the area, identified seven occupation sites in Venus Bay. Nicholson (1991) descibed the area as an occupation site complex, consisting of seven open coastal campsites, one midden and an artefact or stone scatter. waterhole European Not known. CURRENT CONSERVATION STATUS OF THE YANERBIE BIOUNIT − Marine Reserves None − Marine Parks None − Netting Closures Baird Bay (all waters of Baird Bay). − Venus Bay (all waters of the eastern section of Venus Bay situated east of a straight line extending southerly across Venus Bay from the most westerly corner of section 72 hundred of Wright to the Trigonometrical Station on Point Weyland). Page 49 EYRE REGION - YANERBIE BIOUNIT 4 AREAS OF HIGH CONSERVATION IN THE YANERBIE BIOUNIT Sceale Bay-Smooth Pool − Prime IUCN Conservation Values: biodiversity, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (diversity of habitats, reefs, sand habitats), economic (major Blacklip Abalone fishing grounds), social (diving at Smooth Pool, scenic amenities), scientific (scientific monitoring), national/international, practicality (compatibility-adjacent to Sceale Bay Conservation Reserve). Caspian Tern, Osprey, White-breasted Sea Eagle, Silver Gull, Pacific Gull, Brush-tailed Bettongs, ecological integrity), economic (Western King Prawn, marine scalefish fisheries, tourism), social (aboriginal occupation site complex, scenic amenities, recreation), scientific (scientific monitoringWestern King Prawn), national (Register of the National Estate-Venus Bay Conservation Park, recognised estuary and wetland of importance), practicality (insulation, accessibility, compatibility-adjacent to Venus Bay Conservation Park and Conservation Reserve). Point Labatt-Baird Bay (and islands) − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to humaninduced change,), biogeographic (representative habitats), ecological (diversity of marine habitats, mangroves, seagrasses, wetland habitats, significant breeding colony of Australian Sea Lions at Point Labatt and Jones Island, nursery function, marine and wetland habitats, breeding population of Australian Pelicans-Jones Island, threatened waterbirds-Grey Plovers, White-bellied Sea Eagle, Osprey, Fairy Tern, ecological integrity), economic ((major Blacklip Abalone fishing grounds, Western King Prawn, scalefish fisheries, tourism), social (recreation, tourism, scenic amenities), scientific (scientific monitoring), national (international importance for shorebirdsBaird Bay, Wetland of National ImportancePoint Labatt, Baird Bay, Jones Island, Register of the National Estate-Point Labatt, Jones Island), practicality (accessibility, insulation, compatibility-adjacent to Baird Bay Islands Conservation Park). Venus Bay Conservation Park − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, aesthetics, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (diversity of marine habitats, mangroves, seagrasses, wetland habitats, key nursery function-Western King Prawn, scalefish, marine and wetland habitats, breeding population of Australian PelicansIsland C, seabirds-Rock Parrots, Fairy Tern, Page 50 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS VI MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE NEWLAND BIOUNIT This small biounit extends from Talia Caves to Cape Finniss on the Eyre Peninsula and covers an area of 45,238 ha and a coastal distance of 38 km. It faces southwesterly into the Great Australian Bight. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This biounit experiences wave energies ranging from low near Cape Finniss and in Waterloo Bay, to high around the offshore islands, cliffs and some sections of the mainland coast. Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperture of 14oC. The inshore coastal regions are very productive and are influenced by seasonal, nutrient-rich, coldwater upwellings (Wenju et al. 1990), which can result in an offshore sea surface temperature gradient of 18oC (in the Pearson Isles) to 11oC (off Waldegrave Islands) during the summer months. 2 GEOLOGY AND GEOMORPHOLOGY10 COASTAL This biounit is distinct because it is a continuous Holocene barrier bounded at either end by the extensive dune calcarenite cliffs of the Yanerbie Biounit and the Sheringa Biounit. Between Cape Finniss and Walkers Rocks, the 8km of shoreline is low-energy, with reflective beaches backed by up to 1km of Holocene dune transgression. The main barrier from Walkers Rock to Talia Monument is 26 km long and largely overlies Pleistocene deposits. Long Pleiocene reefs run parallel to the shore, approximately 1 km offshore. The whole barrier is backed by saline 20 km long Lake Newland which occupies the back barrier depression. The lake has been partially transgressed by the dunes throughout its length. In the southern half, past and present dune transgression has nearly filled the lake, reaching the eastern shore in places. The entire biounit is very dynamic and unstable (subject to both beach and dune instability). 10 There are two groups of offshore islands in the biounit: the Waldegrave Islands and The Watchers. Waldegrave Island is the largest of this group and consists of a crystalline basement (covered by calcareous aeolianite of varying thickness), which outcrops at the base of the island. Small sandy bays occur on the island, the largest on the northern side. A smaller island occurs to the west of Waldegrave Island and is similar, except there are no small beaches or inlets. The Watchers are two isolated outcrops of crystalline rocks. 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include sandy beaches, limestone rocky shores, and offshore islands. − Of the total inshore subtidal habitats mapped in the biounit (7,549ha), sandy bottoms comprise 4,318ha (57.2%), and limestone reefs comprise 3,231 (42.8%). No seagrass meadows have been mapped in the region. Major Benthic Communities • Macroalgal − At Anxious Bay, subtidal offshore rocky reef macroalgal communities (at 15m) dominated by the fucoids, Cystophora monoliformis, C.platylobium, and Ecklonia radiata and the red algae, Osmundaria, Phacelocarpus and Plocamium costatum. In the shallow, sheltered areas of Waldegrave Island (ie. 510m), the subtidal rocky shores are dominated by the fucoids, Cystophora monoliformis, C.pectinata, and C.monolifera and the red algae, Osmundaria, and species of Caulerpa (C.flexilis and C.cactoides). In Waterloo Bay, rocky areas are dominated by species of Cystophora, Ecklonia radiata and Scaberia agardhii (Shepherd & Womersley 1981). From Eyre Coast Protection District Study Report. Page 51 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS • Seagrass − At Waldegrave Island, deeper water seagrass communities dominated by Posidonia and Halophila occur. Within Waterloo Bay, seagrass communities occur dominated by Heterozostera tasmanica, Amphibolus antarctica and species of Posidonia (P.sinuosa, P.angustifolia, P.australis and P.ostenfeldii) (Shepherd & Womersley 1981). Fish species in the coastal lake include the Small-mouthed Hardyhead, Atherinosoma microstoma. Lake Newland Conservation Park: in a state-wide survey of wetlands conducted by Lloyd and Balla (1986), Lake Newland was considered to be an area of outstanding environmental value. Other Areas of Conservation Significance − Coastal and Offshore Islands (or Reefs) − Waldegrave Islands. − The Watchers. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND 1.1 Biological Peak catches occur during the winter months, primarily due to calmer weather enabling more fishing nights. Adults prawns spawn on the trawl grounds during the summer months, with a concentration of ripe females located inshore. Prawns move out in a southerly direction in Anxious Bay (from the entrance to Venus Bay) along the 30m contour, dispersing into the deeper waters of the Venus Bay trawl grounds (Wallner 1985). Coastal and Marine Wetlands of National Importance − Lake Newland has been identified as a wetland of national importance (see ANCA 1996). Lake Newland is a relatively permanent salt lake with freshwater springs, which is fed by seasonally by freshwater surface and groundwater sources, marine seepages and by occasional direct marine incursion. Lake Newland has been identified as an area of international importance for shorebirds by Watkins (1993). Lake Newland is one of the few permanent saltlakes located near the coast on Eyre Peninsula. The lake is the largest and supports a variety of wetland wildlife and serves as a drought refuge for numerous waterbirds and is a significant Hooded Plover, Thinornis rubricollis summer feeding habitat. Lake Newland also holds significant populations of several threatened species, including the Hooded Plover (Nv, Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Fairy Tern, Sterna nereis (Sv), Eastern Reef Egret, Egretta sacra (Sr), and the Peregrine Falcon (Fuhlbohm 1991). Cape Barren Geese (350 recorded) arrive in late spring, summer and autumn from nearby Waldegrave Island to feed. At least 34 species of waterbird have been recorded, 5 listed under international treaties. It can be assumed that the adjoining coastline is equally important. Anxious Bay produces approximately 80% of the west coast prawn catch for South Australia (Wallner 1985). The trawl grounds extend approximately 10 nautical miles offshore from Venus Bay and cover an area of approximately 100 square nautical miles (Carrick 1993). Larval P.latisulcatus migrate from the offshore spawning areas in Anxious Bay to the primary nursery area at Venus Bay (Wallner 1985). Baird Bay is of lesser importance as a nursery habitat because of the very high summer salinities (in excess of 60 ppt), with prawns restricted to the southern half of the bay (Wallner 1985). − Waldegrave Islands Conservation Park: these islands have a spectacular coastline of cliffs and sandy beaches, and also represent the second most important breeding area for Cape Barren Geese in South Australia. The birds that breed on Waldegrave Island stay in the Elliston area for the summer, feeding in swamps around the margins of Lake Newland and on grain in wheat paddocks. They roost on the beach or fly back to the island for the night. It is important for the overall conservation of this species in South Australia that this apparently separate population is disturbed as little as possible (Robinson & Heard 1985). Goose Island is an important Cape Barren Goose breeding area (T.Fulbohm, NPWS, pers.comm.). Breeding colonies of the Little Penguin are common on Little Waldegrave Island, while 300 pairs have been recorded on Waldegrave Island (Copley 1996). Page 52 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS − A small colony of Australian Sea Lions (38) have been recorded on West Waldegrave Island and are possibly breeding here. (Gales 1990). The islands are on the Register of the National Estate. 1.2 Physical Geological Monuments − Talia Caves is of State significance: the landforms developed in this area, particularly the caves and the mobile dune field, are spectacular. The region is an unspoilt wilderness. 2 OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries in this region include Greenlip and Blacklip Abalone and Southern Rock Lobster. There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand-line. Abalone The Western Zone for commercial abalone fishery is all those waters west of the latitude 136o30' east and includes all the waters of the management plan. There are 23 license holders in this zone. The Blacklip Abalone and Greenlip Abalone is a significant fishery within the Newland Biounit. In 1994/95 and 1995/96 a total of 15,327 and 1,9119 kg of Greenlip was harvested within this region (ie. MapCode 6E, 7A-B, 8A-E, 8Q, Anxious Bay, Waldegrave Island, The Watchers), and represented 6.7% and 8.5% of the total Greenlip Western Zone catch (or 4.07% and 5.11% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 20,556 and 17,217 kg of Blacklip was harvested within this region, and represented 6.6% and 6.2% of the total Blacklip Western Zone catch (or 4.16% and 3.72% of the total catch for Blacklip in South Australian waters). The `Hot Spot' near Ward Island and Waterloo Bay are very productive sites for commercial abalone harvesting. Elsewhere, abalone reefs are scattered throughout Anxious Bay, the offshore islands, the Elliston Cliffs (where abalone are found in the top 2 metres down to 20-25 metres, where it ends in sandy bottom), and the mouth of Venus Bay (S.Shepherd, SARDI, pers.comm.). There are 4 abalone divers for 4 licenses in the Elliston region. In addition, a further 19 divers work the waters off Elliston, occasionally diving in Waterloo Bay, but most commonly working off Anxious Bay and out to the offshore islands (T.Whibey, pers.comm). Blacklip Abalone are taken on calm seas from the shallower waters, while Greenlip Abalone are taken from the deeper water when there is a swell. Western King Prawn This biounit is located within the waters of the West Coast prawn fishery, which comprises 3 license holders (ie. Boats). All vessels fish within the waters of this biounit (ie. Fishing Zones 15), the Nuyts Biounit (ie. Fishing Zone 8) and the Douglas Biounit (ie. Fishing Zone 27). In 1995/96 and 1996/97 a total of 200,764 and 166,414 kg was caught for this fishery, with a total effort of 3,144 and 2,778 hours, respectively (or 8.84% and 8.22% of the total catch for Western King Prawn in South Australian waters). Marine Scalefish Outside of Baird Bay and Venus Bay, during 1995/96 and 1996/97, 21 and 34 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), respectively. License holders expended approximately 570 and 899 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 15) represented 133,221 kg in 1995/96 and 283,665 kg in 1996/97(or 1.28% and 2.79% of the total catch for the marine scalefish fishery in South Australian waters). There are 5 marine scalefish licenses in Elliston, comprising 3 A class and 2 B class fishing licenses. Operators fish mainly in the vicinity of Anixous Bay, Waldegrave Island and Flinders Island (T.Whibley, pers.comm.). Southern Rock Lobster This biounit represents a significant region for lobster fishing in South Australia. In 1995/96 and 1996/97 a total of 41 and 34 licensed operators fished in the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), catching approximately 168,235 and 161,534 kg of lobsters, respectively (or 3.23% and 3.16% of the total catch for Southern Rock Lobster in South Australian waters). Page 53 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS One lobster boat works from Elliston as far north as Talia Caves, south to Tungketta Reef and out to Flinders Island. In addition, another two or so boats come from Port Lincoln to work the grounds (T.Whibley, pers.comm.). 2.4 Scientific Research and Education − Beach litter surveys. Anxious Bay is the site of the longest and only regular survey of marine (or ship-based) litter in Australia (see Wace 1995). The survey is a communitybased survey of beach litter, which is coordinated by the SA Research and Development Institute and undertaken with the assistance of staff and students from the Streaky Bay Area School, Elliston Primary School and the Cavan Centre for Juvenile Detention. − Researchers from the SA NPWS regularly conduct ornithological surveys of the region, particularly for Cape Barren Geese. − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks; and regular research and monitoring of South Rock Lobster field stocks. Other There is one licensed shell collector in the Anxious Bay region (T.Whibley, pers.comm.). 2.2 Mariculture Current aquaculture in this region is centred on Waterloo Bay (Elliston) and the southern end of Anxious Bay. The Elliston Aquaculture Management Plan (Ashman 1996) recommended the following aquaculture development in the region: Elliston Policy Area − Elliston Zone (all waters of the Elliston Policy Area, from mouth of Venus to south of Sheringa Beach, excluding Venus Bay, but including Cap Island, Waldegrave Islands and The Watchers) – zoned to provide for aquaculture development. Licenses will be considered for a maximum of 60ha of aquaculture development within this zone, but not within Waterloo Bay and 1km of Waldegrave Islands, Cap Island, Lake Newland, Talia Caves and Venus Bay Conservation Parks. 2.3 Recreation and Tourism − Talia Caves and beach have great aesthetic appeal because of their natural, pristine state. − Walker's Rock is a focal point for camping and picnicking activities in the area. − SCUBA diving: Waldegrave Island and Little Waldegrave (north of Elliston) is a recognised dive spot and listed in `Dive South Australia: The Best Dive Sites in South Australia (Diving Industry Association of South Australia’). The reefs which drop down to 24m are honeycombed with holes, ledges, caves and walls and are the home of sponges, ascidians, gorgonians, crinoids and soft corals. Many types of fish are recorded here including Blue Devils, Red-banded Sea Perch and Scaly Fins. Sea Lions inhabit the north western side of Little Waldegrave. 2.5 Adjacent Land Use National and Conservation Parks − Lake Newland Conservation Park (8,448 ha). − Waldegrave Islands Conservation Park (434 ha). Agriculture/Industry − There is no significant development along this biounit, and very limited access. Road access to a boat ramp one kilometre north of Cape Finniss and to Walkers Rocks. Along the remaining section of coast, several 4WD tracks exist, but access along these is difficult. Urban Centres − None. Page 54 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS 2.6 Significant Cultural and Historical Features − − 3 Aboriginal Newland Barrier, south of Talia Caves: an occupation site consisting of an artefact manufacturing site (Nicholson 1991). European None. CURRENT CONSERVATION STATUS OF THE NEWLAND BIOUNIT − Marine Reserves None − Marine Parks None − Netting Closures None 4 The Watchers Conservation Park − Waldegrave Islands Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, research (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (breeding colonies of Cape Barren Goose, Little Penguin, nesting site for Ospreys, breeding site for Australian Sea Lion), economic (Blacklip Abalone, Greenlip Abalone, Southern Rock Lobster, marine scalefish fisheries, tourism), social (scenic amenities, SCUBA diving, recreation), scientific (scientific monitoringCape Barren Goose), national (Register of the National Estate-Waldegrave Islands Conservation Park), practicality (insulation, compatibility-adjacent to Waldegrave Islands Conservation Park). AREAS OF HIGH CONSERVATION VALUE IN THE NEWLAND BIOUNIT Talia Caves - Lake Newland Conservation Park − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, cultural, aesthetics, research (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (Talia Caves-unique geology, representative marine habitats), ecological (reef, sand habitats, wetland habitats, threatened birds-Hooded Plover, Cape Barren Goose, Fairy Tern, Eastern Reef Egret, Peregrine Falcon, ecological integrity), economic (Blacklip Abalone, Greenlip Abalone, Southern Rock Lobster, marine scalefish fisheries, tourism), social (aboriginal occupation site, recreation, scenic amenities), scientific (scientific monitoring-beach litter surveys), international/national (international importance for shorebirds and Wetland of National Importance-Lake Newland Conservation Park), practicality (insulation, accessibility, compatibility-adjacent to Lake Newland Conservation Park). Page 55 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS VII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE SHERINGA AND FLINDERS BIOUNITS This coastal region comprises 2 biounits: the inshore coastal Sheringa Biounit, and the offshore Flinders Biounit, which is defined by the 50 metre bathymetric contour. The Sheringa Biounit extends from Cape Finniss to Drummond Point on the Eyre Peninsula and covers an area of 51,156 ha and a coastal distance of 81 km. The Flinders Biounit encompasses the Investigator Group and covers an area of 125,957 ha. The region faces southwesterly into the Great Australian Bight. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This biounit experiences wave energies ranging from low in Waterloo Bay, to very high around the offshore islands and some sections of the mainland coast. Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperture of 14oC. The inshore coastal regions are under the influence of seasonal coldwater, nutrient-rich coastal upwellings which occur close to the coast, which can result in an offshore sea surface temperature gradient of 18oC (eg. in the Pearson Isles) to 11oC (eg. off Waldegrave Islands) during the summer months. The major focus of the coastal upwelling appears to extend from the Coffin Bay Peninsula to Cape Borda (Kangaroo Island) (Wenju et al. 1990) and in part, may be responsible for the very high levels of productivity and marine benthic biodiversity in the region. Recent studies indicate that is a relationship between the upwellings and the pilchard abundance in these areas (Ward & McLeay 1998). 2 GEOLOGY AND GEOMORPHOLOGY11 This Flinders Biounit contains a number of offshore islands. The most well known and most studied, is the Investigator Group of islands. These islands are true `inselbergs' (island mountains), and include: − Flinders Island is a low mass of granite, with boulders on its flanks, but capped by limestone. Small sandy bays and inlets occur between basement headlands and on the northern coast two lakes are separated from the sea by a narrow strip of coastal dunes. − Pearsons Islands are high granite islands rising abruptly 240m from the eastern section of the Great Australian Bight. They take the form of domes which are rounded and boulder strewn on the upper slopes, with massive curvilinear sheets on the lower levels. Flared slopes and tafoni are well developed. The western exposed shores are strongly cliffed. − Topgallant Islands consists of one main island and a number of smaller islands. The smaller islands appear to be entirely basement. The larger island has a thick cover of calcareous aeolianite with extremely steep sides. Beach sand has been deposited in one small inlet. − Ward Island and Cap Island (together with the nearby reefs and inlets), are crystalline basement, with thin covers of calcareous aeolianite. COASTAL The Sheringa Biounit consists of an almost straight section of Pleistocene dune calcarenite cliffs averaging 40-50 m high at the shoreline and climbing to over 100 m along much of the coast. The cliffs are breached only by two relatively small bays (Sheringa and Waterloo Bay). At Point Drummond the calcarenite mantles have been wave eroded to form shore platforms (Twidale et al. 1977). The shoreline consists of reefs and shore platforms, as well as beach-surf zone and surf zone. 11 Holocene barrier dune transgression occurs at Sheringa and a single foredune barrier within Waterloo Bay occurs where the Pleistocene dune calcarenite has been completely breached. However, wave refraction into Waterloo Bay and attenuation over shallow reefs which block much of the entrance, has produced low waves at the shoreline. Consequently, unlike the higher energy Sheringa, the low wave conditions in the bay have resulted in a low energy reflective beach backed by a single moderately stable foredune barrier. From the Eyre Coast Protection Distric Study Report. Page 56 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS 3 BIOLOGY Major Inshore Habitats − − Major intertidal habitats in the region include mostly rocky limestone shores, offshore islands, and some sandy beaches. Of the total inshore subtidal habitats mapped in the Sheringa Biounit (4,894 ha), limestone reefs comprise 4,605 ha (94.1%), sandy bottoms comprise 224 ha (4.6%), and seagrass meadows comprise 65 ha (1.3%). Of the total inshore subtidal habitats mapped in the Flinders Biounit (4,194 ha), limestone reefs comprise 4,194 ha (100%) of the habitats mapped. No significant areas of seagrass were mapped. MARINE CONSERVATION VALUES 1 Macroalgal − At Ward Island, subtidal offshore rocky reef macroalgal communities dominated by species of Cystophora (C. monoliformis, C.monolifera, C.siliquosa, and C.pectinata), and Ecklonia radiata and species of Caulerpa (C.flexilis, C.longifolia), articulated corallines and the red algae, Plocamium costatum. At Pearson Island, on exposed subtidal rocky shores, Cystophora is replaced by the Acrocarpia paniculata, and Homeostrichus. − Macroalgal communities at Topgallant Island, Hotspot, Ward Island are similar to Pearson Island (Branden et al. 1986). • Seagrass − At Pearson Island and Ward Island, deepwater (20-30m) communities of seagrasses occur, dominated by Heterozostera tasmanica, Halophila, Amphibolis and Posidonia australis. Coastal and Offshore Islands (or Reefs) Coastal and Marine Wetlands of National Importance − Lake Hamilton has been identified as a wetland of national importance (see ANCA 1996). Lake Hamilton is a coastal gypsum lake separated from the ocean by steep cliffs. The lake and environs contains an excellent range of habitat types which could be important for bird breeding. There is no recognised threatened fauna or flora within the region. However, threatened waterbirds in the area include possibly the Hooded Plover, Thinornis rubricollis (Nv, Sv) on beaches, and Osprey, Pandion haliaetus (Sv). Lake Hamilton was considered by Lloyd and Balla (1986) to be an area of outstanding environmental value, which recommended that the area be given status as a wetland reserve. − Sheringa Lagoon was considered by Lloyd and Balla (1986) to be an area of outstanding environmental value, which recommended that the area be given status as a wetland reserve. Inshore Islands of Conservation Value − Cap Island Conservation Park. The fauna of this island is typically oceanic. It has a small breeding colony of the White-faced Storm Petrel (325 pairs) (Copley 1996) and the westernmost record of the White-fronted Tern (Sterna striata) in South Australia. The island is on the Register of the National Estate. Offshore Islands of Conservation Value − The Investigator Group of Islands (including Flinders Island, Pearsons Islands, Topgallant Islands and Ward Islands). Pearson Island has been the site of a number of major scientific research investigations. The subtidal flora is characterised by a high species diversity and an abundance of algae, while the island itself is in a relatively pristine state, because of its unsuitability for farming or grazing sheep (due to the lack of permanent fresh water). There is a colony of Pearson Island Rock Wallabies (Petrogale pearsoni) on the island. − A total of 41 species of birds have been recorded on Pearson Island, of which half are The Investigator Group of Islands comprising Flinders Island, Pearsons Islands (Pearson, North Veteran, South Veteran, Dorothee), Topgallant Islands and Ward Islands. − − AND 1.1 Biological Major Benthic Communities • SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES Cap Island (offshore from Sheringa). Tungketta Reef. Page 57 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS terrestrial species. This is unusually high for an island of this nature. − − − The islands of the Investigator Group contain significant breeding colonies of Australian Sea Lions (Neophoca cinerea) and New Zealand Fur Seals (Arctocephalus forsteri). Breeding colonies of sea lions have been recorded on Ward Island (43 pups, estimated population 206), and Pearson island (35 pups, estimated population 168). While possible breeding occurs on Dorothee Island (Gales 1990). Haul out sites occur on SE Ward, North Veteran and Top Gallant (Gales et al. 1994). Breeding colonies of fur seals have been recorded on Pearson and Ward (64 pups, estimated population 314), while haul outs occur on Pearson, North Veteran and Dorothee Islands (Shaughnessy et al. 1994). The Investigator Group contains significant colonies of protected seabird species, such as the Little Penguin, Short-tailed Shearwater and the White-faced Storm Petrel (Eckert 1970). Two colonies of the `vulnerable' Fairy Tern occur on Pearson Island. Colonies of the Little Penguin occur on Dorothee Island and Pearson Island (Copley 1996). Colonies of the Short-tailed Shearwater occur on Dorothee Island (1,896 pairs), North Veteran (474 pairs), Topgallant Island (474 pairs), and Ward Island (1,896 pairs) (Copley 1996). Colonies of the White-faced Storm Petrel occur on Dorothee Island (5,200 pairs), Topgallant Island (3,900 pairs) and Ward Island (326 pairs) (Copley 1996). Breeding colonies of the Pacific Gull occur on Pearson and Dorothee Island. Caspian Terns breed on Pearson Island, while the Red-tailed Tropicbird has been recorded on Pearson and Flinders Island. The Investigator Group of Islands is on the Register of the National Estate. An expedition to Pearson Island in 1969 showed the waters surrounding the island contained highly diverse and abundant flora, extending beyond 40 m deep (Shepherd & Womersley 1971). This deep algal growth has been attributed to the clear oceanic water allowing high light penetration and adequate water movement. There were differences found in species assemblages between rough and sheltered sites around the island. A richer flora of Chlorophyta and Rhododphyta was developed at the rougher sites whereas the Phaeophyta were more abundant at the sheltered sites (Shepherd & Womersley 1971). Few subtidal grazing animals were observed, although the giant Turban Dinassovica jourdani was observed occasionally at depths below about 20m in roughwater localities where it browses on red algae. − A comparison between the Pearson Island and West Island (off the Fleurieu Peninsula) flora showed several important differences. Pearson Island flora is richer in Chlorophyta and Phaeophyta, although similar in the number of Rhodophyta (however, further collecting at Pearson Island is likely to increase the total number of species, particularly the Rhododphyta). There was also greater species diversity at Pearson Island, especially in the Rhodophyta (Shepherd & Womersley 1971). − Topgallant Islands have high aesthetic marine topographic features. The benthic communities have one of the highest levels of biodiversity for ascidians, and marine algae in the world (S.Shepherd, SARDI, pers.comm.). − Fish fauna of the Investigator Group of islands is diverse (Kuiter 1983, Branden et al. 1986). A total of 20 species was recorded at Topgallant Island, 13 species at Hotspot, 15 species at Ward Island, and 16 species at Pearson Island. Of particular significance is the abundance of large fishes, such as the Blue Groper (Achoerodus gouldii) that were recorded in 15 out of 18 transects. These reefs are rarely visited by spear-fishermen and consequently, reveal fish abundances in virtually unexploited conditions (Branden et al. 1986). Other Areas of Recognised Conservation Significance − Waterloo Bay is a highly favourable habitat for abalone production (S.Shepherd, SARDI, pers.comm.). − Waterloo Bay has a very high level of habitat diversity. Within Waterloo Bay, a total of 7 benthic macroalgal communities have been identified on rocky substratum (Shepherd & Womersley 1981). These included a roughwater algal turf community (comprising predominantly stunted brown fucoid algae), a red algal shade community, two Ecklonia radiata communities (with Cystophora platylobium and Acrocarpia paniculata as codominants), a Cystophora-complex community (dominated by 9 species of Cystophora), a Cystophora-SargassumOsmundaria community, and a community dominated by Scaberia agardhii. On sandy substratum, 5 seagrass communities have been identified, dominated by Heterozostera tasmanica, Amphibolus antarctica, Posidonia australis, P.sinuosa with P.angustifolia, and P.ostenfeldii (Shepherd & Womersley 1981). Page 58 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS 1.2 Physical Geological Monuments − 2 Drummond Point is "geological monument" of State significance. Features of geological and geomorphological interest include: welldeveloped shore platforms; Archaean Kiana Granite (amongst the oldest rocks in South Australia); and a major mylonite zone. OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries in this region include Greenlip and Blacklip Abalone and Southern Rock Lobster. There is also a considerable marine scalefish fishery targeting mainly King George Whiting by hand line. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Elliston: 1 northern zone Rock Lobster license, 1 restricted marine scalefish license, 3 unrestricted marine scalefish licenses. In 1994/95 and 1995/96 a total of 64263 and 49302 kg of Blacklip was harvested within this region, and represented 20.7% and 17.7% of the total Blacklip Western Zone catch (or 13.00% and 10.65% of the total catch for Blacklip in South Australian waters). In contrast, the offshore Flinders Biounit is one of the major abalone fishing grounds in South Australia. In 1994/95 and 1995/96 a total of 52236 and 62819 kg of Greenlip was harvested within the Flinders Biounit (ie. MapCode 9A-H, 8P, 10C, Flinders Island, The Hotspot, Ward Islands, Pearson Islands), and represented 23.0% and 27.8% of the total Greenlip Western Zone catch (or 13.87% and 16.78% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 30,681 and 40,947 kg of Blacklip was harvested within this region, and represented 9.9% and 14.7% of the total Blacklip Western Zone catch (or 6.21% and 8.84% of the total catch for Blacklip in South Australian waters). The `Hot Spot' near Ward Island and Waterloo Bay are very productive sites for commercial abalone harvesting. Elsewhere, abalone reefs are scattered throughout Anxious Bay, the offshore islands, the Elliston Cliffs (where abalone are found in the top 2 metres down to 20-25 metres, where it ends in sandy bottom), and the mouth of Venus Bay (S.Shepherd, SARDI, pers.comm.). Abalone The Western Zone for commercial abalone fishery is all those waters west of the latitude 136o30' east and includes all the waters of the management plan. There are 23 license holders in this zone. Within this region, most of the Greenlip Abalone is presently harvested within the offshore Flinders Biounit, while the Blacklip Abalone fishery is significant in both the offshore and also, the inshore waters of the Sheringa Biounit. In 1994/95 and 1995/96 a total of 3309 and 2589 kg of Greenlip was harvested within the Sheringa Biounit (ie. MapCode 8F-H, 8J-N, 10A-B, 11A-C, Waterloo Bay, Elliston Cliffs to Kiana Cliffs region), and represented 1.5% and 1.1% of the total Greenlip Western Zone catch (or 0.88% and 0.69% of the total catch for Greenlip in South Australian waters). There are 4 abalone divers for 4 licenses in the Elliston region. In addition, a further 19 divers work the waters off Elliston, occasionally diving in Waterloo Bay, but most commonly working off Anxious Bay and out to the offshore islands (T.Whibey, pers.comm). Blacklip Abalone are taken on calm seas from the shallower waters, while Greenlip Abalone are taken from the deeper water when there is a swell. Marine Scalefish During 1995/96 and 1996/97, 21 and 34 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), respectively. License holders expended approximately 570 and 899 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 15) represented 133,221 kg in 1995/96 and 283,665 kg in 1996/97(or 1.28% and 2.79% of the total catch for the marine scalefish fishery in South Australian waters). Page 59 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS Licenses will be considered for a maximum of 60ha of aquaculture development within this zone, but not within Waterloo Bay and 1km of Waldegrave Islands, Cap Island, Lake Newland, Talia Caves and Venus Bay Conservation Parks. There are 5 marine scalefish licenses in Elliston, comprising 3 A class and 2 B class fishing licenses. Operators fish mainly in the vicinity of Anixous Bay, Waldegrave Island and Flinders Island (T.Whibley, pers.comm.). Southern Rock Lobster Drummond Point Policy Area This biounit represents a significant region for lobster fishing in South Australia. In 1995/96 and 1996/97 a total of 41 and 34 licensed operators fished in the Anxious Bay and inshore Investigator Group region (ie. Fishing Zone 15), catching approximately 168,235 and 161,534 kg of lobsters, respectively (or 3.23% and 3.16% of the total catch for Southern Rock Lobster in South Australian waters). During this same period, a total of 11 and 5 licensed operators fished in the offshore Investigator Group region (ie. Fishing Zone 14), catching approximately 6, 152 and 4,557 kg of lobsters, respectively (or 0.12% and 0.09% of the total catch for Southern Rock Lobster in South Australian waters). In the inshore region, south of Elliston, a total of 15 and 15 licensed operators fished in the Sheringa Biounit region (ie. Fishing Zone 18), catching approximately 15,342 and 10 878 kg of lobsters, respectively (or 0.30% and 0.21% of the total catch for Southern Rock Lobster in South Australian waters). One lobster boat works from Elliston as far north as Talia Caves, south to Tungketta Reef and out to Flinders Island. In addition, another two or so boats come from Port Lincoln to work the grounds (T.Whibley, pers.comm.). 2.2 Aquaculture − Flinders No marine-based aquaculture current exists in this region. The Elliston Aquaculture Management Plan (Ashman 1996) recommends limited aquaculture development in the region: Investigator Group Policy Area − Investigator Group Zone (coastal waters, within 3nm of the coast, surrounding Ward Islands, Pearson Isles, Veteran Isles, Dorothee Island, and Topgallant Island) – zoned to maintain and protect current uses and values. Licenses will not be considered for aquaculture development within this zone. − Flinders Island Zone – zoned to provide for aquaculture development. Licenses will be considered for a maximum of 40ha of aquaculture development within this zone. Sheringa Current aquaculture in this region is centred on Waterloo Bay (Elliston) and the southern end of Anxious Bay (Ashman 1996). No marine-based aquaculture current exists in this region. The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) and the Elliston Aquaculture Management Plan (Ashman 1996) recommends aquaculture development in the following areas: 2.3 Recreation and Tourism Fishing − Anxious Bay: boat, beach, and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Sweep, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Flinders Island: boat, beach, and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Sweep, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. Elliston Policy Area − Elliston Zone (all iwaters of the Elliston Policy Area, within 3nm of coast, from mouth of Venus to south of Sheringa Beach, excluding Venus Bay, but including Cap Island, Waldegrave Islands and The Watchers) – zoned to provide for aquaculture development. Drummond Point Zone (ie. inshore waters from Sheringa Beach south to Point Sir Isaac, east to Frenchman Bluff) – zoned to protect conservation values and existing fishing, recreational and tourist use. Licenses will not be considered for aquaculture development in this zone. Page 60 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS − Elliston Waterloo Bay: boat, jetty, beach, and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Sweep, Garfish, Tommy Rough, Trevally, Silver Drummer and Southern Calamari. − Locks Well: beach fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon and Tommy Rough. − Sheringa: beach and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon and Tommy Rough. 2.4 Scientific Research and Education − Islands in the Investigator Group have long been the site of a number of marine and terrestrial biological studies by both, fisheries scientists and researchers from the SA Museum and various research institutions (Shepherd 1969, Specht 1969, Shepherd & Womersley 1970, Twidale 1971, Branden et al. 1986). The most well studied of these islands is Pearson Island, where research dates back to a scientific expedition to the island in 1923. In 1969, a comprehensive marine biological survey of Pearson Island was conducted jointly by the Department of Fisheries and Fauna Consevation of South Australia and the Royal Society of South Australia (see Shepherd & Womersley 1970, Burn 1973, Seed 1973, Watson 1973). Because of its relatively undisturbed state, it is probably the most scientifically important of the State's offshore islands. − Researchers from the NPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies in this region. − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks; and regular research and monitoring of South Rock Lobster field stocks. Tourism − Elliston is a popular site on the shores of Waterloo Bay. Its rugged cliffs and spectacular coastline have great aesthetic appeal. The town itself is popular for its clear and unspoilt beaches and fishing. The sheltered bays offer swimming, sailing, diving or watersports. Elliston is a popular campsite for recreational diving clubs. − `Blackfellows' at Anxious Bay is a popular surfing spot and Sheringa Lagoon is a popular camping spot. − The Investigator Group of Islands are popular for charter boats (eg. Failie Charters) for fishing, SCUBA diving, Southern Rock Lobster, and shark spotting (especially at Pearson Island). − Recreational divers target Waterloo Bay, Talia Caves and Anxious Bay for Southern Rock Lobster, Abalone and occasionally, Scallops. − SCUBA diving: Pearson Island is a recognised dive spot and listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The island is recognised for its populations of seals and dolphins, fish (particularly Blue Devils, Leafy Seadragons, and giant Blue Groper) and also, giant sponges, gorgonians and soft corals. 2.5 Adjacent Land Use National and Conservation Parks − Investigator Group Conservation Park (117 ha). This park excludes the two largest islands in the Investigator Group, Flinders and Pearson Islands. Flinders Island is held as a pastoral lease while Pearson Island is a Lighthouse Reserve managed by the Commonwealth Government. − Cap Island Conservation Park (8 ha). Page 61 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS Agriculture/Industry − The remains of 3 shipwrecks are known to occur in the region and are protected under Commonwealth legislation: the schooner `Vulcan’ which was wrecked at Flinders Island in 1845, and the schooners `Freebridge’ and `Fanny Wright’, which were wrecked in Waterloo Bay in separate incidents in 1877. − The cutter `Fire Fly’ was wrecked in 1866, somewhere in Anxious Bay, near Elliston, but has not been located. In addition 2 other wrecks are of historical interest, but have not been declared at this stage (Ashman 1996): the ketch `Lady Flinders’ which was wrecked at Flinders Island in 1937 and the screw steamer `Kapara’ which was also wrecked at Flinders Island in 1942. 3 CURRENT CONSERVATION STATUS OF THE SHERINGA AND FLINDERS BIOUNITS Apart from the township of Elliston, there is little urban development along this biounit. Most adjacent coastal land in this biounit is used for agriculture. There is a pastoral lease on Flinders Island. − Urban Centres Elliston (population 209). 2.6 Significant Cultural and Historical Features Aboriginal − Blackfellows, near Cape Finniss: possible site of a major massacre of indigenous inhabitants (A. Nicholson, pers.comm.). − Hill Bay, Drummond Point (not dated): an occupation complex consisting of middens and artefact scatters. Has potential for National Estate listing (A. Nicholson, pers.comm.). 3.1 Sheringa Biounit European A number of coastal structures and sites in this region have recognised heritage value: − Marine Reserves None Sealing site at Flinders Island (registered on the State Heritage Register). − Marine Parks None − Elliston jetty and a cast iron navigation light (both on the State Heritage Register). − − Venus Bay and Port Kenny jetties (considered to have local heritage value). • − 3.2 Flinders Biounit Shipwrecks − A number of shipwrecks are located in this region. The waters of Venus Bay and up to the Anxious Bay closing line, are covered by the (South Australian) Historic Shipwrecks Act 1976. This allows for the protection of shipwrecks through the declaration of individual wrecks as historic. Waters outside the Anxious Bay closing line fall under the jurisdiction of the (Commonwealth) Historic Shipwrecks Act 1976. Wrecks within these waters that are in excess of 75 years old are automatically protected under this act. Other wrecks may be protected under this Act if of significant value. Netting Closure Waterloo Bay (all of the waters inside of Waterloo Bay, Elliston, situated north east of a line from Wellington Point to Salmon Point). − Marine Reserves None − Marine Parks None − Netting Closure None. Page 62 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS 4 AREAS OF HIGH CONSERVATION VALUE IN THE SHERINGA AND FLINDERS BIOUNITS Cap Island Conservation Park − 4.1 Sheringa Biounit Waterloo Bay − Prime IUCN Conservation Values: biodiversity, research, cultural, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to humaninduced change), biogeographic (representative marine habitats), ecological (ecological integrity, diversity of marine habitat types, reefs, seagrass meadows), economic (fisheries, tourism), social (historic shipwrecks`Freebridge’, `Fanny Wright’, scenic amenities), scientific (scientific research and monitoring-abalone), practicality (accessibility). Drummond Point Prime IUCN Conservation Values: cultural values, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (geological monumentDrummond Point), ecological (White-faced Storm Petrel, White-fronted Tern), economic (Southern Rock Lobster, significant area for Blacklip Abalone, tourism), social (aboriginal occupation complex at Hill Bay, recreation, scenic amenities), scientific (scientific monitoring), national (potential for listing on the Register of the National Estate), practicality (insulation). Lake Hamilton − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, aesthetics, research (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (wetland habitats, threatened waterbirds - Hooded Plover, Osprey, Cape Barren Goose, ecological integrity), economic (Southern Rock Lobster, fisheries, tourism), social (scenic amenities), scientific (scientific monitoring), national (Wetland of National Importance-Lake Newland), practicality (insulation, accessibility, compatibility-adjacent to Lake Hamilton wetland,). Sheringa Beach and Lagoon − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, research (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (wetland habitats, threatened birds particularly Hooded Plover, Cape Barren Goose, ecological integrity), economic (Southern Rock Lobster, significant area for Blacklip Abalone, tourism), social (recreation, scenic amenities), scientific (scientific monitoring-abalone), national (recognised wetland of importance), practicality (insulation, accessibility, compatibility-adjacent to Sheringa Lagoon wetland). Prime IUCN Conservation Values: biodiversity, research (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats), ecological (breeding colonies of White-faced Storm Petrel, White-fronted Tern), economic (Southern Rock Lobster, Blacklip Abalone, fisheries, tourism), social (scenic amenities, recreation), scientific (scientific monitoring), national (Register of the National Estate), practicality (insulation, compatibility-adjacent to Cap Island Conservation Park). 4.2 Flinders Biounit Investigator Group − Prime IUCN Conservation Values: biodiversity, aesthetic values, rare and endangered species/habitats, research (IUCN Category IB). IUCN Identification Criteria: naturalness (not subject to human-induced change), biogeographic (representative marine habitats, unique geology), ecological (benthic biodiversity, Pearson Island Rock Wallabies, Australian Sea Lions, breeding colonies and haul out sites for New Zealand Fur Seals-Ward, Veteran, Pearson, Dorothee Islands, breeding colonies and haul out sites for Australian Sea Lions-Ward, Pearson, Dorothee, Veteran, Topgallant, breeding/nesting colonies of seabirds - Little Penguin, Short-tailed Shearwater, White-faced Storm Petrel, Fairy Tern, Sooty Oystercatcher, Pacific Gull), economic (significant area for Greenlip Abalone, Blacklip Abalone, fisheries, tourism), social (wilderness values, scenic amenities, past historical studies, recreational use), scientific (past and present scientific research – Pearson Isles, Topgallant Islands), national (Register of Page 63 EYRE REGION – SHERINGA AND FLINDERS BIOUNITS the National Estate-Investigator Group Conservation Park), practicality (extension of Investigator Group Conservation Park, compatibility). Flinders Island − Prime IUCN Conservation Values: biodiversity, cultural values, rare and endangered species/habitats, research (IUCN Category II). IUCN Identification Criteria: naturalness (scenic amenities), biogeographic (representative marine habitats), ecological (nesting sites for Ospreys, White-bellied Sea Eagle, breeding sites for Little Penguins), economic (significant area for Blacklip Abalone, Greenlip Abalone, fisheries, tourism), social (historic shipwrecks - `Vulcan’, `Lady Flinders’, `Kapara’, recreation), scientific (scientific monitoring), national (Register of the National Estate), practicality (extension of Investigator Group Conservation Park, compatibility). Page 64 EYRE REGION – DOUGLAS BIOUNIT VIII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE DOUGLAS BIOUNIT This biounit extends from Drummond Point to Point Sir Isaacs on the south-eastern tip of Eyre Peninsula, and covers an area of 67,645 ha and a coastal distance of approximately 73 km. It is oriented in a generally southerly direction into the Southern Ocean. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This biounit has high energy coastline with low energy bays. From Cape Catastrophe to Point Sir Isaac (167 km) the south-west facing coast is exposed to high energy and is one of the highest wave energy shorelines in Australia, rivalling Canunda in the South-East (Short & Hesp 1984). Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperture of 14oC. The inshore coastal regions are under the influence of seasonal coldwater, nutrient-rich coastal upwellings which occur close to the coast, which can result in an offshore sea surface temperature gradient of 18oC to inshore temperatures of 11oC in inshore areas during the summer months (Wenju et al. 1990). There appears to be a relationship between the upwellings and the pilchard numbers in these areas (Ward & McLeay 1998). 2 GEOLOGY AND GEOMORPHOLOGY12 COASTAL From Point Sir Isaac to Point Drummond (133 km, including Port Douglas) there is 73 km of open coast shoreline with highly variable orientation and exposure, coupled with more than 60 km of highly crenulate bay shoreline in Port Douglas (Coffin Bay). The protection from the Southern Ocean swell afforded by the Coffin Bay Peninsula has produced a far lower energy coastline that the southern coast. Consequently, while Holocene sedimentation has been extensive, most is confined to intertidal and subtidal sandflats and bay floor deposits, with beachbarrier-dune deposits only beginning to appear along the northern section of coast, which is increasingly exposed to the ocean wave conditions. 12 Port Douglas (including Kellidie and Mount Dutton Bays) is the largest bay on the Eyre Peninsula, with an overall area of 120 km2 and 60 km of shoreline. Coffin Bay is a more protected bay with a low energy open coast. The present shoreline of Port Douglas, Mount Dutton and Kellidie Bays consists of three types: (i) stable dune calcarenite cliffs, usually only a few metres high and notched in the intertidal zone dominate the northern shoreline, and are common on southern promontories; (ii) low energy intertidal deposits consisting of shelly sandflats backed by supratidal samphire flats in very protected environments, such as upper Mount Dutton Bay, Kellidie Bay and Yangie Bay; (iii) low energy reflective beaches, usually backed by small foredunes and fronted by low gradient sandflats in the more exposed locations, particularly along the southern and western shores of Port Douglas and Point Longnose. A number of offshore islands occur in this biounit: − Rocky Island (North): entirely basement rock. − Mt Dutton Bay Islands (7 islands). 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include bays, sandy beaches and some rocky shores and islands. − Of the total inshore subtidal habitats mapped in the biounit (37 151ha), sandy bottoms comprise 18,619ha (50.1%), limestone reefs comprise 9,965ha (26.8%), and seagrass meadows comprise 8,567ha (23.1%). From Eyre Coast Protection District Study Report. Page 65 EYRE REGION – DOUGLAS BIOUNIT Major Benthic Communities • Macroalgal − Along the exposed rocky granite shores and reefs in this region (eg. Greenly Beach, Point Drummond, Rocky Island), subtidal macroalgal communities are dominated by the fucoids, Cystophora monoliformis, C.siliquosa, and C.monolifera and Acrocarpia paniculata and the red algae, Osmundaria prolifera and Haliptilon, in shallow waters (ie. 5m). In deeper waters, rocky reef communities are dominated by Ecklonia radiata and Scytothalia dorycarpa, with species of Cystophora (C.platylobium, C.racemosa, C.moniliformis) as sub-dominants, and also a range of large understorey red algae (eg. Plocamium, Osmundaria, Phacelocarpus, Carpophyllis), encrusting corallines, and green algae (Caulerpa flexilis, C.obscura). • Seagrasses − There are extensive seagrass meadows in this region, due to the dominance of sheltered embayments. Seagrass meadows are dominated by Posidonia angustifolia, Heterozostera tasmanica and Halophila australis and the green alga, Caulerpa cactoides (eg. Port Douglas, Dutton Bay). Coastal and Offshore Islands (or Reefs) − Rocky Islands (North). − Mt Dutton Bay Islands (7 islands). Rivers and Estuaries − Port Douglas (including Kellidie and Mount Dutton Bays): 25-50% of the catchment has been cleared of natural vegetation. This low energy bay consists of intertidal sand/mudflats (0.86 km2), patchy mangroves (3.10 km2) and samphires. MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND 1.1 Biological Coastal and Marine Wetlands of National Importance − The Coffin Bay coastal wetland system has been identified as a wetland of national importance (see ANCA 1996). The Coffin Bay coastal system encompasses the coastline of the Coffin Bay Peninsula, including Avoid Bay and offshore islands, Gunyah Beach, Seven Mile Beach and the waters of Port Douglas (including Yangie, Kellidie and Mount Dutton Bays). Coffin Bay is the largest bay on the Eyre Peninsula, and the second largest estuary in South Australia (after the Coorong), with an overall area of 120 km2 and approximately 60 km of shoreline. The estuary itself is highly significant at a State level in that only 25-50% of its catchment area has been cleared of native vegetation (Bucher & Saenger 1989). All other estuaries in South Australia (except Franklin Harbour) are considerable `developed' with more than 75% of their catchment areas modified. The Coffin Bay wetlands have been identified as areas of international importance for shorebirds by Watkins (1993). The availability of undisturbed coastal cliff habitat and rocky offshore islands makes the area a significant breeding refuge for the Osprey, Pandion haliaetus and White-bellied SeaEagle, Haliaeetus leucogaster (ANCA 1996). The islands support a diversity of wader species and are major breeding sites for terns, gulls and oyster catchers. The area is noted for its breeding population of the Eastern Reef Egret, Egretta sacra, while the beaches are important summering sites for Sanderlings, Calidris alba. Threatened waterbirds in the area include the Hooded Plover, Thinornis rubricollis (Nv, Sv), White-bellied Sea-Eagle (Sv), Osprey (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Musk Duck, Biziura lobata (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), and Eastern Reef Egret (Sr). A total of 63 waterbird and seabirds have been recorded in the region; 22 are listed under international treaties. A total of 18 species breed in the region (see ANCA 1996). Page 66 EYRE REGION – DOUGLAS BIOUNIT − − The substantial areas of marine wetlands in this estuary provide habitats and nursery areas for both estuarine and offshore fish stocks, particularly King George Whiting, Sillaginodes punctata. The size of the estuary and the extent and diversity of its associated wetlands suggest that its contribution to the ecology of the local area would be significant (Bucher & Saenger 1989). Leathery turtles Dermochelys coriacea (Nv, Se) are seen regularly in Port Douglas and Mt Dutton Bay in late summer. A wide range of marine mammals (seals, dolphins and 6 species of whales) are regularly recorded along the Coffin Bay Peninsula and offshore islands between August and December (ANCA 1996). Coffin Bay National Park (Port Douglas) is regarded as one of the few areas of substantial wilderness quality remaining in the settled, more temperate areas of South Australia (Lesslie & Taylor 1983). The southern coastline has striking sandstone cliffs, sandy beaches and excellent views of the offshore islands, while the northern coastline has tranquil bays and the samphire (Sarcocornia blackiana) swamps in Port Douglas. This range of environments supports 148 species of birds, 26 species of reptiles and two or three species of terrestrial mammals although at least eight more species are known to have inhabited the area at the time of European settlement (Preece 1985, Martin 1994). Birds recorded on the cliffs include Rock Parrots, White-bellied Sea Eagles and Ospreys. The sandy beaches are breeding sites for Redcapped Plover (Charadrius ruficapillus), the Pied Oyster-catcher (Haematopus longirostris) and the Hooded Plover (Thinornis rubricollis). The swamps attract large numbers of migratory waders in spring and summer from the Northern Hemisphere. Mt Dutton Bay Islands Conservation Park (Port Douglas) consists of seven small islands in the bay. Although disturbed, they are still areas of biological significance, especially as breeding sites for birds. For instance, a total of nine species of seabirds breed on Rabbit Island, including Little Penguins (Eudyptula minor), Eastern Reef Egrets (Ardea sacra), Pied Oystercatchers (Haematopus longirostris), Sooty Oystercatchers (Haematopus fuliginosus), Silver Gulls (Larus novaehollandiae), Pacific Gulls (Larus pacificus), Caspian Terns (Hydroprogne caspia), Fairy Terns (Sterna nereis) and Crested Terns (Sterna bergii) (Gill 1985a). Eastern Reef Egrets also breed on Goat Island (Gill 1980) while Buff-banded Rails (Rallus philippensis) breed on Rabbit Island. The largest of the Brothers is a major breeding site for Crested Terns, Caspian Terns and Rock Parrots (Neophema petrophila) (Gill 1985b). Single Sooty Terns (Sterna fuscata), which normally breeds only on islands off the Western Australian, Northern Territory and Queensland coasts, have been recorded. The islands are on the Register of the National Estate. − Kellidie Bay Conservation Park has dense thickets of Melaleuca neglecta which line the swamps margin which is an increasingly rare vegetation type on Eyre Peninsula (Preece 1985). The swamps attract several uncommon birds such as the Wood Sandpiper (Tringa glareola), Latham's Snipe (Galinago hardwickii), and the Buff-banded Rail (Rallus phipippensis). The Marsh Harrier (Circus aeruginosus) is also found in swampy areas. − Extensive seagrass meadows. The seagrasses in the Port Douglast represent the second largest areas of seagrass on the Eyre Coast. The sheltered embayments of the Eyre Coast, particularly Streaky and Smoky Bay (ie. Streaky Biounit), and Port Douglas (ie. Douglas Biounit), support extensive seagrass meadows. These extensive seagrass meadows flourish in shallow clear waters, generally in waters less than 15m, and provide the basis for the significant productivity of the coastal regions in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 86,163 ha in Streaky and Smoky Bay, and 8 567 ha in Port Douglas. Together, the seagrasses of the Eyre Coast represent approximately 15% (ie. 1,407 km2) of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Other Areas of Recognised Conservation Significance − Rocky Island (North) Conservation Park: haul out and basking sites of the New Zealand Fur Seal (Arctocephalus forsteri) has been recorded on Rocky (North) (Shaughnessy et al. 1994). Haul out and possibly breeding colonies of the rare Australian Sea Lions (Neophoca cinerea) occur on the Rocky Island (North) (Watts & Ling 1985, Gales 1990). The park is on the Register of the National Estate. Page 67 EYRE REGION – DOUGLAS BIOUNIT 1.2 Physical Geological Monuments − 2 Drummond Point is a "geological monument" of State significance. Features of geological and geomorphological interest include: welldeveloped shore platforms; Archaean Kiana Granite (amongst the oldest rocks in South Australia); and a major mylonite zone. OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries include Southern Rock Lobster, Abalone and Western King Prawn. Marine scalefish fisheries in this region primarily target King George Whiting and is of major State importance. Western King Prawn This biounit is located within the waters of the West Coast prawn fishery, which comprises 3 license holders (ie. Boats). All vessels fish within the waters of this biounit (ie. Fishing Zones 27), the Newland Biounit (ie. Fishing Zone 15), and the Nuyts Biounit (ie. Fishing Zone 8). In 1995/96 and 1996/97 a total of 200,764 and 166,414 kg was caught for this fishery, with a total effort of 3,144 and 2,778 hours, respectively (or 8.84% and 8.22% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster In 1995/96 and 1996/97 a total of 23 and 27 licensed operators fished in the Douglas Biounit (ie. Fishing Zone 27), catching approximately 42,151 and 49,754 kg of lobsters, respectively (or 0.82% and 0.97% of the total catch for Southern Rock Lobster in South Australian waters). Abalone Blacklip Abalone and some Greenlip Abalone is presently commercially harvested within the Douglas Biounit, (ie. MapCode 12A-C, 13A-C, Drummond Point – Frenchman Bluff region), but due to confidentiality constraints these figures are not available. In 1994/95 and 1995/96 a total of 28,620 and 20,285 kg of Blacklip was harvested within this region, and represented 9.2% and 7.3% of the total Blacklip Western Zone catch (or 5.79% and 4.38% of the total catch for Blacklip in South Australian waters). Marine Scalefish Fisheries This biounit represents one of the most significant regions for the marine scalefish fishery in South Australia. During 1995/96 and 1996/97, 63 and 59 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Douglas Biounit (ie. Fishing Zone 27), respectively. License holders expended approximately 2028 and 1815 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 27) represented 2,438 618 kg in 1995/96 and 923,539 kg in 1996/97(or 23.45% and 9.11% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Coffin Bay: 7 unrestricted marine scalefish licenses, 4 Southern Rock Lobster. 2.2 Aquaculture Pacific Oyster farming is the only mariculture industry in this coastal biounit. At present all activity is concentrated in the Port Douglas region, which represents one of the major regions for oyster growing in South Australia. As such, significant activity is present in western Mount Dutton Bay (11 approved leases) and Kellidie Bay (8 approved leases). In addition to the approved leases, another 5 oyster lease applications are pending in this region, all are located at the southern end of Horse Peninsula. Yangie Bay, and sections of Mount Dutton Bay and Port Douglas are presently not considered suitable for aquaculture. The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) proposes the following level of aquaculture development in this region: Page 68 EYRE REGION – DOUGLAS BIOUNIT Farm Beach Policy Area − Frenchman Management Zone (eastern waters of Coffin Bay) – no existing aquaculture. Licenses will considered for 50 ha of shellfish aquaculture (5 R&D permits, 10 ha each). No finfish aquaculture will be considered in this area. − Coffin Bay Peninsula Management Zone (western waters of Coffin Bay) – no existing aquaculture. Licenses will not be considered for aquaculture development within this zone. − − − − − Kellidie Bay Aquaculture Zone (central waters of Kellidie Bay) – 40 ha of oyster culture currently operating and is the maximum area proposed for this zone. Lease areas must not exceed 8 ha and a maximum of 2 ha from existing leases can be relocated within this zone. − Kellidie Bay Zone (remaining waters of Kellidie Bay) - Licenses will not be considered for aquaculture development within this zone. Farm Beach Zone (remaining waters of Coffin Bay, not covered by above) – no existing aquaculture. Licenses will not be considered for aquaculture development within this zone. Port Douglas Policy Area − Kellidie Bay Policy Area Horse Peninsula Management Zone (waters of Port Douglas, adjacent the Horse Peninsula) – existing R&D shellfish aquaculture leases. Licenses will be considered for a maximum of 15ha of oyster culture in this zone (and a maximum of 5 leases will be considered). Point Longnose Management Zone (waters of Port Douglas, south of Point Longnose) – no existing aquaculture. Licenses will be considered for a maximum of 20ha of oyster culture within the zone, but no more than a total area of 110ha of aquaculture development will be considered in the Port Douglas-Coffin Bay-Kellidie Bay-Dutton Bay region. Little Douglas Management Zone (central waters of Port Douglas) – no existing aquaculture. Licenses will be considered for a maximum of 10 ha of oyster culture, but no more than a total area of 110 ha of aquaculture development will be considered in the Port Douglas-Coffin Bay-Kellidie Bay-Dutton Bay region. Port Douglas Zone (remaining waters of Port Douglas, not covered by above) – no existing aquaculture. Licenses will not be considered for aquaculture development within this zone. Dutton Bay Policy Area − Dutton Bay Aquaculture Zone – 40 ha of oyster culture currently operating and is the maximum area proposed for this zone. One lease may be considered for a nursery lease to a maximum of 2 ha. − Lavender Bay Aquaculture Zone – no existing aquaculture. Licenses will be considered for a maximum of 8 ha of oyster culture within this zone. − Bulldog Point Aquaculture Zone – no existing aquaculture. Licenses will be considered for a maximum of 8 ha of oyster culture within this zone. − Dutton Bay North Aquaculture Zone – 4 ha of oyster culture currently operating and is the maximum are proposed for this zone. One lease may be considered for a nursery lease to a maximum of 2 ha. − Salt Creek Aquaculture Zone - 4 ha of oyster culture currently operating and is the maximum are proposed for this zone. − Mount Dutton Zone - Licenses will not be considered for aquaculture development within this zone. Page 69 EYRE REGION – DOUGLAS BIOUNIT Coffin Bay Policy Area − Coffin Bay Zone (waters of Yangie Bay, Coffin Bay, south of Horse Peninsula) – 1 oyster lease currently operating. Licenses will not be considered for aquaculture development within this zone. − No marine-based aquaculture current exists in the Point Sir Isaac to Frenchman Bluff to Drummond Point to Point Sir Isaac region. The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) proposes no aquaculture development in this region: − 2.4 Scientific Research and Education − Drummond Point Policy Area − Drummond Point Zone (ie. inshore waters from Sheringa Beach south to Point Sir Isaac, east to Frenchman Bluff) – licenses will not be considered for aquaculture development in this zone. National and Conservation Parks Fishing − − Convention Beach: beach fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon and Tommy Rough. − Farm Beach: boat fishing. Major species: King George Whiting, Sand Flathead, Tommy Rough and Garfish. − − − − Coffin Bay, Kellidie Bay, Almonta: boat, beach, jetty and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Garfish, Tommy Rough, Snapper and Trevally. Tourism − Coffin Bay: considered an unspoilt area for fishing, watersports and family holidays. It is considered an important wilderness area (Lesslie & Taylor 1983). The `Oyster Walk' at Coffin Bay is a 2.5 km guided tour through native bushland. Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks; and regular research and monitoring of South Rock Lobster field stocks. 2.5 Adjacent Land Use 2.3 Recreation and Tourism − SCUBA diving: Frenchman Bluff and Coles Point are recognised reefs dives and listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The former is a shallow shore dive (down to 12m) suitable for novices, the latter dive (12-20m) via a gutter, is suitable only for experienced divers and perfect weather due to swell conditions. Rocky Island (North) Conservation Park (9 ha). Coffin Bay National Park (28,106 ha). Coffin Bay Conservation Reserve (2,560 ha). Kellidie Bay Conservation Park (1,780 ha). Mt Dutton Bay Conservation Park (12 ha). Agriculture/Industry There is relatively little urban development in this biounit. Most adjacent land not protected as a national or conservation park, is used for agriculture. Urban Centres − Coffin Bay (population 341). This centre is a major tourist destination and hence, its transient population is considerably larger. Coffin Bay also has a permanent coastal mooring facility for 90 recreational craft. Page 70 EYRE REGION – DOUGLAS BIOUNIT 2.6 Significant Cultural and Historical Features 4 AREAS OF HIGH CONSERVATION VALUE IN THE DOUGLAS BIOUNIT Aboriginal Rocky Island (North) − − − 3 Hill Bay, Drummond Point (not dated): an occupation complex consisting of middens and artefact scatters. Has potential for National Estate listing (A. Nicholson, pers.comm.). Although few archeological investigations have been conducted at Coffin Bay, this region has the potential to contain a rich and diverse cultural record (A. Nicholson, pers.comm.). Further, the relatively intact character of the natural habitat significantly increases the integrity of any potential cultural sites. Coffin Bay is also known to contain extensive, stone walled fishtraps (Martin 1988). As a result of its cultural significance, the PALO is presently investigating the possibility of joint management of this region. European Not known. CURRENT CONSERVATION STATUS OF THE DOUGLAS BIOUNIT − Marine Reserves None − Marine Parks None − − Netting Closures Coffin Bay (all waters south of a line from Point Sir Isaac to Frenchmans Bluff). Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change, including not subject to human induced change terrestrial vegetation), ecological (significant breeding site for New Zealand Fur Seals and haul out site for Australian Sea Lions), economic (Southern Rock Lobster, significant area for Blacklip Abalone), national (Register of the National Estate-Rocky Island North Conservation Park), practicality (insulation, compatibility-adjacent to Rocky Island North Conservation Park). Coffin Bay-Port Douglas-Yangie Bay − Prime IUCN Conservation Values: biodiversity, social, rare and endangered species/habitats (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change, including not subject to human induced change terrestrial vegetation), ecological (significant nursery, feeding habitat for economic species – eg. King George Whiting, Western King Prawn, marine scalefish, significant estuarine function, ecological integrity, breeding sites for Rock Parrots, White-bellied Sea Eagles, Ospreys, Red Capped Plover, Pied Oyster Catcher, Hooded Plover, Little Penguins, Eastern Reef Egrets, Crested Terns, Caspian Terns, Fairy Terns, Sooty Terns), economic (tourism, marine scalefish fisheries), social (recreation, aesthetic values), national/international (Wetland of National Importance-Coffin Bay wetland system, international importance for shorebirds, Register of the National Estate-Mt Dutton Bay Islands Conservation Park), practicality (accessibility, insulation, compatibility-adjacent to Coffin Bay National Park, Conservation Reserve, Mt Dutton Bay Islands Conservation Park, Kellidie Bay Conservation Park). Page 71 EYRE REGION – WHIDBEY BIOUNIT IX MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE WHIDBEY BIOUNIT This biounit extends from Point Sir Isaacs to Cape Catastrophe on the southern tip of Eyre Peninsula, and covers an area of 132,689 ha and a coastal distance of approximately 167 km. It is oriented in a generally southwesterly direction into the Southern Ocean. Gunyah Beach (20 km) is an excellent example of transgressive Holocene dunes that extend up to 10 km inland. This beach is also the highest energy, and most dynamic on the Eyre Peninsula. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY The coastline of this biounit faces mostly southwest and is one of the highest wave energy shorelines in Australia, rivalling Canunda in the South-East (Short & Hesp 1984). Open coast sea temperatures vary from a mean summer sea surface temperature of 18oC to a mean winter sea surface temperture of 14oC. The inshore coastal regions are under the influence of seasonal coldwater, nutrient-rich coastal upwellings which occur close to the coast, which can result in an offshore sea surface temperature gradient of 18oC to inshore temperatures of 11oC in inshore areas during the summer months. The major focus of the coastal upwelling appears to extend from Point Sir Isaac (Coffin Bay Peninsula) to Cape Borda (Kangaroo Island) (Wenju et al. 1990) and in part, may be responsible for the very high levels of productivity, seabirds, marine mammals, and marine benthic biodiversity in the region. Recent studies indicate that is a relationship between the upwellings and the pilchard abundance in these areas (Ward & McLeay 1998). 2 GEOLOGY AND GEOMORPHOLOGY13 COASTAL This biounit consists of high Pleistocene dune calcarenite cliffs capped by Holocene clifftop dunes in places, and high energy intermediate-dissipative beaches, backed by very unstable massive Holocene dune transgression usually overlain by Pleistocene dune calcarenite. Large amounts of marine sediment have been blown inland by the west to south-west winds to form some of the widest transgressive Pleistocene dune calcarenite and Holocene dunes in Australia. 13 Groper Bay (Sleaford Peninsula) is an excellent example of the type of steep sand ramps that feed the successive dune transgressions and cliff top dunes. A number of offshore islands occur in this biounit: − Greenly Island and adjacent islets: composed of a crystalline basement. − Four Hummocks: high domed outcrops of crystalline basement of granitic composition. − Perforated Island: granitic headlands and steep cliffs which protect small bays and inlets. The island is composed of crystalline basement with a thick cover of calcareous aeolianite. − Price Island and Liguanea Island: composed of crystalline basement with a cover of aeolianite. − Curta Rocks: two of the islands are crystalline basement with a very flat cover of aeolianite. The others have a very rounded relief. − Williams Island: crystalline basement covered by a thick sequence of calcareous aeolianite. The crystalline basement outcrops on all but the eastern coast where near vertical cliffs of aeolianite rise directly above sea level. There is one embayment on the northern shore where beach sand has been deposited. − Neptune Islands: North Neptune Island is crystalline basement with a cover of calcareous aeolianite with considerable erosion on the southern and western sides caused by heavy seas and strong winds. The three other small islands to the northeast are crystalline basement. The island nearest to North Neptune has a thin cover of calcareous aeolianite. From Eyre Coast Protection District Study Report. Page 72 EYRE REGION – WHIDBEY BIOUNIT − South Neptune Islands: comprise three islands, all of which are crystalline basement. The larger two have an aeolianite cover. − On the southwestern coasts of both, considerable erosion of the aeolianite has occurred. − − − − North and Central Four Hummocks Island). Rocky Island (South). Liguanea Island (Cape Carnot). Curta Rocks, Williams Island (southern Jussieu Peninsula). Neptune Islands: including the North Neptune Islands (4) and the South Neptune Islands (3). Rivers and Estuaries 3 BIOLOGY − Sleaford Mere. Major Habitats − Major intertidal habitats in the region include mostly offshore islands, sandy beaches and rocky shores. MARINE CONSERVATION VALUES 1 − Of the total inshore subtidal habitats mapped in the biounit (43,710ha), sandy bottoms comprise 38,489 ha (88.1%), and reefs comprise 5,221 ha (11.9%). No seagrass habitats have been recorded in the region. SIGNIFICANT BIOLOGICAL AND PHYSICAL FEATURES 1.1 Biological Coastal and Marine Wetlands of National Importance Major Benthic Communities − • Macroalgal − Along the exposed rocky shores, reefs and islands in this region (eg. Point Whidbey, Sleaford Bay, Price Island, Four Hummocks, Liguanea Island), subtidal rocky shore macroalgal communities are dominated by the fucoids, Cystophora monoliformis, C.siliquosa, and C.monolifera and the red algae, Osmundaria and Haliptilon occur in shallow waters (ie. <5m). In deeper waters, rocky reef communities are dominated by Ecklonia radiata and Acrocarpia paniculata with Osmundaria prolifera with species of Cystophora (C.platylobium, C.racemosa, C.moniliformis) as sub-dominants, and also a wide range of large understorey red algae (eg. Plocamium, Phacelocarpus, Carpophyllis, Carpopeltis, Peysonnelia, Sonderopelta) and green algae (Caulerpa flexilis, C.obscura ). • Seagrasses − There are no significant areas of seagrasses within this region, due to the very exposed nature of the coast. Coastal and Offshore Islands (or Reefs) − − − Avoid Bay Islands (including Black Rocks). Greenly Island and adjacent islets. Whidbey Islands (Golden, Price, Perforated, The Coffin Bay coastal wetland system has been identified as a wetland of national importance (see ANCA 1996). The Coffin Bay coastal system encompasses the coastline of the Coffin Bay Peninsula, including Avoid Bay and offshore islands, Gunyah Beach, Seven Mile Beach and the waters of Port Douglas (including Yangie, Kellidie and Mount Dutton Bays). See Douglas Biounit for more information. Offshore Islands of Recognised Conservation Significance − The offshore islands in this region represent some of the most significant breeding sites for the New Zealand Fur Seal (Arctocephalus forsteri) in Australia. The largest breeding colonies of fur seals in South Australia occur on the South and North Neptune Islands and together have been recently estimated at almost 16,800 individuals, or 61% of the total SA population (27,616) or 49% of the Australian population (34,700) (Shaughnessy et al. 1994). In this biounit, breeding colonies of fur seals have been recorded on South Neptune (1974 pups, estimated population 9,673), North Neptune (1,472 pups, estimated population 7,212), Liguanea Island (555 pups, estimated population 2,719), Rocky (South) Island (75 pups, estimated population 367), Four Hummock Island (75 pups, estimated population 367), Greenly Island (11 pups, estimated population 54) and Little Hummock Island (7 pups, estimated population 34). Haul Page 73 EYRE REGION – WHIDBEY BIOUNIT out and basking sites include South Neptune Island (South), Low Rocks, Williams Island, Curta Rocks, Cape Rock, Four Hummocks (South, Mid, North), Rocky (North) Islands (Shaughnessy et al. 1994). − Colonies of the rare Australian Sea Lions (Neophoca cinerea) have also been recorded on many offshore islands in this region. Although breeding takes place at only some of these sites there is considerable mobility between haul out sites. Breeding colonies have been recorded on Liguanea Island (30 pups, estimated population 144) and South Neptune Island (North) (4 pups, estimated population 19). While breeding possibly occurs on Rocky Island (North and South), Greenly Island, North Hummock, Price, East Neptune Islands (Gales 1990). Haul out and basking sites in this region include South Hummock, Central Hummock, Little NE Hummock, Golden, Cape Rock, Curta Rocks, Williams, Low Rocks, West Neptune and North and South Neptune Islands (Watts & Ling 1985, Gales et al. 1994). • Avoid Bay Islands Conservation Park. − This is another important area for birdlife, although only Black Rocks have been surveyed by the National Parks and Wildlife Service. Species include White-faced Storm Petrels, Pelagodroma marina, Little Penguins, and Short-tailed Shearwaters, Puffinus tenuirostris. A pair of White-bellied Sea Eagles, Haliaeetus leucogaster, nest regularly on one of the rocky stacks off Black Rocks; Rock Parrots (Neophema petrophila) are also very common and probably breed here. The islands are on the Register of the National Estate. • Whidbey Islands Conservation Park − Is a group of spectacular and relatively pristine islands. Small numbers of Cape Barren Geese breed on these islands as well as small breeding populations of Short-tailed Shearwaters. Many of the islands are also significant breeding and haul out sites for Australian Sea Lions and New Zealand Fur Seals (see above). Perforated Island, so named by Matthew Flinders for the large hole eroded through the middle of the island, has aeolianite cliffs rising sheer from a water level platform of granite. There are dense population of Southern Bush Rats and large numbers of Short-tailed Shearwaters on the island. The islands are on the Register of the National Estate. • Greenly Island Conservation Park − Is a spectacular granite dome with steep sides plunging straight into deep water. It is split by two large crevasses which effectively break the island up into three blocks. There populations of Bush Rats and Cape Barren Geese on the island. There is also a breeding colony of New Zealand Fur Seals (Shaughnessy 1990) and a possible breeding colony of Australian Sea Lions (Gales 1990). The island is on the Register of the National Estate. • − Rocky Island (South) Conservation Park: A small but significant breeding colony (approximately 367 individuals) of the New Zealand Fur Seal (Arctocephalus forsteri) has been recorded on Rocky (South) (Shaughnessy et al. 1994). Haul out and possibly breeding colonies of the rare Australian Sea Lions (Neophoca cinerea) occur on Rocky Island (South) (Watts & Ling 1985, Gales 1990). The park is on the Register of the National Estate. Other Areas of Recognised Conservation Significance • Lincoln National Park − This park includes most of the Jussieu Peninsula, together with the following offshore islands: Rabbit, Bickers, Owen, Little, Lewis, Hopkins, Smith, Albatross, Curta Rocks and Liguanea. All of the islands support very large breeding populations of Short-tailed Shearwaters (Puffinus tenuirostris). Smith Island supports a breeding colony of the Flesh-footed Shearwater (Puffinus carneipes), discovered only recently in 1982. On Curta Rocks there are large breeding colonies of the White-faced Storm Petrel (Pelagadroma marina). Islands and mainland coast support significant breeding populations of the White-bellied Sea Eagles (Haliaeetus leucogaster) and Ospreys (Pandion haliaetus). Many of the islands in this group support breeding or haul out sites for New Zealand Fur Seals and rare Australian Sea Lions (Neophoca cinerea) (see above). Page 74 EYRE REGION – WHIDBEY BIOUNIT • Sleaford Mere Conservation Park − Is a shallow coastal brackish lake, which contains several small islands. Of particular biological significance is the occurrence of stromatolites, up to one metre across, and also, the existence of a land-locked population of skates. 1.2 Physical Geological Monuments − The coastal outcrops of old Precambrian rocks on southern (and southeastern) Eyre Peninsula are geologically of international significance. Of particular significance is the region from Whalers Way-Fishery Bay to Cape Carnot which consists of spectacular calcreted aeolianite cliffs on a Precambrian metamorphic basement. Cape Carnot itself has been recognised as a "geological monument" of international significance and is also on the Register of National Estate. − Cape Catastrophe: charnockitic rocks. 2 OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries include Southern Rock Lobster and Abalone. Marine scalefish fisheries target King George Whiting. Southern Rock Lobster This biounit represents a significant region for lobster fishing in South Australia. In 1995/96 and 1996/97 a total of 47 and 40 licensed operators fished in the inshore waters of the Whidbey Biounit (ie. Fishing Zone 28), catching approximately 141,100 and 177,186 kg of lobsters, respectively (or 2.76% and 3.46% of the total catch for Southern Rock Lobster in South Australian waters). In contrast, in the offshore southern waters of this biounit (ie. Fishing Zone 38), there is less activity and production. During 1995/96 and 1996/97, a total of 19 and 16 licensed operators fished in the offshore waters of the Whidbey Biounit (ie. Fishing Zone 38), catching approximately 13 783 and 10 796 kg of lobsters, respectively (or 0.27% and 0.21% of the total catch for Southern Rock Lobster in South Australian waters). In the offshore western waters of this biounit (ie. Fishing Zone 26), there is a similar level of fishing activity. During 1995/96 and 1996/97, a total of 20 and 20 licensed operators fished in the offshore western waters of the biounit (ie. Fishing Zone 26), catching approximately 11 751 and 16 699 kg of lobsters, respectively (or 0.23% and 0.33% of the total catch for Southern Rock Lobster in South Australian waters). Abalone The Whidbey Biounit is a major region for both, the Blacklip Abalone and Greenlip Abalone fishery in South Australia. In 1994/95 and 1995/96 a total of 32,064 and 36,168 kg of Greenlip was harvested within this region (ie. MapCode 13D-F, 14A-F, 15A-B, 16A-C, 17A-B, 18A-B Point Sir Isaac to Cape Catastrophe, including Whidbey Isles, Avoid Bay Isles), and represented 14.1% and 16.0% of the total Greenlip Western Zone catch (or 8.51% and 9.66% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 51,828 and 38,563 kg of Blacklip was harvested within this region, and represented 16.7% and 13.9% of the total Blacklip Western Zone catch (or 10.49% and 8.33% of the total catch for Blacklip in South Australian waters). Within this region, some abalone is also harvested at the Neptune Islands. In 1994/95 and 1995/96 a total of 7,317 and 687 kg of Greenlip was harvested around the Neptune Islands (ie. MapCode 17C), and represented 3.2% and 0.3% of the total Greenlip Western Zone catch (or 1.94% and 0.18% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 1041 and 0 kg of Blacklip was harvested within this region, and represented 0.3% of the total Blacklip Western Zone catch in 1994/95 (or 0.21% of the total catch for Blacklip in South Australian waters). Marine Scalefish Fisheries This biounit, particularly the offshore waters (ie. Fishing Zone 38), represents a significant region for fin fishing in South Australia. During 1995/96 and 1996/97, 24 and 21 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the inshore waters of the Whidbey Biounit (ie. Fishing Zone 28), respectively. License holders expended approximately 631 and 529 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 28) represented 39,327 kg in 1995/96 and 78 148 kg in 1996/97(or 0.38% and 0.77% of the total catch for the marine scalefish fishery in South Australian waters). Page 75 EYRE REGION – WHIDBEY BIOUNIT In the offshore southern waters of this biounit (ie. Fishing Zone 38), there is less activity and production. During 1995/96 and 1996/97, a total of 12 and 16 licensed operators fished for 371 and 346 days in the offshore waters of the Whidbey Biounit (ie. Fishing Zone 38), catching a total of 352,473 and 310,781 kg, respectively (or 3.39% and 3.07% of the total catch for the marine scalefish fishery in South Australian waters). In the offshore western waters of this biounit (ie. Fishing Zone 26), there is a significantly reduced level of fishing effort and productivity. During 1995/96 and 1996/97, a total of 9 and 13 licensed operators fished for 204 and 331 days in the offshore western waters of the biounit (ie. Fishing Zone 26), catching a total of 150,812 and 196,324 kg, respectively (or 1.45% and 1.94% of the total catch for the marine scalefish fishery in South Australian waters). − Farm Beach: boat fishing. Major species: King George Whiting, Sand Flathead, Tommy Rough and Garfish. Tourism − Neptune Islands: well known as an area for filming and watching White Sharks. The islands are generally reached by boat charter. − Offshore islands: popular sites for SCUBA diving and fishing, including the collecting of Abalone and Southern Rock Lobster. − Whalers Way: contains some of the most accessible, dramatic and beautiful coastal scenery in South Australia. The variety of coastal scenery includes cliffs, caves, crevasses, blowholes and beaches. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: 2.4 Scientific Research and Education − Coffin Bay: 7 unrestricted marine scalefish licenses, 4 Southern Rock Lobster. − Researchers from the NPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies in this region, particularly on offshore islands such as the Neptune Islands. − The Neptune Islands is becoming well-known, both nationally and internationally as one of the major sites in the world for research into White Sharks (Carcharodon carcharias). There is presently an ongoing tagging project being conducted jointly by fisheries researchers and researchers from the international, Cousteau Society. − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone, Southern Rock Lobster, Western King Prawn, and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks; and regular research and monitoring of South Rock Lobster field stocks. 2.2 Aquaculture No marine-based aquaculture current exists in the Point Sir Isaac to Cape Catastrophe region. The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) proposes no aquaculture development in this region: Avoid Bay Policy Area − Avoid Bay Zone (Point Sir Isaac to Shoal Point, including Avoid Bay Isles, Whidbey Isles) – licenses will not be considered for aquaculture development in this zone. Cape Carnot Policy Area − Cape Carnot Zone (Shoal Point to Cape Catastrophe, including Liguanea Island) licenses will not be considered for aquaculture development in this zone. 2.3 Recreation and Tourism Fishing − Convention Beach: beach fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon and Tommy Rough. 2.5 Adjacent Land Use National and Conservation Parks − Coffin Bay National Park (28,106 ha). − Avoid Bay Islands Conservation Park (16 ha). Page 76 EYRE REGION – WHIDBEY BIOUNIT − − Ellis’ (which has been located); the `Amelia’ which is located in Avoid Bay; the HMS `Investigator’ cutter near Cape Catastrophe; and possibly one or two whaler’s anchors in Fishery Bay. Whidbey Islands Conservation Park (271 ha): includes, from the Coffin Bay Peninsula, Golden, Price, Perforated, North and Central Four Hummocks Island. Greenly Island Conservation Park (190 ha). − Rocky Island (South) Conservation Park (4 ha). − Lincoln National Park (29,060 ha): includes most of the Jussieu Peninsula, together with the following offshore islands: Rabbit, Bickers, Owen, Little, Lewis, Hopkins, Smith, Albatross, Curta Rocks and Liguanea. − Lincoln Conservation Reserve (308 ha). − Sleaford Mere Conservation Park (697 ha). Agriculture/Industry 3 − Marine Reserves None − Marine Parks None − Netting Closures None. 4 There is no urban development in this biounit. Most adjacent land not protected as a national or conservation park, is used for agriculture. Urban Centres None. CURRENT CONSERVATION STATUS OF THE WHIDBEY BIOUNIT AREAS OF HIGH CONSERVATION VALUE IN THE WHIDBEY BIOUNIT Coffin Bay National Park-Avoid Bay-Avoid Bay Isles − − The Lincoln National Park is significant in the history of South Australian exploration through its association with the voyage of Matthew Flinders in 1802. A memorial on Stamford Hill in the park commemorates Flinders' visit to the area while the Cape Catastrophe, Memory Cove area was the scene of the most tragic incident of Flinders' circumnavigation of Australia. − An old whaling station is located at Sleaford Bay. Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, aesthetics (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change, including not subject to human induced change terrestrial vegetation), ecological (ecological integrity, significant breeding site for New Zealand Fur Seals and Australian Sea Lions, breeding/roosting sites for White-faced Storm Petrels, Little Penguins, Short-tailed Shearwaters, White-bellied Sea Eagles, Ospreys, Rock Parrots, Red Cap Plover, Pied Oyster Catcher, Hooded Plover), economic (Southern Rock Lobster, significant area for Blacklip Abalone), social (aesthetic values, historic shipwrecks-`Amelia’) national (Wetland of National Importance-Coffin Bay wetland system, international importance for shorebirds, Register of the National Estate), practicality (insulation, compatibility-adjacent to Coffin Bay National Park, Conservation Reserve and Avoid Bay Islands Conservation Park). Shipwrecks Whidbey Islands − 2.6 Significant Cultural and Historical Features − Aboriginal Not known. European − As yet, no shipwrecks within the State waters of southern Eyre Peninsula have been declared historic (under the Historic Shipwrecks Act 1981). However, three shipwrecks and some whaler’s anchors older than 75 years are located in Commonwealth waters and are protected under the Commonwealth legislation (ie. Historic Shipwrecks Act 1976): the `Mary − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category 1A). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (breeding and haul out sites for New Zealand Fur Seals-Rocky South, Four Hummock, Little Hummock, breeding and haul out sites for Australian Sea Lions-North Page 77 EYRE REGION – WHIDBEY BIOUNIT Hummock, South Hummock, Central Hummock, Little NE Hummock, Price, Golden, Cape Rock, breeding sites for Cape Barren Geese, Shorttailed Shearwaters, Southern Bush Rat), economic (Southern Rock Lobster, Blacklip Abalone), national (Register of the National Estate-Whidbey Islands Conservation Park), practicality (insulation, compatibility- adjacent to Whidbey Islands Conservation Park). Greenly Islands − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category 1A). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (breeding site for New Zealand Fur Seals and Australian Sea Lions, breeding sites for Little Penguins, Fairy Tern, Short-tailed Shearwater, roosting sites for White-bellied Sea Eagle, Cape Barren Geese, Southern Bush Rat), economic (Southern Rock Lobster), national (Register of the National Estate), practicality (insulation, compatibilityadjacent to Greenly Islands Conservation Park). Rocky Island (South) − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (significant breeding site for New Zealand Fur Seals and haul out site for Australian Sea Lions), economic (Southern Rock Lobster, Blacklip Abalone), national (Register of the National Estate), practicality (insulation, compatibility-adjacent to Rocky Island South Conservation Park). Lincoln National Park-Thorny Passage − Prime IUCN Conservation Values: rare and endangered species/habitats, aesthetics, biodiversity, cultural values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monument – Cape Catastrophe, Memory Cove, Cape Donington), ecological (significant breeding and haul out sites for New Zealand Fur SealsLiguanea Island, Low Rocks, Albatross Island, Williams Island, Curta Rocks, Cape Rock, breeding and haul out sites for Australian Sea Lions-Liguanea Island, Curta Rocks, Cape Rock, Williams, Smith, Little, Hopkins, Lewis, Thistle, Albatross Islands, White Shark populations, breeding sites for Short-tailed Shearwater, Flesh-footed Shearwater, Whitefaced Storm Petrel, White-bellied Sea Eagle, Ospreys), economic (tourism-dive and fishing charters, significant area for Greenlip Abalone, Blacklip Abalone, Southern Rock Lobster), social (recreation, aesthetic values, whaling stations-Thistle Island, Sleaford Bay, Memory Cove, historic shipwrecks-`Investigator’), national (national importance of breeding colonies of New Zealand Fur Seals and Australian Sea Lions, Register of the National Estate-Lincoln National Park), practicality (accessibility, insulation, compatibility-adjacent to Lincoln National Park, Sleaford Mere Conservation Park). Cape Carnot-Cape Wiles-Fishery Bay − Prime IUCN Conservation Values: social, aesthetics, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monument), ecological economic (tourism, Southern Rock Lobster), social (Whalers Way-very high aesthetic coastal values, recreation), national/international (Register of the National Estate, Geological Monument of International Significance-Cape Carnot). Page 78 SPENCER GULF REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF SPENCER GULF MARINE BIOGEOGRAPHY 1. 2. 3. 4. 5. Spencer Gulf Oceanography Climate Coastal Geomorphology and Landforms Biology MARINE CONSERVATION VALUES 1. 2. 3. Significant Biological and Physical Features Significant Cultural and Historical Features Current Conservation Status of Spencer Gulf BIOUNITS 1. 2. 3. 4. 5. 6. 7. 8. 9. Jussieu Dutton Franklin Yonga Winninowie Tiparra Wardang Pondalowie Gambier Page 79 SPENCER GULF REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF SPENCER GULF MARINE BIOGEOGRAPHY 1 SPENCER GULF Spencer Gulf falls within the coastal geomorphological region known as the Gulfs Province (Short et al. 1986). This region extends from Cape Catastrophe, on the south eastern tip of Eyre Peninsula, to Rapid Head on the Fleurieu Peninsula, and includes South Australia's other large sheltered gulf ecosystem; Gulf St Vincent. Within these sheltered gulf waters occur some of the largest temperate seagrass ecosystems in the world. The sheltered waters also provide an ideal habitat for extensive, intertidal forests of the Grey Mangrove, most of which occur in this region. Together, these coastal ecosystems are of immense ecological and economic importance, providing the essential basis for much of South Australia's commercial and recreational fisheries. The coastal areas of the gulfs however, also support the major urban and industrial cities of South Australia. Historically, this province is also of the greatest maritime significance, reflecting essentially the early European settlement of this region. However, present and future urban and industrial activity in this province, also places this region under the greatest threat from human activity. 1.1 Biogeography of Spencer Gulf Along the southern coast of Australia, marine biogeographers recognise a major biogeographic region, known as the Flindersian Province, which extends from south-west Western Australia to southern New South Wales and includes the waters of Victoria and Tasmania. Within this broad region, the coastal waters of the Great Australian Bight are recognised as warm to cool temperate (in contrast to the cold temperate waters of the southeast of Australia, west of Robe). A complete physical and ecological biogeographic description of the Eyre, Spencer Gulf and Northern Spencer Bioregions, including marine fauna and flora, has been described by IMCRA (1997). Based on coastal geology, wave climate, and coastal orientation, (Short et al. 1986), identified the following coastal geomorphological regions (or subprovinces) for the Spencer Gulf region: 1 2 3 4. 5 6 Based on patterns of biogeography and marine habitats (and also, existing coastal geomorphological classifications), a total of 10 marine biounits have been recognised for the Spencer Gulf region: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 2 Within the Flindersian Province, the Spencer Gulf region (including the Sir Joseph Banks, Gambier and Neptune Isles) encompasses 3 well-defined, finer-scale biogeographical regions: the Eyre Bioregion (which extends from Point Labatt to Arno Bay, and Cape Borda to West Cape); the Spencer Gulf Bioregion (which extends from Arno Bay to Corny Point, and Shoalwater Point to Point Reilly); and the Northern Spencer Gulf Bioregion (which extends from Shoalwater Point to Port Augusta, to Point Reilly) (IMCRA 1997). Southwest Spencer Gulf Subprovince (from Cape Catastrophe to Salt Creek, Tumby Bay, 191 km). Southern Spencer Gulf Subprovince (from Salt Creek to Germein Point, 114 km). Central Spencer Gulf Subprovince (Germein Point to 40 km north of the Hd of Mcgregor boundary, Whyalla, 61 km). Northern Spencer Gulf Subprovince (from Whyalla to Tickera). Wardang Subprovince (from Tickera to Point Turton, 170 km). Formby Bay Subprovince (from Point Turton to West Cape, 80 km). 2.1 Jussieu Biounit Dutton Biounit Franklin Biounit Yonga Biounit Wininnowie Biounit – Tiparra Biounit Wardang Biounit – Pondalowie Biounit Banks Biounit – Gambier Biounit OCEANOGRAPHY Wave Climate Wave energy in Spencer Gulf ranges from moderate at the mouth of the gulf, to very low in the upper regions. Overall, the gulf is a very sheltered ecosystem, subject to very low to low wave energy regimes. Page 80 SPENCER GULF REGION Tides in Spencer Gulf are semi-diurnal with spring ranges of 3.1 m at Whyalla, 3.5 m at Port Pirie and 3.9 m at Port Augusta. There are also considerable changes in mean sea level caused by barometric pressure variations and wind stress, with periods of between 1 and 365 days. These mean sea-level oscillations are relatively slow and can, therefore, penetrate into the northern regions of Spencer Gulf, potentially increasing astronomical tides by over 2 m. Storm surges of up to 1 m are also possible due to the effects of strong winds. These effects become more pronounced in the upper gulf waters due to a `funnelling effect'. In both Spencer Gulf and Gulf St Vincent, a regular period of minimal tidal movement occurs, called a `dodge tide'. In Spencer Gulf, this occurs fortnightly (Gostin et al. 1984). 2.2 CLIMATE The climate of Spencer Gulf is typically semi-arid or `Mediterranean' and as such, is characterised by hot, dry summers and cool, moist winters. It is largely influenced by mid-latitude anticyclones or high pressure systems which pass from west to east across the continent. Winter generally brings southerly to southeasterly winds and low pressure systems which travel across the Southern Ocean between 40 and 50oS, bringing frontal activity and rain. Summer brings northerly to northwesterly winds. Spencer Gulf itself has an ameliorating effect on the coastal regions, producing more temperate weather. The prevailing wind patterns are also influenced by the gulf. Most rainfall falls during winter, however it varies considerably with latitude, from approximately 500 mm in the south to less than 300 mm in the north. Water Temperature and Salinity Spencer Gulf is a hypersaline-high water temperature ecosystem, also referred to as a `reverse estuary', because waters of highest salinities and temperatures occur at the `head' or upper reaches of the gulf, rather than near the open ocean. Salinity and temperature ranges increase from 42.044.8%. and 11.0-240C, at Point Lowly, to 43.248.6%. and 260C, respectively, near Port Augusta (Johnson 1981). This salinity increase is essentially a result of evaporative and mixing processes. Across the entrance of the gulf, salinity and temperature values also vary annually and seasonally, between 35.7 and 37.3%. and 13.00C and 18.00C, respectively. This results in an increase in salinity and temperature from west to east across the entrance of Spencer Gulf (Bullock 1975, Bye & Whitehead 1975). 2.3 3 Currents In Spencer Gulf, a northward flowing current originating from the Bight region enters the western side of the gulf. Branches of this northward flowing current are deflected southward in the Tiparra Reef area, forming a southward flowing counter current along the opposite shore. This counter current generally has higher salinities, resulting in the salinity gradient found at the entrance of the gulf. 4 COASTAL GEOMORPHOLOGY LANDFORMS AND The east coast of Eyre Peninsula is considerably different to the west, being lower and sheltered within Spencer Gulf (see Short et al. 1996, for review). The coast is backed by plains underlain by alluvium and alluvial fans, with the same alternations of headland and bay that occurs on the west coast. The rocky headlands typically consist of exposed Precambrian crystalline rocks, while the beaches have coastal dunes developing behind them. The lower or southern sections of Spencer Gulf, in particular, is highly variable in coastal morphology, and is subdivided by 5 large embayments (Boston, Proper, Porter, Louth, Peake) and 2 large peninsulas (Bolingbroke, Jussieu). Within Spencer Gulf waters there are 31 offshore islands, half of which occur in the Sir Joseph Banks Group near Port Lincoln. The remainder are located between Thistle Island, the largest of the Eyre Peninsula islands (40 km2), and the mainland. In many places shell beds and typical sandy beach deposits are found well above present day high water mark, indicating a period when sea level was higher than it is today. On the west coast of Yorke Peninsula a well marked raised beach is found at Point Brown. In both gulfs, the major tidal currents carry fine, suspended sediment which settle out in the upper reaches, effectively creating very large sedimentary basins. Page 81 SPENCER GULF REGION The west coast of Yorke Peninsula is more irregular than the east, and consequently a few more bays have developed at Moonta Bay, Port Victoria and Hardwicke Bay. Cliffs are not common, although resistant headlands composed of hard granitic rocks do occur at Pearce Point and along the west coast of Wardang Island. A series of beach dune ridges built up during former high still stands of the sea are particularly well developed east of Point Turton and also near Port Victoria and Cape Elizabeth. There are even more extensive ridges on the northern coast of the foot. The coasts along the `foot' of Yorke Peninsula show strong evidence that vigorous erosion is occurring, due primarily to strong prevailing winds and associated storm waves coming from the Southern Ocean. The influence of bedrock on landscape development can be clearly seen, and all the prominent headlands are formed of hard resistant granitic rocks eg. Corny Point, Daly Head and Point Yorke. 5 5.1 BIOLOGY General Marine Ecology The large, sheltered, tidal, reverse estuary of Spencer Gulf , supports some of the most extensive seagrass, mangrove and tidal saltmarsh communities in South Australia (Edyvane 1995). A diverse range of coastal and habitats are represented within Spencer Gulf, including: extensive forests of the grey mangrove and their associated samphire and mudflat habitats in sheltered locations; seagrass meadows; estuaries; intertidal rocky reefs; sandy beaches, subtidal sand patches and “megaripples”; offshore islands; subtidal reefs; and benthic faunal beds on muddy substrates (Edyvane 1995). The major assemblages and communities are broadly distributed according to depth, wave exposure and tidal currents, although local variations occur. Spencer Gulf, particularly the northern reaches, support the most extensive seagrass meadows in South Australia. Approximately 5512 km2 of the seagrass (or 57% of the total area of seagrasses recorded in South Australia), have been recorded in Spencer Gulf region, making it one of the largest areas of temperate seagrass meadows in Australia. These extensive seagrass meadows flourish in the shallow waters of the gulf, generally in waters less than 10m, and provide the basis for the significant productivity of the gulf in terms of fisheries production. The seagrass meadows also support a prolific skeletal biota as infauna and epiphytes, which in turn, provides the carbonate basis for the sediments in the region. The Spencer Gulf region also contains the most extensive areas of mangrove forests in South Australia (Edyvane 1995). Forests occur north of Point Lowly, Port Pirie to Port Broughton, Franklin Harbour, and to a lesser extent at Tumby Bay. Associated with the mangrove habitats are extensive biologically rich mud flats, samphires and seagrasses. 5.2 Intertidal Ecology The intertidal ecology of Spencer Gulf has been summarised in general accounts of the marine intertidal ecology of South Australia, by Womersley and Edmond (1958), and more recently be Womersley (1990). On coasts of moderate wave energy, such as the southern coasts of Spencer Gulf, the intertidal and subtidal fringe of rocky shores is dominated by the brown algae Hormosira banksii and Cystophora spp. On rocky coasts with some wave action, the upper sublittoral zone is dominated by large brown algae, especially Ecklonia radiata, Cystophora subfarcinata, C.retorta, C.polycystidea, C.moniliformis and other species; Caulocystis cephalornithos; Cystoseira trinodis; and Sargassum spp. (such as S.decipiens and S.lacerifolium), with an understorey of coralline algae (e.g. Amphiroa anceps, Cheilosporum elegans), Cladostephus spongiosus and species of Caulerpa. On sandy bottom, below rock areas, the seagrasses Amphibolis and Posidonia often cover very extensive areas as dense, and usually pure, communities. On coasts of slight wave action, with sandy or muddy flats or beaches (ie. the northern parts of Spencer Gulf, excluding rocky outcrops, and several almost land-locked bays, eg. Franklin Harbour), the intertidal and sublittoral fringe is dominated by samphires, the grey mangrove Avicennia marina, the brown alga Hormosira banksii, Pinna razor fish and the filamentous red algae Hypnea and Spyridia. Common algae which occur just below low tide level include Hypnea sp., Spyridia filamentosa, and the green algae Ulva sp., Enteromorpha, Cladophora and Polyphysa peniculus, the latter of which grows epiphytically on old cockle shells. The intertidal forests of the grey mangrove (Avicennia marina) in northern and central Spencer Gulf are the most extensive in South Australia. Mangrove forests occur north of Point Lowly, Port Pirie to Port Broughton, Franklin Harbour, and to a lesser degree near Tumby Bay in Spencer Gulf. Associated with the mangrove habitats are the biologically rich mud flats, samphires and seagrasses. At Redcliff, monospecific stands of Avicennia marina form a low woodland forest extending from mean sea level to spring high-tide level. Progressively higher vegetated zones are a Halosarcia-Sarcocornia (samphire) association, a Sclerostegia-Halosarcia (samphire) association and an Atriplex (saltbush) association (Chinnock 1980). Conspicuous algal mats, which form as a result of sediment trapping by filamentous blue-green algae Page 82 SPENCER GULF REGION are associated with both the mangrove and samphire flora. A variety of marine organisms, mostly gastropods, bivalves, polychaetes and crustaceans, live in and on the mangrove mud, including a newly described species of barnacle (Bayliss 1994). 5.3 Subtidal Ecology1 Spencer Gulf has a wide variety of subtidal benthic habitats, from the invertebrate-dominated muddy benthic environments (fringed with extensive mangrove ecosystems) in much of the far northern gulf, to the seagrass meadows of various densities, sand patches, and algal-dominated platform reefs scattered throughout the central and southern parts of the gulf. Much of southern Spencer Gulf, such as the foot of Yorke Peninsula, comprises strong seasonal currents, which support great abundance and diversity of reef floral species (Edyvane and Baker 1996). Mixed substrates of calcareous reef and sand are found in some areas, supporting both seagrass meadows and algal forests, such as Daly Head (south-eastern Spencer Gulf -Yorke Peninsula) and Port Neill (middle western Spencer Gulf). Calcareous reef is also a dominant benthic feature at Wardang Island and Point Riley, in the upper middle part of eastern Spencer Gulf. Small patches of flat platform reef with overlying sand occur from Shoalwater Point to Arno Bay (middle western Spencer Gulf). Heavy calcareous reef also outcrops off Warbuton Point (north of Moonta Bay, eastern Spencer Gulf), and from the Reef Point/Point Pearce area, out to, and including, Wardang Island. South of Wardang Island, platform reef occurs from the coast westwards, and southwards to the eastern end of Hardwicke Bay. Much of the “foot” of Yorke Peninsula comprises heavy calcareous reef (eg. from Daly Head around to Stenhouse Bay). Sandy areas (colonised by seagrass) include much of northern Spencer Gulf (eg. sandy channels off Middle Bank and Two Hummock Point) and the large sheltered embayments of Hardwicke Bay and Port Minlacowie in south eastern Spencer Gulf; and Tiparra Bay. Northern Spencer Gulf The subtidal benthic habitats of northern Spencer Gulf have been the subject of several surveys, the most notable including Shepherd and Branden (1973), Shepherd (1974) and Shepherd (1983a,b). These studies examined the benthic assemblages of the Middle Bank area (Shepherd & Branden 1973), Crag Point (Shepherd 1974), and the Middle Bank Douglas Bank region (Shepherd 1983a, b). The surveys recorded the presence of dense, 1 From Edyvane KS & JL Baker (1996). Marine Biogeography of Spencer Gulf. monospecific stands of seagrasses in the region, including, Amphibolis antarctica, Posidonia australis and P. sinuosa as the main floral components of the benthos, with scattered stands of Heterozostera tasmanica, Halophila ovalis and Caulerpa cactoides between 7 and 10m depth. Several animal assemblages dominated the benthos including a mixed sponge/cnidarian/echinoderm assemblage on rocky and consolidated shelly substrate; a bryozoan/ascidian/sea pen (Lanceopora, Scyozoa, Polycarpa) assemblage in the troughs of sand waves or “megaripples” (Shepherd 1983b), and molluscan aggregations comprising hammer oysters (Malleus) and razorfish (Pinna bicolor), which occurred over a broad depth range (between the intertidal and 16m depth). The benthic flora and fauna of northern Spencer gulf is characterised by a significant and very distinctive relict tropical element (Shepherd 1983, Edyvane 1995). For this reason it has been identified as a distinctive biogeographical region, known as the Northern Spencer Gulf Bioregion (Edyvane & Baker 1995, IMCRA in press). Although most of the algal species recorded in northern Spencer Gulf have intermediate warm to cool temperate affinities (occurring throughout the southern Australian region), some algal species, such as the brown macroalgae Hormophysa triqueta and Sargassum decurrens, are distinctly tropical and sub-tropical in distribution (Shepherd 1983). Notwithstanding, other algal species, such as Asparagopsis taxiformis and Platysiphonis mutabilis, appear to have distinct warm temperate affinities, occurring only westward of the South Australian Gulfs. In addition to these species, Beanland & Woelkerling (1982) recorded a further four algal species, with tropical affinities, on mangrove pneumatophores. Shepherd (1983), in his survey of northern Spencer Gulf, also recorded a number of coelenterates of special interest. These included: Echinogorgia sp. and Scytalium sp. which appear to be endemic in upper Spencer Gulf (Grasshoff 1982, Shepherd 1983); Virgularia mirabilis, a cosmopolitan species, known in South Australia only from this region (Utinomi & Shepherd 1982, Shepherd 1983); and Telest multiflora, a tropical species, which has been recorded only from mid and upper Spencer Gulf in southern Australia (Verseveldt 1982, Shepherd 1983). In addition, the ascidian, Sucozoa pedunculata is known in southern Australian only from upper Spencer Gulf and Investigator Strait (Kott 1972, 1975). These last four species except for V.mirabilis, appear to have tropical affinities suggesting that isolated populations are confined to Gulf waters (Shepherd 1983). In addition, Shepherd (1983) recorded a number of Page 83 SPENCER GULF REGION species in other phyla newly or not yet described, which are known only from upper Spencer Gulf region. They include the bryozoan, Bugula sp., a flatworm, Ancoratheca australiaensis and an opisthobranch, Discodoris. Further, the ophiuroid, Amphiura trisacantha is apparently rare elsewhere (Baker & Devaney 1981). Recent discoveries of other rare fauna of essentially tropical affinity include the first Australian records of Pisione and Hesionura polychaetes in Spencer Gulf (HartmannSchroeder and Parker 1990a and b). Northern Spencer Gulf also supports the most extensive seagrass meadows in South Australia (Edyvane 1995). Approximately 4140 km2 of seagrass have been recorded in northern Spencer Gulf (north of Point Reilly), which represent 75% of the total area of seagrass recorded in South Australia, and 43% of the total area of seagrass recorded in South Australia. These seagrass meadows flourish in the shallow waters of the gulf (often less than 10m deep in the northern part of the gulf), and provide the basis for significant fish and shellfish production, including the bulk of the state’s snapper, western king prawn and blue crab catches. Growth of Posidonia species is particularly vigorous, with high leaf blade production and turnover rates (West & Larkum 1979). Shepherd (1983) estimates an annual leaf blade productivity in excess of 9 kg/m2 in shallow water. It is clear that habitats in the sheltered northern part of Spencer Gulf are quite dissimilar in species composition to those in the south. Northern areas comprise mainly sandy and muddy substrates, dominated by the seagrasses Posidonia sinuosa and P.angustifolia, Amphibolis antarctica and Heterozostera tasmanica; and benthic invertebrates, such as razor fish (Pinna bicolor), hammer oysters, sponges and ascidians. Very few large brown algal dominated reefs occur in this northern area. Central and Southern Spencer Gulf In contrast to northern Spencer Gulf, very few systematic subtidal studies have been conducted in the central and southern Spencer Gulf region, apart from a recent survey by SARDI (Edyvane & Baker 1996). However, abalone stock assessment studies carried out by the former SA Department of Fisheries (Branden & Shepherd 1982a, b) provide some habitat notes on the substrate, common algae and principle grazing invertebrates for sites in south western Spencer Gulf, from Port Lincoln to Franklin Harbour, including Thorny Passage. The mixed sand and rock substrates of the central gulf are mainly covered with mixed Sargassum species (such as S. linearifolium, S. heteromorphum, S. lacerifolium), and mixed Cystophora species (such as Cystophora expansa, C. brownii, C. monilifera and C. grevillei), with Lobophora variegata as a dominant understorey covering species. In contrast to northern Spencer Gulf, the reef s in the wave exposed southern and south-eastern areas of Spencer Gulf, such as the foot of Yorke Peninsula, are dominated by a variety of large brown macroalgae, such as Carpoglossum confluens, Seirococcus axilaris, Acrocarpia paniculata, and mixed Sargassum and Cystophora species, as well as an abundant and diverse understorey of green algae; and diverse red algal assemblages comprising, coralline, filamentous, succulent and membranous red algal species. On a bioregional scale, southern Spencer Gulf and the Gambier Isles south of the gulf, are particularly diverse in their floral species composition. A total of 52 red algal species (including 6 species of coralline algae) occur as dominants forming part of the benthic cover at sites in south western Yorke Peninsula, at the base of Spencer Gulf - this diversity of Rhodophyta is greater than that recorded from most other survey locations, apart from macroalgal-rich sites in the south east of South Australia. Similarly, diversity of Sargassum species is high on reefs in southern Spencer Gulf. The south-eastern part of Spencer Gulf, including the coastal reef and islands around the base of Eyre Peninsula (excluding the Sir Joseph Banks Group) is particularly rich in brown and green macroalgae, with a total of 33 and 11 species respectively forming the benthic cover of sampled locations. This diversity of brown and green algae occurring as dominants in southern Eyre Peninsula region, is comparable with that recorded for the south east of South Australia, one of the most phycologically diverse areas of South Australia. Clearly, the southern Eyre Peninsula and the southern Yorke Peninsula have close floral affinities, with a similar number of dominant taxa (95 and 94 respectively) and more than 60% of the percentage cover species in common, including almost all of the dominant Cystophora and Sargassum species found in both regions. A detailed account of the subtidal marine ecology of Spencer Gulf has recently been prepared by Edyvane & Baker (1996). 5.4 Seagrass Ecology Seagrass beds are well developed in Spencer Gulf colonising sandy-muddy areas of tidal flats, and extending several metres deep. Heterozostera tasmanica forms dense and pure masses in thick, firm mud from low tide level down for 3-4 m, with occasional plants as deep as 20 m. Posidonia (tapeweed) extends large distances from about 0.5m below low tide to 20m or so deep. The Posidonia leaves often carry a wealth of epiphytes but only few macroalgae (for eg. Caulerpa Page 84 SPENCER GULF REGION cactoides, C.remotifolia) occur in or adjacent to the beds. Posidonia australis, the most widespread species, grows sympatrically with P.sinuosa and P.angustifolia in the shallower part of their range. P.sinuosa is widely distributed to a depth of 15m in sheltered bays and inlets, either in pure stands or growing sympatrically with P.australis or P.angustifolia. In more exposed areas it may form meadows with Amphibolis spp. P.angustifolia grows subtidally from 2-35 m deep. It frequently grows in deeper water than P.australis. In it's deeper range it is often found in association with Heterozostera tasmanica or Halophila australis and in sheltered positions in it's shallower range in association with Amphibolis antarctica. Amphibolis antarctica grows in moderate to fairly strong water movement, from the uppermost sublittoral zone to 23m. Is an earlier coloniser in denuded areas in Posidonia australis meadows, where rhizomes still remain. Other seagrasses of note in Spencer Gulf include: Halophila australis which grows on sand and mud, from low tide level to 23m deep; Ruppi spp. (R.megacarpa, R.tuberosa); Lepilaena marina which forms extensive low turfs in mid and lower eulittoral zones on sandy mud tidal flats, often growing in association with Ruppia tuberosa and Zostera mucronata; and Amphibolis griffithii which forms pure stands or mixed communities with A.antarctica from low tide to depth of 5m. A.griffithii generally extends into rougher localities and tolerates lower light intensities than A.antarctica. Sedimentologically, the seagrass meadow of the gulf (particularly in the northern reaches) act as a major subtidal carbonate "factory", with high rates of in-situ carbonate production and post-mortem skeletal accumulation (Davies 1970, Patriquin 1972, Gostin et al. 1984). Also trapped are terrigenous and aeolian detrital grains, as well as both terrigenous and calcareous muds. The Corallinaceae are important carbonate producers, particularly Lithothamnium, Jania and Corallina species. Benthic and epiphytic foraminifers are also important contributors to the sediment. Other sessile and vagile epifauna which contribute to bed sediment are encrusting bryozoa, gastropods, hydroids, echinoderms and ascidians. 5.5 Fish While a full description of fish species in Spencer Gulf is not available, the fish species of Eyre Peninsula is relatively well documented (see Glover & Olsen 1985). The marine fish fauna found in the waters surrounding Eyre Peninsula is typical of the Flindersian Province of southern Australian coastal waters (Glover & Olsen 1985). As such, many of the species recorded in South Australian waters, have also been recorded in southern and southwestern Western Australian waters, and to a lesser extent, in the waters of western Victoria and northwest Tasmania. There are some 300 species of known marine fish recorded off Eyre Peninsula down to the base of the continental slope, which represents approximately 67% of the species recorded from all South Australian marine waters (Glover 1982). Most of the species along the Eyre coast tend to be inshore with fairly permanent resident populations. However, there are some regular migratory visitors such as the Australian Salmon and occasional oceanic vagrants such as oceanic Sunfish (Mola sp.), Basking Shark (Cetorhinus maximus), Black Marlin (Makaira indica), and the Lizardfish (Saurida undosquamis). Their presence in these waters can be attributed to the easterly flowing Leeuwin Current (Glover & Olsen 1985). Many sea-connected waterways occur along the east coast of Eyre Peninsula. Marine and primarily marine species, such as the Congolli (Pseudaphritis urvillii), may enter and frequent the estuaries and lower reaches of these and other coastal waterways. Among the native freshwater species, which spend part of their life cycle at sea - the Common Galaxias (Galaxias maculatus) and the Black Bream (Acanthopagrus butcheri), have been recorded in the Tod River. The Common Galaxias has also been recorded in the North Shield Creek, Lake Wangary and a tributary of Little Swamp. Small-Mouthed Hardyhead (Atherinasoma microstoma) have been recorded in the permanent spring-fed saline waters of Lakes Hamilton and Newland, on the west coast south of Venus Bay, while eleven normally marine species of fish have been recorded in Lake Wangary, which has a connection with the sea via Minniribbie Creek. The waters of Spencer Gulf are among some of the most commercially productive in South Australia. The most valuable single species fishery in Spencer Gulf is the Western King Prawn (Penaeus latisulcatus), which accounted for 80.87% of the State's total catch in 1996/97. The marine recreational fishery is renowned for the variety of species which provide abundant and excellent sport for line, spear and big-game fishers. Page 85 SPENCER GULF REGION 5.6 Marine Mammals The offshore islands in southern Spencer Gulf, represent important breeding sites for both, the Australian Sea Lion (Neophoca cinerea) and the New Zealand Fur Seal (Arctocephalus forsteri) in South Australia. Important breeding sites for Australian Sea Lions in this region occur at Dangerous Reef and to a lesser extent, English Island (Sir Joseph Banks Groups), while the Neptune Islands has the largest breeding colonies of New Zealand Fur Seals in South Australia, comprising approximately 51% of the total Australian population. Other islands off the southern Eyre Peninsula have smaller but nevertheless important colonies of Sea Lions and Fur Seals, and breeding also takes place at some of these sites (Watt & Ling 1985). Some 18 species of whales have been recorded in South Australian coastal waters (Aitken 1971). Pilot Whales (Globicephala melaena) enter Gulf St Vincent occasionally and have gone aground on local beaches. The largest recorded mass stranding of whales occurred in 1944 when almost 300 False Killer Whales (Pseudorca crassidens) went aground at Port Prime in Gulf St Vincent (Glover & Ling 1976). Both, the Bottlenose Dolphin (Tursiops truncatus) and the Common Dolphin (Delphinus delphis) are common in Spencer Gulf. 5.7 Seabirds The islands of Spencer Gulf are also home to breeding populations of several species of seabirds protected under the South Australian National Parks and Wildlife Act. These include the Little Penguin, White-faced Storm Petrel, Black-faced Cormorant, Pied Cormorant, Crested Tern, Caspian Tern, Silver Gull, Pacific Gull. Little Penguins breed on Pondalowie Islands (Royston and Middle Islands), Wardang Group (Goose and Green Islands), Wedge Island, Sir Joseph Banks Group (Kirkeby, English, Duffield, Hareby, Roxby, Blythe, Reevesby, Lusby, Partney, and Winceby Islands), and Round Island (Lipson Cove) (Copley 1996). White-faced Storm Petrels have been recorded breeding on Wedge Island and the Sir Joseph Banks Group of islands (ie. Kirkby, Sibsey, Hareby, Langton, Blythe, Dalby, Reevesby, Lusby, Partney, Winceby Islands and almost certainly, Spilsby Island) (Copely 1996). Black-faced Cormorants breed on the Wardang Group (Rocky Islet, White Rocks), Sir Joseph Banks Group (Winceby, Sibsey, English Islands), Dangerous Reef, and Lipson Island (Copley 1996). Pied Cormorants breed on Little Goose Island, Bird Islands Conservation Park, Shag Island (Port Broughton), Fishermans Creek, mangrove creeks of Port Pirie, Weerona Island, Chinaman's Creek, Winceby Island, Franklin Harbour. Silver Gull breeding locations include Pondalowie Islands, Wardang Group (Daly Head Island), Bird Islands, Sir Joseph Banks Group (Marum, Blythe, Duffield, Stickney, Sibsey), Dangerous Reef, Lipson Cove, Tumby Island, Round Island and Cape Donington. Pacific Gull breeding populations have been recorded on Little Goose Island, Bird Island and the Sir Joseph Banks Group (Marum, Reevesby, Langton, Roxby, Duffield, Stickney, Sibsey, English, Kirkeby) and Dangerous Reef. A rare visitor to South Australian waters, the Redtailed Tropic-Birds has also been recorded breeding on South Neptune Island (Copley 1996). Species listed as `vulnerable' under the South Australian National Parks and Wildlife Act, such as the Little Tern and Fairy Tern also breed on the offshore islands and coastal regions of Spencer Gulf. The Little Tern has been recorded at Ward Spit (Point Germein). Recent studies indicate that the Little Tern may realistically be regarded as endangered within South Australia (Copley 1996). Breeding populations of Fairy Terns have been recorded at Lipson Cove, Sir Joseph Banks Group (Kirkby, Langton and Stickney Islands), South Neptune Island and the Islet of North Neptunes. Crested Terns have been recorded breeding on the Wardang Group (Goose, Daly Head and Rocky Islands, Seal Rocks), Bird Islands, Ward Spit, Sir Joseph Banks Group (Kirkby, Winceby, Lipson Island), and the Neptune Islands (Lighthouse Island, South Neptune). Caspian Terns breed on Wardang Island, Bird Island, Ward Spit, Franklin Harbour (Entrance Island), Sir Joseph Banks Group (Kirkby, Blythe, Lusby, Roxby, Partney Islands) and the South Neptune Islands (Copley 1996). Page 86 SPENCER GULF REGION MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND coastal erosion (Scoffin 1971). Seagrass meadows also support a prolific skeletal biota as infauna and epiphytes, which in turn, provides the carbonate basis for sediments in the region. Mangroves 1.1 Biological Relic Tropical Fauna and Flora of Northern Spencer Gulf The benthic flora and fauna of Northern Spencer Gulf is characterised by a significant and very distinctive, relict tropical element (Shepherd 1983) and is nationally recognised as a distinct biogeographical region, known as the `Northern Spencer Gulf Bioregion' (IMCRA 1997). Although most of the algal species recorded in Northern Spencer Gulf have intermediate warm to cool temperate affinities (occurring throughout the southern Australian region), some algal species, such as Sargassum decurrens and Hormophysa triquetra, are nowadays only distributed in tropical and subtropical regions. Northern Spencer Gulf appears to be impoverished in terms of overall species richness, but relatively rich in species which are either endemic or have tropical affinities Extensive Seagrass Meadows Spencer Gulf, particularly the northern reaches, support the most extensive seagrass meadows in South Australia, some of the largest in Australia (Edyvane 1996). These extensive seagrass meadows flourish in the shallow waters of the gulf, generally in waters less than 15m, and provide the basis for the significant productivity of the gulf in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 5,512 km2 in Spencer Gulf, of which 4,138 km2 is located in northern Spencer Gulf (ie. north of Point Riley). Together, the seagrasses of Spencer Gulf represent 57% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the central northern reaches of the gulf (ie. Yonga Biounit, 248,596 ha), in the Tiparra Reef region (ie. Tiparra Biounit, 83,912 ha) and the Port Lincoln region (ie. Jussieu Biounit, 56,956 ha). Seagrass meadows are particularly important for a number of reasons: as primary producers they occupy the base of the food chain; they provide important or “critical” habitats such as nursery, breeding or feeding areas for the juveniles and adults of many fish, crustaceans and other marine animals, including a large number of commercial species (Bell & Pollard 1989, Howard et al. 1989); and their extensive root and rhizome systems stabilise nearshore sediments and sand banks, enhancing coastal water clarity and reducing The Spencer Gulf region contains the most extensive areas of mangrove forests and tidal wetlands in South Australia (and the largest areas of temperate mangroves in Australia) (Edyvane 1996). Associated with the mangrove habitats are the biologically rich mud flats, coastal saltmarshes and seagrasses. Together, mangrove and saltmarsh communities along the South Australian coast total approximately 82,000 ha, with the largest communities occurring in Spencer Gulf (46,000 ha) and Gulf St Vincent (20,000 ha). Other substantial communities occur in lower Spencer Gulf (6,000 ha), on the west coast of Eyre Peninsula (9,000 ha) and on Kangaroo Island (7,000 ha) (DELM 1993). In Spencer Gulf, mangrove forests occur north of Point Lowly, from Port Pirie to Port Broughton, in Franklin Harbour, and to a lesser degree near Tumby Bay. Mangrove forests comprise a single species, the Grey Mangrove, Avicennia marina, which forms a low woodland forest extending from mean sea level to spring high-tide level. Progressively higher vegetated zones are a Halosarcia-Sarcocornia (saltmarsh) association, a Sclerostegia-Halosarcia (saltmarsh) association and an Atriplex (saltbush) association (Chinnock 1980). These tidal wetlands are areas of considerable productivity and represent significant feeding habitats for waterfowl and waders, and also represent key nursery, feeding and breeding areas for many economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Conspicuous algal mats, which form as a result of sediment trapping by filamentous blue-green algae are associated with both, the mangrove and saltmarsh flora. A variety of marine organisms, mostly gastropods, bivalves, polychaetes and crustaceans, also live in and on the mangrove mud, and are a key food source. Productivity The extensive mangrove and seagrass areas of Spencer Gulf, particularly Northern Spencer Gulf, are also areas of very high fisheries production for several commercial fish and crustacean species. In terms of overall fisheries production, the northern reaches of Spencer Gulf (south of Point Lowly) supports the largest Western King Prawn (Penaeus latisulcatus) fishery in the Australia. Some 1500 tonnes of prawns, valued at $20 million, are caught annually in the region, which represents Page 87 SPENCER GULF REGION approximately 75% of the State's total prawn harvest. Northern Spencer Gulf itself provides approximately 45% of the State's marine scalefish catch and more than 45% of the State's blue crab catch, although the bulk of the these catches occurs between Moonta and Ward Spit. The mangrove and seagrass areas of Spencer Gulf, particularly Northern Spencer Gulf, also constitute important nursery areas for several commercial fish and crustacean species caught both locally and in the southern areas of Spencer Gulf. The upper regions of Spencer Gulf are important as spawning or nursery areas for the Western King Prawn as well as for numerous species of scale fish of commercial interest. The size of the estuary and its extent and diversity of its associated wetlands suggest that its contribution to the ecology of Spencer Gulf would be significant (Bucher & Saenger 1989). Coastal Wetlands of National Importance A Directory of Important Wetlands in Australia (ANCA 1996) list the following coastal wetlands of national importance in Spencer Gulf: − − − − Tod River Wetland System Tumby Bay Franklin Harbor Upper Spencer Gulf Mangrove System Shorebirds The Spencer Gulf region has been identified as an area of international importance for shorebirds by Watkins (1993). Australian Sea Lions (Neophoca cinerea) and the New Zealand Fur Seal (Arctocephalus forsteri) The offshore islands in this region represent significant breeding sites for the rare Australian Sea Lions (Neophoca cinerea) and the New Zealand Fur Seal (Arctocephalus forsteri) in South Australia. Breeding colonies of the rare Australian Sea Lion have been recorded on Dangerous Reef (East Rock and West Reef), Albatross, English, and North Islands and Peaked Rocks, while breeding possibly occurs on Neptune (East), Price, Lewis, Smith Rock and Buffalo Reef (Gales 1990, Gales et al. 1994). Haul out and basking sites also occur on Williams, Thistle, Hopkins, Smith, Little, Langton, Low Rocks, Neptune (West), Neptune (North), Neptune (South), and South West Rock (Watts & Ling 1985, Gales 1990). Of particular significance is Dangerous Reef which supports the third largest breeding population of sea lions in the world (SANPWS 1990, Gales 1990, Gales et al. 1994). The largest breeding colonies of fur seals in South Australia and Australia occurs on the Neptune Islands (see Eyre Province). Smaller but nevertheless important breeding colonies however have been recorded on Liguanea, Little Hummock, Four Hummocks, Rocky (South) and Greenly Islands (Shaughnessy 1990). Haul out and basking sites include Cape Rock, Rocky (North) Islands, Curta Rocks, Williams Island, Low Rocks and Albatross Island (Shaughnessy 1990, Shaughnessy et al. 1994). Sir Joseph Banks Group The Sir Joseph Banks group of islands represent a relatively pristine environment and has unique molluscs, important bird colonies and breeding colonies of the Australian Sea Lion. The islands are particularly significant as the most important breeding area for Cape Barren Geese in South Australia. Dangerous Reef Dangerous Reef is one of the three major sites for breeding of the rare Australian Sea Lions in South Australia (along with the Pages and Seal Bay, Kangaroo Island). Sea lions numbers on East, Main and West Reefs vary from a total of 530 recorded in 1982 (Watts & Ling 1985) to 424 sea lions in 1990 (Gales 1990). As such, this area represents the third largest breeding colony in South Australia (after the colonies on the North and South Pages), with an estimated 236 pups produced in 1990 (Gales 1990). Dangerous Reef is also significant as a major research and filming site for the White Shark (Carcharodon carcharias). Tiparra Reef Tiparra Reef is an extensive seagrass-reef shoal system in Moonta Bay, that extends along the western coastline of Yorke Peninsula, from Cape Elizabeth to Warbuto Point and Bird Islands. Like the seagrass-reef shoal system of Orontes Shelf in Gulf St Vincent, the calcreted Pleistocene shell bed forms extensive flat rocky surfaces, or low erosional escarpments and provides excellent habitat for a diversity of marine life, including sponges, ascidians, and reef molluscs, and is also an outstanding mixed fishing ground. The diversity and productivity of the area, particularly on the reefs, is enhanced by the tidal currents of the northern gulf. Tiparra Reef is presently the major commercial fishing ground for Greenlip Abalone (Haliotis laevigata) in South Australia, with catches in the area representing approximately 25Page 88 SPENCER GULF REGION 30% of the total South Australian catch for this species (or 65-80% of the total catch for the Central Zone). A conservation reserve was proposed for the reefs at Cape Elizabeth by the former SA Department of Fisheries in 1980. Offshore Islands All the offshore islands in Spencer Gulf (particularly southern Spencer Gulf) could be considered as biologically significant as they support a rich diversity of flora and fauna, particularly birds and Australian Sea Lions. Other Recognised Significance Areas of Biological In early 1974, the former Department of Fisheries advised the Yorke Coast Protection District Board of six significant areas which were under consideration for declaration as Aquatic Reserves. Areas in the Spencer Gulf region included: (i) Gleesons Landing to Daly Head (for education purposes) (ii) The islands and surrounding waters of Althorpe and neighbouring islands (as a conservation reserve to protect the Blue Groper population) (iii) The reefs at Cape Elizabeth (for conservation purposes) None of these areas has since been declared as Aquatic Reserves. However, Gleesons Landing is now a recognised sanctuary for Southern Rock Lobster. 1.2 Physical Northern Spencer Gulf All of the northern Spencer Gulf can be considered as physically significant owing primarily to its nature as inverse estuary which contributes to the physical properties of the region. The area is also recognised at a global level as a being one of the most significant areas of temperate carbonate production in the world. "Geological Monuments" There are 14 areas of geological significance in Spencer Gulf which are associated with the coastline or offshore waters. These areas have been identified and recognised as "geological monuments" by the South Australian Museum and the Geological Society of Australia and include the following sites: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. Memory Cove Kirton Point (Port Lincoln) Cape Donington Arno Bay "Glensea" (10 km north of Shoalwater Point) Port Hughes - Port Moonta Wardang Island Wardang Island, Cliff Point Port Victoria Point Turton Corny Point Browns Beach Meteor Bay Giles Point Further details of these areas are supplied in the relevant regional biounit descriptions below. 2 SIGNIFICANT CULTURAL AND HISTORICAL FEATURES The following description of Aboriginal and european history in the Gulfs province is necessarily brief and selective. The aim is to give the province a historical perspective with emphasis on coastal and maritime history. Only details of Aboriginal historical and cultural sites that have been published in the available literature are described. Aboriginal sites, objects and remains are protected under the South Australian Aboriginal Heritage Act (1988), and a register of such sites, objects and remains is kept with the Aboriginal Heritage Branch of the South Australian Department of Environment and Planning. 2.1 Aboriginal According to Tindale (1974), the Nauo people probably occupied the southern Eyre Peninsula from Venus Bay, south to Port Lincoln and west to Franklin Harbour. It has been suggested (Schurmann 1879) that the Nauo in the south were closely linked linguistically to the Banggala people. Banggala pressures had caused the Nauo to contract to the southwest - on the northeastern side of the Peninsula, the Banggala were being forced southward to take over Nauo land. Page 89 SPENCER GULF REGION However, the Nauo land of the dead was on islands in Spencer Gulf, while the Banggala located theirs on islands to the west, probably out from Coffin Bay (Angus 1847), implying considerable movement and displacement of local groups must have taken place prior to European contact. It is not known whether the Nauo originally occupied the western area of the peninsula or were forced in that direction by the Banggala. The Yorke Peninsula coast was, in the past, intensively occupied by Aboriginals of the Narungga tribe and important evidence of this occupation is to be found at many places. Most evidence of Aboriginal occupation is to be found in the sand dunes along the west coast of the Peninsula. Amongst the most important areas are in the Cape Elizabeth/Tiparra Springs dunes and in the dunes north of Moonta Bay. Other west coast areas where evidence is know to exist are in the dunes between Port Hughes and Cape Elizabeth and in those south of Port Victoria. Other known areas are at Point Yorke on the South Coast and at Black Point and Tiddy Widdy on the east coast. The latter two areas are of considerable importance, though the Tiddy Widdy dunes have been looted. 2.2 European Early Discoverers The first explorer to touch the South Australian coast was the Dutchman, Francors Thyssen in the `Gulden Zeepard' in 1627. He sailed eastwards across the Bight as far as the Nuyts group of islands, but turned back because of the inhospitable coast. It was more than 150 years later when the Frenchman D'Entrecasteaux sailed eastwards to the Nuyts Archipelago and then to Van Diemen's Land. The exploration and mapping of the coast of Eyre Peninsula began with the Englishman Flinders and his crew who arrived aboard the `Investigator' at Fowlers Bay on 28 January 1802. He proceeded in an easterly direction charting the outline of the Peninsula and naming features after places in his native Lincolnshire, after supporters of the voyage, and from the way the features appeared to him (eg. Smoky Bay). He also named islands after his crew, such as at Cape Catastrophe where the Master of the `Investigator' (Thistle), and seven crewmen were drowned. Memory Cove was so named to commemorate those lost. Following the initial discoverers came whalers and sealers, and before settlement had begun, there was a thriving whaling, sealing and fishing industry. The remains of early sealers' huts and whaling stations may still be seen on some of the beaches and offshore islands. The South Australian Company, in addition to its operations at Encounter Bay on Fleurieu Peninsula, established whaling stations on Thistle Island at the foot of Spencer Gulf and at Sleaford Bay on the tip of Eyre Peninsula. Port Lincoln was founded in March of 1839, and increased settlement and agriculture began on a broader scale in the region. Gulf St Vincent was discovered in March 1802 after Flinders discovered the Yorke Peninsula when he sailed down the western side of it after turning back from the head of Spencer Gulf. Flinders named Spencer Gulf after Earl Spencer, Yorke Peninsula after Charles Philip Yorke, and Gulf St Vincent after Earl St Vincent. All three men were at some stage acting as the First Lord of the Admiralty. Following Flinders, sealers, whalers and land speculators soon settled the coastal areas of the Gulfs. Coastal Ports The chief method of communication between Adelaide and the coastal settlements was by sea. Port Clinton, established in 1863 to supply the mining towns of Moonta and Kadina, was the first of the ports on the Gulf St Vincent coast of Yorke Peninsula. At the minor Gulf St Vincent ports of Port Price, Port Julia, Pine Point, Wool Bay and Coobowie, townships grew up at the landward ends of the jetties constructed for the ketch trade, which dwindled away until the last of the old time vessels ceased crossing the Gulf in the mid 1960s. These jetties are now important reminders of that time and those that remain are now used by tourists, divers and fishers. Port Victoria, in the lee of Wardang Island, became one of the last windjammer ports in the world. It was still being used by sailing ships to load grain right up until the Second World War. Shipwrecks There are a number of shipwrecks located within the Spencer Gulf region. Within the waters of Spencer Gulf, designated wrecks are protected by the (South Australian) Historic Shipwrecks Act 1981. Ten shipwrecks in the gulf have been protected via declarations under this Act. In contrast, wrecks in the waters around Neptune and Gambier Islands are protected under Commonwealth legislation, under the Historic Shipwrecks Act 1976. Under this Act, all wrecks older than 75 years old are granted automatic protection under the Commonwealth legislation, whether designated or not. Page 90 SPENCER GULF REGION Along the Yorke Peninsula coast, nearly a hundred shipping accidents have been recorded from cutters to clippers and steamers. The number of deaths in the accidents has been relatively small. Half of these incidents occurred on the south coast of Yorke Peninsula, from Cape Spencer to Troubridge Shoal. Another three dozen occurred on the west coast from Reef Head to Cape Elizabeth and half of these occurred near Wardang Island and in the harbour of Port Victoria. Port Victoria and Wardang Island are significant for both European heritage with its numerous shipwrecks, and for Aboriginal heritage. It is also important for the contemporary Aboriginal population living in the area as Wardang is owned by the Aboriginal Lands Trust and is leased to the Point Pearce Community Council. Heritage Sites Several European heritage sites in Spencer Gulf are formally listed on State Heritage Register: − − − − 3 Port Germein jetty. Former Point Pearce Aboriginal mission. Lighthouse complex and other structures on South Neptune Island. Lighthouse at Corny Point (also listed on the National Heritage Register). Marine Sanctuaries − Gleesons Landing (350 ha) − Marine Parks None − − − − − − − − − − − − − Netting Closures Port Lincoln (Proper, Boston, Louth, Peake Bays) Tod River Tumby Bay Port Neill Arno Bay Franklin Harbour Northern Spencer Gulf (Douglas Bank) Germein Bay Fisherman Bay Port Victoria Brown's Beach Pondalowie Bay Wedge Island CURRENT CONSERVATION STATUS OF SPENCER GULF Spencer Gulf is one of most well represented in terms of Marine Protected Areas of all the coastal regions in South Australia. As such, 4 of the 13 Aquatic Reserves which have been declared in South Australia, occur in this region. No large, multiple use Marine Parks have been declared in this region. As with other coastal regions in South Australia, the majority of MPAs in Spencer Gulf comprise `netting closures', many of which have generally not been formally recognised as MPAs (see Ivanovici 1985, McNeill 1991). Only one Marine Sanctuary has been declared along this coast (ie. Gleeson’s Landing). This was established for the protection of the Southern Rock Lobster. − − − − Marine Reserves Whyalla-Cowleds Landing (3,230 ha) Blanche Harbour-Douglas Bank (3,160 ha) Yatala Harbour (1,426 ha) Goose Island (54 ha) Page 91 SPENCER GULF REGION – JUSSIEU BIOUNIT X MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE JUSSIEU BIOUNIT This biounit extends from Cape Catastrophe on the Eyre Peninsula, north to Salt Creek (Tumby Bay), and covers an area of 240,439ha and a coastal distance of approximately 191 km (including Boston Island, but excluding other offshore islands). The biounit includes the offshore islands of Thorny Passage (Thistle, Albatross, Hopkins, Smith, Lewis, Little, Grindal, Taylor, Owen), Port Lincoln (Bickers, Boston, Donington, Grantham, Louth, Rabbit), Dangerous Reef, the Sir Joseph Banks Group, Spilsby Island and Tumby Island. 16 (16 Although this biounit is included in the Eyre Coast Protection District by Coast Protection Board, it has not been included in this region in this report. This is primarily because the oceanography of this region is more aligned with that of the Spencer Gulf than the west coast of Eyre Peninsual.) MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This biounit forms the southwestern arm of Spencer Gulf and has an overall easterly orientation. Consequently, it is a zone of low wave energy with prevailing offshore winds. 2 GEOLOGY AND GEOMORPHOLOGY17 COASTAL In summary, the coast of this biounit consists of highly variable morphology controlled generally by the bedrock geology. There is some minor Holocene barrier and sandflat sedimentation along the more exposed sections and embayments, whilst in other areas cliffs and shore platforms form the shoreline. Five large bays (Boston, Proper, Porter, Louth, Peake) and two peninsulas (Bolingbroke, Jussieu) help create a highly crenulate and variable coast. The first coastal region is the East Jussieu Peninsula shoreline which runs north-south for 34 km from Cape Catastrophe to Cape Donington. The shoreline is dominated by the bedrock geology, with predominantly cliffs and shore platforms. Low energy carbonate rich beaches, backed by stable foredunes and rock embankments and fronted by 100-200 m wide sandflats, occur in slight embayments, particularly north of Shag Cove. At Memory Cove a fine grained reflective beach is backed by a single stable foredune underlain by a shingle ridge. 17 The region from Cape Donington to Point Boston is highly crenulate and dominated by Boston Bay and Proper Bay. Proper Bay is a large bedrock controlled embayment with 53 km of shoreline from Cape Donington to Kirton Point and facing northeast. Northerly generated wind waves have induced sparse Holocene sedimentation around the bay shoreline and marginal erosion of the coarse outwash deposits has produced rocky strandflats. Both Tulka Well and Spalding cove act as sinks for the generally southerly longshore drift along the bay shores. Along the southern shore, low energy sandflats front relatively stable beaches which are backed by low stable foredunes. North of Proper Bay is Porter Bay which is fronted by several hundred metres of intertidal sandflats with minimal beach activity. The Boston Bay shoreline extends 22 km (including Boston Island) and its very low wave energy conditions in the southern portion has permitted the development of Port Lincoln. In the higher energy northern end of the bay, occasional swell and wind waves have built a series of shingle ridges, capped by a foredune ridge barrier. There is a Holocene barrier backed by a low Pleistocene barrier which is significant as it is apparently the first Pleistocene barrier deposit south of Whyalla. At North Shields the narrow foredune ridge barrier gives way to a low energy, low cliffed coast. These cliffs composed of unconsolidated outwash material, are actively eroding with up to 10 m of cliff being eroded during the past 30 years. It is likely that a higher energy window exists between Point Boston and Point Maria on Boston Island which concentrates wave energy on North Shields during high wave events. From Eyre Peninsula Coast Protection District Study Report. Page 92 SPENCER GULF REGION – JUSSIEU BIOUNIT Louth Bay is a carbonate rich bay with beach and dune sediments approaching 100% carbonate. The northern portions are more exposed to occasional ocean swell and southerly winds, whilst in the southern region occasional beach ridges are fronted by wide sandflats. Louth Island is scarped with seacliffs and shore platforms on the south side, and a 1km long sand spit extends off the northern side. are common on the north-western portion of some islands. Winceby and Reevesby Islands are particularly noted for the presence of abundant amphibolite, a dark-green metamorphic rock, rich in iron and magnesium silicate minerals. − Thistle Island (Thorny Passage): crystalline basement overlain by calcareous aeolianite. Steep cliffs of calcareous aeolianite rise directly above sea level. On the leeward (eastern) side, recent beach sands have been deposited. Several small lakes exist separated from the sea by a narrow strip of coastal dunes. − Albatross Island, Hopkins Island, Smith Island and Grindal Island: predominantly crystalline basement with a thin layer of calcareous aeolianite. − Lewis Island and Little Island: both aeolianite on crystalline basement. 2 Peake Bay (10 km ) contains small stable barriers that increase in width and elevation to the east and are fronted by wider, deeper sandflats. Their formation is likely to be caused by the increasing exposure to wave and onshore wind energy. The 22 km of coast from around Bolingbroke Peninsula to Cape Eiler is dominated by the Precambrian bedrock which forms the peninsula. Low energy beaches fronted by seagrass covered reefs and sandflats surround most of the coast. In several small embayments reflective beaches are backed by usually single stable foredune barriers and minor backbarrier deposits. Point Bolingbroke is joined to the mainland via a double sided 'tombolo like' barrier. The west-facing barrier is exposed to wind generated waves from Louth Bay and is consequently higher energy with wider, deeper sandflats and minor dune transgression. 3 BIOLOGY Major Inshore Habitats The final region from Cape Eiler to Salt Creek is dominated by Holocene barrier-backbarrier deposits with a cuspate foreland in lee of Tumby Bay. The 15 km long northern barrier consists of a foreland focused on Salt Creek mouth comprising a foredune ridge barrier backed by tidal flats. The low energy southern section is the site of Tumby Bay township which terminates at an inlet fronted by an intertidal ebb tide delta which has been dredged for marina access. South of Tumby, extensive supratidal and intertidal flats (the latter covered by mangrove) back onto two beach ridgeforedune ridge barriers which join as a cuspate foreland. − Major intertidal habitats in the biounit include bays and estuaries (ie. intertidal mudflats), sand beaches and rocky shores. − Of the total inshore subtidal habitats mapped in this biounit (153,526 ha), sandy bottoms comprise 65,921 ha (42.9%), seagrass meadows comprise 56,956 ha (37.1%) and reefs comprise 30,649 ha (20.0%). This biounit is characterised by numerous offshore islands. The following are of geological interest: − − The Sir Joseph Banks Group of islands lie eastward of Louth Bay and include; Winceby, Reevesby, Marum, Partney, Lusby, Kirkby, Blyth, Hareby, Roxby, Langton, Boucaut, Duffield, Stickney, English and Sibsey island. These are low lying islands covered with a marsh-saltbush shrubland. All islands consist essentially of a basement of crystalline rock (ie. granite), overlain by calcareous aeolianite (ie. limestone) and capped, in part, by consolidated dune limestone and recent unconsolidated sand dunes. Many of the islands have well developed beaches, while sand dunes Major Benthic Communities • Macroalgal There is a wide variety of reef communities in this region, due to the wide range of wave exposure and current conditions. Along the exposed rocky granite shores, reefs and islands in this region (eg. Hopkins Island, Taylor Island), subtidal rocky shore macroalgal communities are typically dominated by the fucoids, Cystophora monoliformis, C.siliquosa, and C.monolifera and the red algae, Osmundaria and Haliptilon occur in shallow waters (ie. <5m). In deeper waters, rocky reef communities are dominated by Ecklonia radiata, Seirococcus axillaris and Acrocarpia paniculata with species of Cystophora (C.platylobium, C.racemosa, C.moniliformis) as sub-dominants, and also a Page 93 SPENCER GULF REGION – JUSSIEU BIOUNIT wide range of large understorey red algae (eg. Osmundaria prolifera, Plocamium, Phacelocarpus, Carpophyllis, Carpopeltis, Peysonnelia, Sonderopelta) and green algae (Caulerpa flexilis, C.obscura, C.brownii, C.simpliuscula ). − − • − Along moderate and sheltered coasts (eg. Point Bolingbroke, Louth Island, Taylor Island) rocky reefs are commonly dominated by species of Cystophora (C.expansa, C.brownii, C.monilifera, C.moniliformis), Scaberia agardhii, and species of Sargassum (S.decipiens, S.heteromorphum, S.verruculosum) and understorey species of Dictyotales (eg. Lobophora, Zonaria). Within the Sir Joseph Banks Group, on moderately exposed rocky coasts (ie. Stickney Island), sutidal communities dominated by Ecklonia radiata and mixed fucoids, comprising Sargassum linearfolium, S.paradoxum, S.spinuligerum, S.lacerifolium) with species of Cystophora (C. siliquosa, C.monoliformis, and C.monilifera) as subdominants. The understorey is dominated by Osmundaria prolifera, encrusting and articulated coralline algae (eg. Amphiroa) and the prostrate brown alga, Lobophora variegata. On sheltered coasts, rocky reefs are commonly dominated by species of Cystophora (C.expansa, C.brownii, C.monilifera, C.moniliformis), Scaberia agardhii, Caulocystis ulvifera, and species of Sargassum (S.decipiens, S.heteromorphum, S.verruculosum) and understorey species of Dictyotales (eg. Lobophora, Zonaria) and Botrycladia obovata. Reefs within the island group, typically occur in shallow waters, generally occurring down to 10-12m depth. Seagrasses There are extensive areas of seagrass within this region, due to the large number of sheltered sandy embayments (Proper, Lincoln, Boston, Louth, Peake and Tumby bays). These bays are commonly dominated by Posidonia australis to shallow waters (down to approximately 4m) and are dominated by P.sinuosa and P.angustifolia in deeper waters. Sparse meadows of Halophila australis occur as deep as 23m in the offshore gulf waters. − Seagrass meadows occur throughout the Sir Joseph Banks Group, generally in the lee of islands and in deeper waters (>10m). Sandy sediments dominated by Posidonia sinuosa, P.angustifolia and Amphibolis antarctica in shallow areas. Coastal and Offshore Islands (or Reefs) − Thorny Passage (ie. Thistle, Smith, Hopkins, Albatross, Lewis, Little, Grindal, Taylor, and Owen Islands). − − Bickers, Grantham Islands (Proper Bay). Boston Island (Boston Bay). − Louth Island, Rabbit Island (Louth Bay). − Sir Joseph Banks Group of Islands (including Blyth, Boucaut, Dalby, Dangerous Reef, Duffield, English, Hareby, Kirkby, Langton, Lusby, Marum, Partney, Reevesby, Roxby, Seal Rock, Sibsey, Spilsby, Stickney, and Winceby Islands, and Buffalo Reef, and Buffalo and Smith Rocks). − Tumby Island. Rivers/Estuaries − − Tod River (Louth Bay). First and Second Creek (Tumby Bay). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of Recognised National Importance − The Tod River Wetland System (Louth Bay) has been identified as a wetland of national importance (see ANCA 1996). The area consists of a series of permanent rivers and creeks that act as tributaries for the Tod River, and a tidal estuary associated with wide mud flats and sand flats where the Tod River meets the sea. The Tod Estuary is significant as it is one of the few, true estuarine environments on the Eyre Peninsula (Lloyd and Balla 1986). The rivers provide an important drought refuge for waterbirds and breeding habitat for Page 94 SPENCER GULF REGION – JUSSIEU BIOUNIT other aquatic fauna, while the estuary is a nursery area for a variety of fish species. Some of its fish freshwater native species spend at least part of their life cycle at sea: the Common Galaxias (Galaxias maculatus) and Black Bream (Acanthopagrus butcheri). − − The area is also a drought refuge for local waterbirds and a stop-over point for migratory shorebirds. Threatened species of waterbirds recorded in the area include the Cape Barren Goose, Cereopsis novaehollandiae (Sv) and Musk Duck, Biziura lobata (Sv). A total of 10 species of waterbirds have been recorded in the area. Lloyd and Balla (1986) considered this an area of outstanding environmental value and recommended that it be given status as a wetland reserve. The Spencer Gulf region has been identified as an area of international importance for shorebirds by Watkins (1993). Tumby Bay (Salt Creek) has been identified as a wetland of national importance (see ANCA 1996). Tumby Bay is a large intertidal wetland of extensive saltmarsh and high quality mangrove areas with two main tidal inlet channels (First and Second Creeks). Numerous small drainage channels extend from these creeks throughout the extensive samphire flats. The area provides a good example coastal habitat, which has been considerably reduced in many parts of Eyre Peninsula (ANCA 1996). The area comprises a wide range of habitats including estuarine, supratidal (particularly mangroves and samphires) and marine environments (intertidal and subtidal). The wetland provides large areas of mangrove (12 ha), algae and seagrass habitats where various fish species feed and spawn. Coastal vegetation includes chenopod communities on the sand dunes, mangrove and samphire flats fringing the channels and tidal inlets, with Halosarcia sp. and saltbush in less damp areas. The subtidal region is dominated by dense seagrass meadows, comprising Posidonia australis, P.sinuosa, Halophila ovata and the brown alga, Scaberia agardhii. Threatened species of waterbird include the Eastern Curlew, Numenius madagascariensis (Sv) and the Fairy Tern, Sterna nereis (Sv). A total of 22 waterbird species have been recorded, 5 listed under international treaties. Common bird species include: Black Swan, Australian Pelican, White-faced Heron, and cormorants. Migration stopovers include 5 species of migrant shorebirds. A total of 10 species of fish have been recorded, including an extremely large number of juvenile fish. The Spencer Gulf region has been identified as an area of international importance for shorebirds by Watkins (1993). − Tumby Island Conservation Park: on the Register of the National Estate. Islands of Recognised Conservation Value − The offshore islands in this region represent significant breeding sites for the rare Australian Sea Lions (Neophoca cinerea) in South Australia. Breeding colonies of the rare Australian Sea Lion have been recorded on Dangerous Reef (East Rock and West Reef) (275 pups, estimated population 1,323), Albatross (12 pups, estimated population 58), English (40 pups, estimated population 192), and also, the Gambier Isles (see Gambier Biounit). − Breeding possibly occurs on Lewis, Smith Rock and Buffalo Reef and the Neptune Isles (Gales et al. 1994). Haul out and basking sites also occur on Williams, Thistle, Hopkins, Smith, Little, and Langton Islands, and the Neptune and Gambier Isles (see Gambier Biounit) (Watts & Ling 1985, Gales et al. 1994). Of particular significance is Dangerous Reef which supports the third largest breeding population of sea lions in the world, after the North and South Pages (SANPWS 1990, Gales 1990). − While the largest breeding colonies of New Zealand Fur Seals (Arctocephalus forsteri in South Australia and Australia occurs in this region (eg. Neptune Islands), within this biounit, only haul out and basking sites have been recorded (Albatross Island) (Shaughnessy et al. 1994). − Lincoln National Park. This park includes most of the Jussieu Peninsula, together with the following offshore islands - Rabbit, Bickers, Owen, Little, Lewis, Hopkins, Smith, Albatross, Curta Rocks and Liguanea. All the offshore islands support very large breeding populations of Short-tailed Shearwaters (Puffinus tenuirostris). Smith Island also has a breeding colony of the Flesh-footed Shearwater (Puffinus carneipes), which was first discovered in 1982 (Robinson & Heard 1985). On Curta Rocks there are large breeding colonies of the Little White-faced Storm Petrel (Pelagadroma marina). The islands and the mainland coast also support significant breeding populations of the Whitebellied Sea Eagles (Haliaeetus leucogaster) Page 95 SPENCER GULF REGION – JUSSIEU BIOUNIT and Ospreys (Pandion haliaetus). Many of the islands in this group support breeding or haul out sites for New Zealand Fur Seals and rare Australian Sea Lions (Neophoca cinerea). − Sir Joseph Banks Group Conservation Park. The islands of this park are particularly noted for their bird populations. The islands form an important refuge for the 76 recorded species, of which 22 are known to breed on the islands. They are considered the most important breeding area in winter in South Australia for the Cape Barren Goose (Cereopsis novaehollandiae), supporting a stable breeding population of approximately 1500, out of a State population of 3,500-4,000 (Robinson et al. 1982, Robinson & Delroy 1986). White-faced Storm Petrels breed in their burrows on many of the islands while large breeding colonies of Black-faced Shags (Leucocarbo fuscescens) occur on Winceby and English Islands. The islands are also reknown for significant colonies of rare Australian Sea Lions. Dangerous Reef and English Island are of particular significance as breeding sites, however many of the other islands are used as haul out and basking sites (see above). In order to minimise disturbance to breeding colonies of sea lions and shags, public access is restricted to English Island, Winceby Island, Dangerous Reef, Buffalo Rock, Seal Rock, Buffalo Rocks and Smith Rock (SANPWS 1990). Several species of protected seabirds breed on the islands, including Little Penguins (Kirkeby, English, Duffield, Hareby, Roxby, Blythe, Reevesby, Lusby, Partney and Winceby Islands); White-faced Storm Petrels, which breed in their burrows on many of the islands (Kirkby, Sibsey, Hareby, Langton, Blythe, Dalby, Reevesby, Lusby, Partney, Winceby and Spilsby Islands); Black-faced Cormorants (Leucocarbo fuscescens) (Winceby, Sibsey and English Islands; the `vulnerable' Fairy Terns (Kirkby, Langton and Stickney Islands); Crested Terns (Kirkby, Winceby Islands); Caspian Terns (Kirkby, Blythe, Lusby, Roxby, and Partney Islands); Silver Gulls (Marum, Blythe, Duffield, Stickney, Sibsey Island); and Pacific Gulls (Marum, Reevesby, Langton, Roxby, Duffield, Stickney, Sibsey, English, Kirkeby Islands) (Copley 1996). − Black Tiger Snakes (Notechis ater) are found on Hareby, Roxby and Reevesby Islands. While Reevesby Island sand flats at Moreton Bay contain a variety of seagrasses, molluscs, polychaetes, crustaceans. A variety of birds feed in the shallows of these sand flats such as the Sooty Oyster-Catcher. Zeidler and Gowlett (1985) described seventeen interesting and rare species of marine Mollusca from the Sir Joseph Banks Islands. Some of these include: − Brechites (Foegia) veitchi (a bivalve of the family Clavagellidae) found in sand amongst sparse seagrass and rubble. Commonly found just north of Marum Island and between Winceby Island and Reevesby Island in depths of 6-12m. − Rare species of Myadora pervalida (bivalve of the family Myochamidae). − An uncommon species found in sand patches amongst seagrass Posidonia just north of Marum Island and southeast of Winceby Island is Semele monilis (bivalve of the family Semelidae). − Very rare species of Phalium adcocki found in sand pockets adjacent to reefs (gastropod of the family Cassidae). − Undescribed species of octopus including a very large gelatinous specimen with a 2 m arm span. In addition to the wildlife, one of the greatest assets of the Sir Joseph Banks Group of islands is considered to be its pristine, natural beauty (Robinson et al. 1982). The park is on the Register of the National Estate. − Dangerous Island and Reef. This system of reefs lies approximately 25 km offshore and is one of the three major sites for breeding of the rare Australian Sea Lions in South Australia (along with the Pages and Seal Bay, Kangaroo Island). Surveys since 1975 have revealed a population on these reefs ranging between 10 and 600 animals (SANPWS 1990). In 1990, a total of 424 animals, including 236 pups were recorded on East, Main and West Reefs (Gales 1990).This makes Dangerous Reef the third largest breeding colony for this species in South Australia (after the colonies on North and South Pages). This area is also nationally and internationally recognised for the occurrence of White Sharks (Carcharodon carcharias). Black-faced Cormorants, Pacific Gulls, Silver Gulls breed on Dangerous Island (Copley 1996). Page 96 SPENCER GULF REGION – JUSSIEU BIOUNIT − 1.2 Seagrass Meadows 2 The seagrass meadows of this biounit represent the third largest areas in Spencer Gulf. These extensive seagrass meadows flourish in the shallow waters, generally in waters less than 15m, and provide the basis for the significant productivity of the region in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 5,512 km2 in Spencer Gulf, of which 4138 km2 is located in northern Spencer Gulf (ie. north of Point Riley). Together, the seagrasses of Spencer Gulf represent 57% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the central northern reaches of the gulf (ie. Yonga Biounit, 248,596 ha), in the Tiparra Reef region (ie. Tiparra Biounit, 83,912 ha) and the Port Lincoln region (ie. Jussieu Biounit, 56,956 ha). 2.1 Physical Geological Monuments − Memory Cove: charnockitic rocks. Register of the National Estate. − Kirton Point (Port Lincoln): coastal outcrops. On the Register of National Estate as part of Lincoln National Park. − Cape Donington: palaeodunes and coastal basement platform. On the Register of the National Estate. On the Sir Joseph Banks Group The presence of abundant amphibolite, a darkgreen metamorphic rock, rich in iron and magnesium silicate minerals particularly in Winceby and Reevesby Islands. OTHER VALUES Commercial Fisheries Port Lincoln is the major centre for commercial fishing in Spencer Gulf. Major single species fisheries which operate out from Port Lincoln include: Western King Prawn, Abalone, Southern Bluefin Tuna and the Southern Rock Lobster. There is also an extensive marine scalefish fishery in this region which targets, among other species, Snapper, King George Whiting and Shark. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1811598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster In 1995/96 and 1996/97 a total of 11 and 12 licensed operators fished in the Jussieu Biounit (ie. Fishing Zone 30), catching approximately 7,671 and 3,673 kg of lobsters, respectively (or 0.15% and 0.07% of the total catch for Southern Rock Lobster in South Australian waters). No lobsters were caught during this same period for inshore regions of this biounit, ie. Proper, Boston, Louth and Peake bays, from Cape Donington to Point Bolingbroke (ie. Fishing Zone 31). Abalone The Jussieu Biounit is a major region for both, the Blacklip Abalone and Greenlip Abalone fishery in South Australia. In 1994/95 and 1995/96 a total of 74,076 and 59,262 kg of Greenlip was harvested within this region (ie. MapCode 18C-H, J-L, 19AE, Thorny Passage, Thistle Island, Dangerous Reef), and represented 32.6% and 26.3% of the total Greenlip Western Zone catch (or 19.66% and 15.83% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 15,120 and 16,336 kg of Blacklip was harvested within this region, and represented 4.9% and 5.9% of the total Blacklip Western Zone catch (or 3.06% and 3.53% of the total catch for Blacklip in South Australian waters). Page 97 SPENCER GULF REGION – JUSSIEU BIOUNIT The Sir Joseph Banks Group is not a major area for commercial abalone harvesting, (ie. MapCode 20B). No Blacklip Abalone were harvested from this region (ie. MapCode 20B) during 1994/95 and 1995/96. Greenlip Abalone figures are not available due to confidentiality constraints. Marine Scalefish Fisheries This biounit represents one of the major regions for the marine scalefish industry in South Australia. During 1995/96 and 1996/97, 72 and 69 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the offshore waters of the Jussieu Biounit (ie. Fishing Zone 30), respectively. License holders expended approximately 2,122 and 2,148 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 30) represented 931,386 kg in 1995/96 and 1 716,478 kg in 1996/97(or 8.96% and 16.93% of the total catch for the marine scalefish fishery in South Australian waters). Similarly, fishing activity in the inshore waters of this biounit, ie. Proper, Boston, Louth and Peake bays, from Cape Donington to Point Bolingbroke (ie. Fishing Zone 31) is also high. During 1995/96 and 1996/97, 66 and 50 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the inshore waters of the Jussieu Biounit (ie. Fishing Zone 31), respectively. License holders expended approximately 1,687 and 1,753 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 31) represented 697,608 kg in 1995/96 and 1 195,206 kg in 1996/97(or 6.71% and 11.79% of the total catch for the marine scalefish fishery in South Australian waters). − 2.2 Port Lincoln: 17 Abalone, 26 Western King Prawn, 35 Southern Rock Lobster (working west of Eyre Peninsula, 18 restricted marine scalefish, 71 unrestricted marine scalefish, 5 miscellaneous. − Tumby Bay: 4 restricted marine scalefish, 9 unrestricted marine scalefish. Aquaculture This coastal biounit is a major region of sea-based aquaculture activity in South Australia. At present, this region is the only place in South Australia where commercial Southern Bluefin Tuna farming occurs. In this type of fish "farming" wild-caught juvenile tuna are grown out or fattened to maturity in sea-based cages. There are currently 6 approved 20 hectare lease sites for caged farms in Boston Bay (Port Lincoln), one of which is a tourist farm. Each lease site accommodates a maximum of 6 individual cages. However, there is currently a proposal to increase the number of lease sites in this region to 9 (ie. a maximum of 54 cages). In addition to fish farming, there are presently 2 Pacific Oyster leases in southern Louth Bay, and 2 land-based Abalone farms in Louth Bay which remove waters from Louth Bay. An oyster lease application is currently pending for Proper Bay. The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) proposes the following level of aquaculture development in this region: Louth Bay Policy Area − Louth Bay Management Zone (Point Boston to Peake Point) - licenses will not be considered for intertidal, oyster, mussels or finfish aquaculture development in this zone. Licenses will be considered for a maximum of 50 ha of aquaculture (abalone, finfish) in this zone. − Tod River Management Zone (coastal waters adjacent Tod River estuary) – Licenses will be considered for a maximum of 35 ha of shellfish culture in this zone. − Peake Bay Management Zone (Peake Point to Point Bolingbroke) – Licenses will be considered for a maximum of 30 ha of aquaculture (excluding finfish, oyster or mussel culture). − Rabbit Island Tuna Farming Zone (defined waters west of Rabbit Island) - Licenses will be considered for a maximum of 120 ha of tuna culture within this zone. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Louth Bay: 1 unrestricted marine scalefish. Page 98 SPENCER GULF REGION – JUSSIEU BIOUNIT − Rabbit Island Management Zone (remaining offshore waters from Cape Donington, to Point Boston to Point Bolingbroke) – tuna farming is currently being trialed in this area. Licenses will be considered for a maximum of 80 ha of aquaculture development within this zone. Port Lincoln Policy Area − Bickers Islands Aquaculture Zone – 60 ha of aquaculture (tuna, mussels) leases currently operating in this zone. Licenses will be considered for a maximum of 40 ha of tuna culture and 20 ha of R&D shellfish culture within this zone. − Proper Bay Management Zone – oyster hatchery at Louth Bay. Licenses will be considered for a maximum of 50 ha of R&D shellfish culture and 2 ha of R&D oyster culture within this zone. − Rotten Bay Aquaculture Zone – 28 ha of tuna culture currently operating within this zone. Licenses will be considered for a maximum of 20 ha of tuna culture and 8 ha for a singlecage finfish site for tourism. − Boston Bay Aquaculture Zone – 150 ha of leases (mostly shellfish) currently approved in this zone. Licenses will be considered for a maximum of 150 ha of aquaculture development within this zone, comprising 60 ha of R&D mussel culture, 5 ha of R&D rock lobster, 20 ha for R&D aquaculture, 15 ha tuna farming research, and 50 ha of aquaculture other than rock lobster or mussel culture. − Boston Island East Tuna Farming Zone – 80 ha of leases currently approved in this zone. Licenses will be considered for a maximum of 80 ha of aquaculture development within this zone, comprising 60 ha of tuna culture, and 20 ha of finfish culture. − Boston Island West Aquaculture Zone – 120 ha of tuna culture currently approved in this zone. Licenses will be considered for a maximum of 264 ha of aquaculture development within this zone, comprising 240 ha of tuna culture, 20 ha of finfish culture, and 4 ha of R&D rock lobster culture. − Lincoln National Park Zone – Licenses will not be considered for aquaculture development within this zone. − Port Lincoln Navigation Zone (remaining waters within Port Lincoln) - Licenses will not be considered for aquaculture development within this zone. No marine-based aquaculture current exists in the Thorny Passage region (ie. Cape Catastrophe to Cape Donington). The Lower Eyre Peninsula Aquaculture Management Plan (Aquaculture Group, PIRSA 1997) proposes minimal aquaculture development in this region: Thorny Passage Policy Area − Grindal Island Management Zone (waters of northern Grindal Island and western Taylor Island) – licenses will not be considered for abalone aquaculture development in this zone. A total of R&D permits (maximum area of 2 ha) will be considered for a maximum of 6ha of rock lobster aquaculture in this zone. − Thorny Passage Management Zone (remaining waters of Thorny Passage, from Cape Catastrophe to Cape Donington) - licenses will not be considered for abalone aquaculture development in this zone. One R&D permit (maximum of 3 tuna farm sites) will be considered to investigate the impacts of tuna farming in this zone. There is presently no aquaculture activity in the Sir Joseph Banks region. The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends no aquaculture development in this region: Sir Joseph Banks Policy Area Sir Joseph Banks Zone (waters surrounding the Sir Joseph Banks Group of islands) – zoned to preserve existing values and uses, particularly conservation values. Licenses will not be considered for aquaculture development within this zone. 2.3 Recreation and Tourism Fishing − Port Lincoln - Sleaford Bay: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough and Southern Calamari. Page 99 SPENCER GULF REGION – JUSSIEU BIOUNIT − Tumby Bay: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Garfish, Blue Swimming Crab, Tommy Rough and Southern Calamari. − There is an artificial reef near Port Lincoln (a sunken tug vessel, `Bronze Wing'). the colony is out of synchronisation with the Seal Bay (Kangaroo Island) population (SANPWS 1990). Both populations are presently being studied by researchers from SANPWS. − Dangerous Reef is also becoming recognised, both nationally and internationally, as one of the major sites in the world for research into White Sharks (Carcharodon carcharias). There is presently an ongoing tagging project being conducted jointly by fisheries researchers and researchers from the international, Cousteau Society. − In addition to Dangerous Reef, researchers from the SANPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies in this region, particularly on the offshore islands. − Port Lincoln Marine Science Centre is a cooperative research centre, located on the shore of Kirton Point, Port Lincoln. The Centre is administered by Flinders University of South Australia, and contains research laboratories and facilities for staff and students of the university and also, for lease. The centre currently contains research staff and postgraduate students from the South Australian Research and Development Institute (SARDI) and Flinders University. The Centre at present is currently utilised for research and monitoring of commercial fisheries (such as Abalone, Southern Rock Lobster), and also, sea-based aquaculture (such as the farming of Southern Blue Fin Tuna in Boston Bay). − Other fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Tourism − Offshore islands: the following areas are popular for SCUBA diving and recreational fishing (including Abalone and Southern Rock Lobster) - Hopkins and Thistle Islands, West Bay, Gambier Islands (Wedge Island), Sir Joseph Banks Group of Islands, and the Althorpe Islands. Access to these islands is through charter companies such as Failie Charters, as well as by private vessels. − SCUBA diving: Mittlers Cove (north western corner of Thistle Island), Taylors and Hopkins Island (Thorny Passage), Redbanks Spot 2 (Whalers Way), Wanna (south of Port Lincoln), Snowman (Memory Cove), Donnington Rocks, the shipwreck `Degei’ (northern side of Donnington Island), Tumby Bay jetty are all recognised dive spots in this region and listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). − Dangerous Reef: this reef which lies approximately 25 km offshore, is home to Australia's largest Australian Sea Lion colony and famous for its Great White Sharks. Cruises to the reef depart from the Lincoln Cove Marina. − Lincoln National Park: scenic qualities, wilderness areas, historical areas, camping, fishing, SCUBA diving. − Tumby Bay: camping, fishing. 2.4 − Scientific Research and Education Dangerous Reef is home to the third largest breeding population of Australian Sea Lions in the world (after the colonies on North and South Pages). Surveys since 1975 have revealed a population ranging between 10 and 600 animals. In a 1989 census, a total of 470 animals, including 141 pups were recorded (SANPWS 1990). In 1990, a total of 424 animals, including 236 pups were recorded (Gales 1990). The 18 month breeding cycle of 2.5 Adjacent Land Use National and Conservation Parks − Sir Joseph Banks Group Conservation Park (2,033 ha): all the islands of the Sir Joseph Banks Group, with the exception of Spilsby Island, fall within the park (SANPWS 1990). Reevesby Island, the largest within the park was the centre of agricultural pursuits in the island group prior to their acquisition. Page 100 SPENCER GULF REGION – JUSSIEU BIOUNIT − Tumby Island Conservation Park (35 ha). − Gambier Islands Conservation Park (64 ha): comprises three islands and islets of the Gambier Group, North Island, SW Rocks and Peaked Rocks. Wedge Island, the main island of the Gambier Group is held in freehold title and is run as a tourist resort. − Lincoln National Park (29 060 ha): includes most of the Jussieu Peninsula, together with the following offshore islands - Rabbit, Bickers, Owen, Little, Lewis, Hopkins, Smith, Albatross, Curta Rocks and Liguanea. Agriculture/Industry Apart from land reserved as National or Conservation Parks, most adjacent coastal land in this biounit is developed for agricultural purposes. Of particular note however, are the large shipping facilities which occur off Port Lincoln; the 2 landbased Abalone farms in Louth Bay; and the passenger launch to Boston Island, which is a fullyoperational sheep station. − Memory Cove-West Point and the Lincoln National Park is significant in the history of South Australian exploration through its association with the voyage of Matthew Flinders in 1802. A memorial on Stamford Hill in the park commemorates Flinders' visit to the area while the Cape Catastrophe, Memory Cove area was the scene of the most tragic incident of Flinders' circumnavigation of Australia. − An old whaling station is located on Thistle Island. Shipwrecks − `City of Adelaide' (1854-1954): a Historic Shipwreck declared under the South Australian Historic Shipwrecks Act 1981. The vessel, a steel, hydraulically propelled lifeboat, beached at Porter Bay, Port Lincoln in 1954. In 1985 the hull was removed from Porter Bay and placed within the Axel Stenross Maritime Museum at Port Lincoln. Urban Centres − Port Lincoln (population 11,552). Port Lincoln has a permanent coastal mooring facility for recreational and commercial craft. − Tumby Bay (population 996). 2.6 Features Significant Cultural and Historical Aboriginal − In the Port Lincoln region both, woven wooden fishtraps, located in tidal channels, as well as stone walled traps, have been recorded (Martin 1988). − Point Bolingbroke: Aboriginal fish traps and campsites (Martin 1988). − Billy Light Point: Aboriginal fish trap (Martin 1988). European Page 101 SPENCER GULF REGION – JUSSIEU BIOUNIT 3 − Marine Reserves None − Marine Parks None − breeding colonies of New Zealand Fur Seals and Australian Sea Lions, Register of the National Estate-Lincoln National Park), practicality (accessibility, insulation, compatibility-adjacent to Lincoln National Park, Sleaford Mere Conservation Park). CURRENT CONSERVATION STATUS OF THE JUSSIEU BIOUNIT Netting Closures Port Lincoln (all waters west of a line from Point Bolingbroke to Cape Donnington). − Tod River (all waters of the Tod River and Spencer Gulf within a radius of 200 m of the mouth). − Tumby Bay (waters within a line drawn from a point on the mainland adjacent to Tumby Island to the southern tip of Tumby Island then following the high water mark on the eastern coast to a point on the north eastern side to a point on the mainland 2.5km north of the jetty, also all waters within a 500 m radius of the mouth of Second Creek, south of Tumby Bay). 4 AREAS OF HIGH CONSERVATION VALUE IN THE JUSSIEU BIOUNIT Sir Joseph Banks Group and Dangerous Reef − Prime IUCN Conservation Values: rare and endangered species/habitats, aesthetic values, biodiversity, social values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (ecological integrity, diversity of marine habitats, key breeding sites for Cape Barren Goose, White-faced Storm Petrels, Black-faced Shags, significant breeding and haul out sites for Australian Sea Lions-Dangerous Reef, English Island, Langton Island, Buffalo Reef, Smith Rock, haul out sites for New Zealand Fur Seals-Albatross Island, White Shark populations), economic (tourism-dive and fishing charters, marine scalefish fisheries), social (recreation, aesthetic values), scientific (Dangerous Reef-key research site for monitoring of White Shark populations, Australian Sea Lions), national (national importance for breeding colonies of Australian Sea Lions, Register of the National Estate-Sir Joseph Banks Group), practicality (insulation, compatibility-adjacent to Sir Joseph Banks Conservation Park). Lincoln National Park-Thorny Passage − Peake Bay - Point Bolingbroke Prime IUCN Conservation Values: rare and endangered species/habitats, aesthetics, biodiversity, cultural values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monument – Cape Catastrophe, Memory Cove, Cape Donington), ecological (significant breeding and haul out sites for New Zealand Fur SealsLiguanea Island, Low Rocks, Albatross Island, Williams Island, Curta Rocks, Cape Rock, breeding and haul out sites for Australian Sea Lions-Liguanea Island, Curta Rocks, Cape Rock, Williams, Smith, Little, Hopkins, Lewis, Thistle, Albatross Islands, White Shark populations, breeding sites for Short-tailed Shearwater, Flesh-footed Shearwater, Little White-faced Storm Petrel, White-bellied Sea Eagle, Ospreys), economic (tourism-dive and fishing charters, significant area for Greenlip Abalone, Blacklip Abalone, Southern Rock Lobster), social (recreation, aesthetic values, whaling stations-Thistle Island, Sleaford Bay, Memory Cove, historic shipwrecks`Investigator’), national (national importance of − Prime IUCN Conservation Values: cultural values, biodiversity, social values (IUCN Category III). IUCN Identification Criteria: naturalness, (not subjected to human-induced change), ecological (ecological integrity, diversity of marine habitats, extensive seagrass meadows, reefs, nursery, feeding areas for economic species-marine scalefish), economic (marine scalefish fisheries, tourism), social (Point Bolingbroke-aboriginal fish trap complex and campsites, recreation), practicality (accessibility). Salt Creek-Tumby Bay-Tumby Island − Prime IUCN Conservation Values: education, biodiversity, rare and endangered species/habitats, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats), ecological (diversity of coastal and marine habitats, mangroves, samphires, Page 102 SPENCER GULF REGION – JUSSIEU BIOUNIT seagrass meadows, estuarine function, nursery, feeding areas for economic species-Western King Prawn, marine scalefish, threatened waterbird species - Eastern Curlew, Fairy Tern, seabirds - Black Swan, Australian Pelican, White-faced Heron, and Cormorants), economic (marine scalefish fisheries, tourism), social (aboriginal fish trap complex, recreation, education, mangrove board walk-Tumby Bay), national (Wetland of National ImportanceTumby Bay, Register of the National EstateTumby Island Conservation Park), practicality (insulation, accessibility, compatibility-adjacent to Tumby Island Conservation Park). Proper Bay-Porter Bay-Spalding Cove − Prime IUCN Conservation Values: biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: biogeographic (representative marine habitats), ecological (diversity of marine habitats, extensive seagrass meadows, estuarine function, nursery, feeding areas for economic speciesmarine scalefish, threatened waterbird species – Cape Barren Goose, Musk Duck), economic (marine scalefish fisheries, tourism), social (aboriginal fish traps, recreation), national (potential for listing on the Register of the National Estate), practicality (accessibility, compatibility-adjacent to Lincoln National Park). Tod Estuary (Louth Bay) Prime IUCN Conservation Values: biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: biogeographic (representative marine & estuarine habitats, one of the few true estuaries on the Eyre Peninsula), ecological (diversity of coastal and marine habitats, mangroves, samphires, seagrass meadows, estuarine function, nursery, feeding areas for economic species-marine scalefish, threatened waterbird species – Cape Barren Goose, Musk Duck), economic (marine scalefish fisheries, tourism), social (aboriginal fish traps, recreation), national (Wetland of National Importance-Tod River wetland system, potential for listing on the Register of the National Estate), practicality (accessibility, compatibility-adjacent to Tod River wetland system). Page 103 SPENCER GULF REGION – DUTTON BIOUNIT XI MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE DUTTON BIOUNIT This biounit extends from Salt Creek (near Tumby Bay) to Cape Driver (Arno Bay) on the western side of central Spencer Gulf and covers an area of 255,443 ha. The biounit faces southeasterly into Spencer Gulf. subdominants. Rock surface dominated by the encrusting and articulated coralline algae (eg. Amphiroa) and the prostrate brown alga, Lobophora variegata. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This region forms the central western section of Spencer Gulf and has an overall easterly orientation. Consequently, it is a zone of low wave energy with prevailing offshore winds. 2 GEOLOGY AND GEOMORPHOLOGY 18 • Seagrass − On sandy substrates, subtidal communities dominated by Amphibolis antarctica in shallow waters (6m) and Posidonia sinuosa in deeper waters. Extensive meadows occur south of Port Neill, and north of Lipson Island. COASTAL Lipson Cove shingle ridge is backed by minor dune transgression and fronted by an 80m wide beach. A barrier-cum-tombolo backed by a single shingle ridge has developed in the lee of Lipson island. − Port Neill consists of a narrow transgressive barrier backed by tidal flats. MARINE CONSERVATION VALUES 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly low rocky shores and sandy beaches. − Of the total inshore subtidal habitats mapped in this biounit (26,093 ha), seagrass meadows comprise 25,706 ha (98.5%), reefs comprise 197 ha (0.8%), and sandy bottoms comprise 190 ha (0.7%). Coastal and Offshore Islands (or Reefs) 1 SIGNIFICANT BIOLOGICAL/PHYSICAL FEATURES 1.1 − Major Benthic Communities • Macroalgal − 18 On moderately exposed rocky coasts (ie. Port Neill), sutidal communities dominated by Ecklonia radiata and mixed fucoids, comprising Sargassum linearfolium, S.paradoxum, S.spinuligerum, S.lacerifolium) with species of Cystophora (C. expansa, C.monoliformis, and C.brownii) as Lipson Island (Lipson Cove). 1.2 − Biological Lipson Island Conservation Park is a breeding site for protected seabirds, including Little Penguins, Black Faced Cormorants, Crested Terns and the `vulnerable' Fairy Tern (Copley 1996). The park is on the Register of the National Estate. Silver Gull breeding sites are also located on Tumby Island, Lipson Cove, and Lipson Island. Physical Not known. From Eyre Peninsula Coast Protection District Study Report. Page 104 SPENCER GULF REGION – DUTTON BIOUNIT 2 OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries which operate in this region include: Western King Prawn. There is also a marine scalefish fishery in this region which targets, among other species, Snapper, King George Whiting and Shark. No Southern Rock Lobster and very little abalone is commercially harvested in this region. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Abalone Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Tumby Bay: 4 restricted marine scalefish, 9 unrestricted marine scalefish. − Port Neill: 1 restricted marine scalefish, 3 unrestricted marine scalefish 2.2 No aquaculture development or activities current occur in this region. However, the Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: Tumby Bay Policy Area − Offshore Tumby Management Zone (waters offshore from Massena Bay) – zoned for aquaculture development. Licenses will be considered for a maximum of 60ha of finfish culture within this zone. − Tumby Management Zone (inshore coastal waters, within 1km of the coast, from Salt Creek to south of Cape Driver, excluding waters adjacent to Lipson Island Conservation Park and waters surrounding Port Neill) – zoned for future aquaculture development. Licenses will be considered for a maximum of 30ha of aquaculture development within this zone. − Port Neill Zone (all remaining waters, out to 3nm from coast, from Salt Creek to south of Cape Driver) – zoned to preserve existing values and uses. Licenses will not be considered for aquaculture development within this zone. Very little abalone is presently commercially harvested within this biounit. (ie. MapCode 20A, 20C, Cape Donnington to Port Neill region). No Greenlip Abalone was harvested in 1994/95. No Blacklip Abalone was harvested within this region during 1994/95 and 1995/96. Marine Scalefish Fisheries During 1995/96 and 1996/97, 25 and 30 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish and Northern Zone Rock Lobster licence categories) caught commercial marine scalefish species from the Dutton Biounit (ie. Fishing Zone 29), respectively. License holders expended approximately 1249 and 1262 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 29) represented 35,347 kg in 1995/96 and 52,710 kg in 1996/97(or 0.34% and 0.52% of the total catch for the marine scalefish fishery in South Australian waters). Aquaculture 2.3 Recreation and Tourism Fishing − Tumby Bay: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Garfish, Blue Swimming Crab, Tommy Rough and Southern Calamari. Tumby Bay is unique in the fishing world as the `Gateway to the Group', the Sir Joseph Banks Group of islands, which provide some of the best cruising and fishing in South Australia. First Creek is used frequently by boat fishermen as an outlet channel to gain access to the sea. Page 105 SPENCER GULF REGION – DUTTON BIOUNIT − Port Neill: boat, jetty, and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally and Southern Calamari. Tourism − Urban Centres − 2.6 Features SCUBA diving: Tumby Bay jetty, Lipson Cove and Lipson Island (particularly the northern side of the island) are all recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Lipson Cove is also suitable for snorkelling. Aboriginal Point Bolingbroke: Aboriginal fish traps and campsites (Martin 1988). − Salt Creek: Aboriginal fishtrap complex. European Not known. Tumby Bay: camping, fishing. − − Port Neill: popular and safe swimming beach, boating, holiday flats and shacks. 3 2.5 Research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Adjacent Land Use National and Conservation Parks − Lipson Island Conservation Park (1 ha). Agriculture/Industry − CURRENT CONSERVATION STATUS OF THE DUTTON BIOUNIT Scientific Research and Education Tumby Bay mangrove boardwalk and interpretation centre, is a key destination for tourists and students (from local and regional centres) interested in estuaries and the mangrove environment. The boardwalk and interpretation centre is located on First Creek (in the township of Tumby Bay), and was designed and established by local community and LandCare groups within the Tumby Bay region. − Significant Cultural and Historical − − 2.4 Tumby Bay (population 996). A boat harbour channel was dredged in 1978 to connect the township with First Creek, and serves as an area to moor or launch boats. Apart from land reserved as Conservation Park, most adjacent coastal land in this biounit is developed for agricultural purposes. − Marine Reserves None − Marine Parks None − 4 Netting Closures Port Neill (all waters west of a line from Cape Burr to a point on the mainland 1.5km north of the jetty). AREAS OF HIGH CONSERVATION VALUE IN THE DUTTON BIOUNIT Lipson Cove-Lipson Island − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats), ecological (diversity of marine habitats, breeding sites for seabirds-Little Penguins, Black Faced Cormorants, Silver Gulls, Crested Terns and the `vulnerable' Fairy Tern), economic (marine scalefish fisheries, tourism), social (recreation), national (Register of the National EstateLipson Island Conservation Park), practicality (insulation, compatibility-adjacent to Lipson Island Conservation Park). Page 106 SPENCER GULF REGION – FRANKLIN BIOUNIT XII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE FRANKLIN BIOUNIT This biounit extends from Cape Driver (Arno Bay) on the western side of central Spencer Gulf to Victoria Point, near the mouth of Franklin Harbour and covers an area of 198,588 ha. The biounit faces southeast into Spencer Gulf. Port Gibbon is dominated by a beach fronted stranded cliff. At Dutton River mouth, fluvial deposits have been reworked into a 200m wide foredune ridge plain. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY The coast experiences a slightly higher wave energy with some sections also exposed to higher velocity onshore (west to south westerly) winds. 2 GEOLOGY AND GEOMORPHOLOGY19 COASTAL In summary, the coastal morphology is dominated by low energy reflective beaches, backed by single stable to semi-stable foredunes and fronted by relatively narrow sandflats. In addition, rocky coast with low cliffs occur along most of the coast, often with beaches forming in small crenulations and/or fronting the low cliffs. Some of the cliffs are unprotected by beaches and are eroding. In places they have irregular rocky strandflats up to 100m wide. This area represents the largest single Holocene sediment sink on the Spencer Gulf coast. Longitudinal Pleistocene dunes fronted by barrier samphire flats intersect the coast south of Mokami. The more protected Arno Bay contains extensive backbarrier tidal flat deposits fronted by a beach to foredune ridge transition. The bay entrance contains ebb and flood tide delta deposits and a moderately dynamic entrance. Mills Beach, south of Point Gibbon is a higher energy system, with a beach ridge to barrier sequence underlain by shingle ridges and backed by scarped conglomerates. The barrier is capped by the most extensive dune transgression encountered in the western Gulf, with some dunes reaching up to 500m inland. Drifting over the last 40 years has resulted in some dunes moving up to 100m. 19 Franklin Harbour (80 km2) is a typical southern Australian enclosed bay (after Roy 1984). It is a barrier estuary type, the beach embayment being blocked by a barrier to the north to Germein Point and a barrier to the west from Lucky Bay. Both barrier consist of foredune ridges with extensive recurved spits extending well into the bay. At the bay entrance, extensive ebb tide delta deposits (7 km2) occur with even more extensive deposits within the bay itself. These delta deposits have filled 50% of the bay and are composed of both subaerial and subaqueous marine deposits, cut by three major tidal channels. Intertidal sandy-mud flats partially covered by mangroves surround the bay shore, creeks and the lee of the barrier and recurved spits of the harbour. In places the mangroves are continuing to prograde into the bay. The major contributions to bay sedimentation are the wave and tide induced ebb and flood tide delta deposits, the wave and wind formed barriers, and the intertidal mud and mangrove flat deposits. Only one minor creek, Poodra Creek, drains into the bay. There is a continuous foredune ridge barrier extending from Point Germein to The Knob. A steep reflective beach indicates that waves rarely exceed 0.5m. South of Franklin Harbour, embayments of varying size have acted as the main Holocene sediment sinks, leading to the development of barrier/back barrier deposits. From Eyre Peninsula Coast Protection District Study Report. Page 107 SPENCER GULF REGION – FRANKLIN BIOUNIT 3 BIOLOGY Major Inshore Habitats − − − estuarine and mangrove area with associated samphire flats and mudflats (Franklin Harbor); sandy beaches; rocky shores; seagrasses. Major intertidal habitats in the region include bays (ie. mangroves, saltmarshes, intertidal mudflats), sandy beaches and rocky shores. Of the total inshore subtidal habitats mapped in this biounit (142,066 ha), sandy bottoms comprise 87,258 ha (61.4%), reefs comprise 39 361 ha (27.7%), and seagrass meadows comprise 15,447 ha (10.9%). Major Benthic Communities • − • − Macroalgal On moderately exposed rocky shores (eg. Cape Driver, Arno Bay), subtidal macroalgal communities are dominated by Ecklonia radiata and mixed fucoids (eg. Sargassum linearifolium, S.spinuligerum, S.lacerifolium and S.distichum), with species of Cystophora (C.expansa, C.moniliformis, C.brownii) as sub-dominants. Rock surfaces are commonly dominated by the prostrate understorey brown algae, Lobophora variegata and encrusting and articulated coralline algae (eg. Amphiroa sp.). Seagrass Sandy sediments in this region are colonised by Posidonia sinuosa and Amphibolis antarctica in shallower waters. Extensive meadows in Franklin Harbor and off Arno Bay, south to Dutton Bay. − Coastal and Offshore Islands (or Reefs) None. − Rivers/Estuaries Franklin Harbour estuary. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL/PHYSICAL FEATURES Biological Coastal and Marine Wetlands of National Importance − Franklin Harbour (and the Franklin Harbour Conservation Park) has been recognised as a wetland of national importance (see ANCA 1996). The harbour is a shallow almost totally landlocked embayment with two entrance points to the harbour and a long narrow sandy peninsula, protecting the mouth of Franklin Harbour, with four inner bay islands. The bay provides habitat for migratory waders, and the islands provide a safe roosting and feeding site for seabirds. Threatened species include the White-bellied Sea Eagle, Haliaeetus leucogaster (Sv) and the Musk Duck, Biziura lobata (Sv). A total of 14 waterbird species has been recorded; 4 listed under treaties. Breeding colonies of Pied Cormorants, Phalacrocorax varius and Black-faced Cormorants, P.fuscescens occur with the bay, and also, a breeding pair of the White-bellied Sea Eagle. Caspian Terns breed on Entrance Island (Copley 1996). White-faced Herons and large flocks of Grey Teal feed in the tidal shallows. The islands and the sheltered waters on the harbour side of the Peninsula have a low woodland of mangroves (Avicennia marina) and a tidal saltmarsh. Dense beds of seagrass meadows (ie. Posidonia sinuosa) are widespread throughout the bay and are important sites for spawning, breeding or shelter for numerous fish species. The brown alga, Scaberia agardhii, dominates rocky areas within the bay. The estuary supports substantial and diverse areas of wetland that would provide habitat for estuarine and offshore fish stocks. A total of 13 species of fish have been recorded, including juvenile King George Whiting, Garfish, Tommy Rough, Snapper, Snook and Squid. The size of the estuary and the extent and diversity of its associated wetlands suggest that its contribution to the ecology of Spencer Gulf would be significant (Bucher & Saenger 1989). The park is on the Register of the National Estate. The Spencer Gulf region has been identified as an area of international importance for shorebirds by Watkins (1993). Page 108 SPENCER GULF REGION – FRANKLIN BIOUNIT regions, due to the long history of trawling activities in the gulf. The species is widely distributed throughout the tropical IndoPacific, and occurs along the southern Australian coast, most commonly in bays and gulfs to a depth of about 25m. Other Areas of Recognised Conservation Significance Arno Bay (Salt Creek). The mangrove and tidal saltmarsh communities of Salt Creek represent a significant and poorly represented coastal landform in the eastern region of lower Spencer Gulf. The tidal communities which extend approximately 400 ha, are of considerable ecological and economic significance providing important nursery, feeding and breeding areas for many commercially and recreationally important species of fish and crustacea, including King George Whiting, Yellowfin Whiting, Southern Sea Garfish, and the Blue Swimming Crab. The geomorphological significance of the extensive tidal flat and dune structures have been recognised with the nomination of this area as a `geological monument’ (see below), while the presence of an Aboriginal fishtrap complex provides cultural significance to the region. The conservation significance of this ecosystem was recognised with the purchase of this land (with contains the majority of the creek and entrance) by the Coast Management Branch and Coast Protection Board, which purchased the land to ensure the environmental integrity of the area was protected against inappropriate development. While the mangroves at present are generally healthy along the tidal creek system, the lower section of the creek appears to be under stress from the effects of recreational activities (Burton 1984). − − About half way along the Point Germein Peninsula are mud flats covered by the bluegreen alga, Oscillatoria sp. forming stromatolite-like mounds of sediment. Although not as spectacular as the stromatolites of Shark Bay, Western Australia, they are nevertheless significant (Butler et al. 1975). Old colonies of the coral, Plesiastrea versipora is known to occur on reefs in some areas of the central and northern Spencer Gulf region. On a biological survey of Spencer Gulf in 1995 by the South Australian Research and Development Institute (SARDI), large coral colonies up to 1.5 m high were located in the Shoalwater Point to Arno Bay region. Colonies of P.versipora, typically have polyps usually coloured green to brown. While colonies may be small and encrusting, massive old colonies up to 3m in diameter are occasionally found in deeper water or dredged up by trawlers. In Spencer Gulf, there are historical records of large colonies dredged up by trawlers, and it is probable that old massive colonies are rare and isolated in the gulf 1.2 Physical Geological Monuments − 2 Arno Bay: coastal landforms. OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries which operate in this region include: Western King Prawn. There is also an extensive marine scalefish fishery in this region which targets, among other species, Snapper, King George Whiting and Shark. Trawling for Western King Prawn occurs further away from the coast. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Abalone Limited abalone is presently commercially harvested within this biounit. (ie. MapCode 21J, Arno Bay to Cowell region), but due to confidentiality constraints these figures are not available. Marine Scalefish Fisheries This biounit encompasses 2 fishing zones: Fishing Zone 19 and Fishing Zone 20 (Franklin Harbour). During 1995/96 and 1996/97, 10 and 7 commercial licence holders (made up of Marine Scalefish, and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the waters of Franklin Harbour (ie. Fishing Zone 20), respectively. License holders expended approximately 447 and 322 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 20) represented 52,098 kg in 1995/96 and 30,230 kg in 1996/97(or 0.50% and Page 109 SPENCER GULF REGION – FRANKLIN BIOUNIT 0.30% of the total catch for the marine scalefish fishery in South Australian waters). In the waters outside Franklin Harbour (ie. Fishing Zone 19), 13 and 10 commercial licence holders fished during 1995/96 and 1996/97. License holders expended approximately 608 and 468 boat days effort fishing these waters during 1995/96 and 1996/97, with a total catch of 17,709 kg and 15,119 kg, respectively (or 0.17% and 0.15% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − − − 2.2 Franklin Policy Area − Cleve Management Zone (coastal waters, out to 3nm from the coast, from south of Cape Driver to south of Point Gibbon, excluding the waters of Arno Bay) – zoned for potential aquaculture development. Licenses will be considered for a maximum of 60ha of aquaculture development within this zone, following the successful completion of an R&D program. − Port Gibbon Management Zone (coastal waters, out to 3nm from the coast, from Poverty Bay to Germein Point, excluding 1km zone of coastal waters from Point Gibbon to Germein Point) – zoned for potential aquaculture development. Licenses will be considered for a maximum of 40ha of aquaculture development within this zone, excluding 1km seaward of . − Shoalwater Point Management Zone (coastal waters, out to 3nm from the coast, from Germein Point to northern boundary of Munyaroo Conservation Park) – zoned for potential aquaculture development. Licenses will be considered for a maximum of 40ha of aquaculture development within this zone. Arno Bay: 2 restricted marine scalefish Mt Dutton Bay: 1 restricted marine scalefish Cowell: 1 restricted marine scalefish, 12 unrestricted marine scalefish. Aquaculture Franklin Harbour is a major site for intertidal oyster culture in South Australia. There are currently 114.5 ha of approved commercial oyster leases and one R&D finfish lease within the bay. The bay has been divided into 2 aquaculture management zones: the North Eastern Basin (2 400 ha) and the South Western Basin (approximately 2,200 ha). The majority of approved leases are in the South Western Basin, which has a virtual complete cover of seagrass. The Franklin Harbour Aquaculture Management Plan (1995) recommends the following aquaculture development within the harbour: 2.3 Fishing − Cowell, Lucky Bay, Franklin Harbor: boat, jetty, and beach fishing. Major species: King George Whiting, Yellowfin Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally, Toothbrush Leatherjacket and Southern Calamari. − Arno Bay: boat, jetty, and shore fishing. Major species: King George Whiting, Yellowfin Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally and Southern Calamari. − There is an artificial reef near Port Neill (sunken vessel). Franklin Harbour Zone − Licenses will be considered for a maximum of 119.5 ha of oyster culture within this zone. − Applications for relocation of leases within a subzone or from the South Western Basin to the North Eastern Basin will be considered. No applications for relocation to the South Western Basin will be considered. − Licenses will be considered for a maximum of 5ha of culture of non-filter feeding species, upon successful completion of an R&D program. No aquaculture development or activities currently occur in this region outside Franklin Harbour. However, the Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: Recreation and Tourism Page 110 SPENCER GULF REGION – FRANKLIN BIOUNIT Tourism − − 2.4 − − 2.5 2.6 Features SCUBA diving: Redbanks (north of Arno Bay) is a recognised reef dive and listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Redbanks consists of a reef running from shore out to two reefs running parallel to the coast. The dive (down to 9m), suitable in most weather conditions, consists of swim throughs, bommies and undercuts with many varieties of fish life inhabiting the reef. Arno Bay: boating. Scientific Research and Education Arno Bay (Salt Creek) is the site of a proposed coastal wetland interpretative trail, to be established with funding assistance from CoastCare and local council. The mangrove forests and extensive coastal saltmarshes adjacent to Salt Creek, and also the nearshore reefs of Arno Bay, are presently the site of significant recreational activity, including canoeing, swimming and fishing. The lower sections of the creek appear to be under stress from the effects of recreational activity (Burton 1984). Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Adjacent Land Use Aboriginal − Mills Beach by Point Gibbon: Aboriginal fishtrap. − Franklin Harbor & Searle Hill: only 2 outstanding examples of stone barrier fishtraps in the Mid Eyre Peninsula region. − 3 Franklin Harbour Conservation Park (1,334 ha). Agriculture/Industry − Most adjacent land in this biounit is used for agriculture. Urban Centres − − Cowell (population 692). Port Neill (population 510). European Not known. CURRENT CONSERVATION STATUS OF THE FRANKLIN BIOUNIT − Marine Reserves None − Marine Parks None − Netting Closures Arno Bay (all waters west of a line from the land 200 m north of the end of the jetty due south to a point known as South Point on Cape Driver). − Cowell, Franklin Harbour (all the waters of Franklin Harbour situated north west of a line from Victoria Point to Germein Point). 4 AREAS OF HIGH CONSERVATION VALUE IN THE FRANKLIN BIOUNIT National and Conservation Parks − Significant Cultural and Historical Arno Bay − Prime IUCN Conservation Values: education, social values, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (geological monument-Arno Bay, representative marine habitats), ecological (range of marine habitats, mangroves, saltmarshes, estuarine function, significant nursery, feeding area for economic speciesWestern King Prawn, marine scalefish), economic (marine scalefish fisheries, tourism), social (recreation-kayaking, education), practicality (insulation, accessibility). Page 111 SPENCER GULF REGION – FRANKLIN BIOUNIT Mills Beach-Franklin Harbor − Prime IUCN Conservation Values: biodiversity, social values, rare and endangered species/habitats, cultural values, (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change, adjacent to intact terrestrial catchment), biogeographic (representative marine habitats), ecological (diversity of marine habitats, mangroves, seagrasses, nursery, feeding areas for economic species – Western King Prawn, marine scalefish, stromatolites, threatened seabirds - Whitebellied Sea Eagle, breeding colonies of Pied Cormorants, Black-faced Cormorants, Caspian Terns, ecological integrity), economic (marine scalefish fisheries, tourism), social (aboriginal fish traps, recreation), national (Register of the National Estate-Franklin Harbour), practicality (insulation, accessibility, compatibilityadjacent to Franklin Harbour Conservation Park). Page 112 SPENCER GULF REGION – YONGA BIOUNIT XIII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE YONGA BIOUNIT This biounit extends from Victoria Point (near the mouth of Franklin Harbor) to Point Lowly on the western side of Spencer Gulf to, Ward Point and Point Riley on the eastern side of the gulf, and covers an area of 423,556 ha. The biounit occupies the central northern waters of Spencer Gulf. MARINE BIOGEOGRAPHY Lucky Bay has a foredune ridge backed by a saline flat that becomes flooded during storm surges. 1 In the vicinity of Lowly Point (and also, in the northern, more estuarine part of the Gulf), strong tidal currents have scoured the channel floor and produced 200-500m wide belts of megaripples orientated parallel to the channel margins. OCEANOGRAPHY Predominantly low wave energy. Slightly higher wave energy occurs south of Shoalwater Point, where the coast faces the strong south to southwesterly winds and waves as well as occasional ocean swell. 3 The northern reaches of Spencer Gulf is an area of low to very low wave energy. BIOLOGY Major Inshore Habitats The extreme tidal range at Port Pirie is 3.1m with a maximum range over a single tidal cycle of 2.9m. − Major intertidal habitats in the region include mangroves, low rocky shores, and some sandy beaches. 2 − Of the total inshore subtidal habitats mapped in this biounit (420,365 ha), seagrass meadows comprise 248,596 ha (59.1%), sandy bottoms comprise 161,715 ha (38.5%), and reefs comprise 10,054 ha (2.4%). GEOLOGY AND GEOMORPHOLOGY20 COASTAL This section of coast has a uniform orientation and exposure to the predominantly low wave energy gulf, coupled with a low gradient Pleistocene calcareous surface mantled by east-west trending stable longitudinal dunes. Coastal geomorphology is dominated by beach ridge plains averaging 730 m in width, fronted by wide inter- to subtidal sand flats. The beaches are capped with low vegetated dunes and backed by wide, low inter to supratidal flats covered by samphire vegetation. Mangroves grow in the tidal creeks and occasionally on the open coast. South of Shoalwater Point, the coast faces strong south to southwesterly winds and waves as well as occasional ocean swell, producing a higher energy shoreline with foredune ridges. The shoreline consists of a wide intertidal sandflat which grades into seagrass meadows. Steeper gradients occur as the shoreline progrades seaward into deeper water. 20 Major Benthic Communities • Macroalgal − On rocky shores (ie. Shoalwater Point), subtidal communities are commonly dominated by a mixed red algal assemblage, dominated by Osmundaria and to a lesser extent, Cladurus elatus, Dictymenia sonderi, Botrycladia and also, the brown algae, Caulocystis and Sargassum spinuligerum. At Point Lowly, subtidal community dominated by Hammer Oysters, Scaberia agardhii, mixed-Cystophora species (ie. C.botyroides, C.expansa, C.polycystidea), Lobophora, Caulocystis and Sargassum linearifolium. From Eyre Peninsula Coast Protection District Study Report. Page 113 SPENCER GULF REGION – YONGA BIOUNIT • − Extensive Mangrove and Tidal Wetlands Seagrass Extensive areas of seagrass occur in this region, and comprise some of largest seagrass meadows recorded in South Australia (representing 29.2% of the total area of seagrass recorded in the State). Sandy sediments in this region (eg Middle Bank) are commonly dominated by Posidonia sinuosa and P.angustifolia in deeper waters and Amphibolis antarctica in shallower waters. − Coastal and Offshore Islands (or Reefs) Weerona Island (Port Pirie). − − − Rivers/Estuaries First - Seventh Creek (Port Pirie). Port Davis Creek (south of Port Pirie). Fisherman Creek (Port Broughton). − This biounit contains some of the largest areas of temperate tidal wetlands and mangroves in South Australia (and Australia). Spencer Gulf (along with Gulf St Vincent) contains some of the most extensive areas of mangrove forests and tidal wetlands in South Australia (and the largest areas of temperate mangroves in Australia) (Edyvane 1996). Associated with the mangrove habitats are the biologically rich mud flats, coastal saltmarshes and seagrasses. Together, these communities provide key habitats for waterfowl and waders, and important feeding, breeding and nursery areas for economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Mangrove and saltmarsh communities along the South Australian coast total approximately 82,000 ha, with the largest communities occurring in Spencer Gulf (46,000 ha) and Gulf St Vincent (20,000 ha). Other substantial communities occur in lower Spencer Gulf (6,000ha), on the west coast of Eyre Peninsula (9 000 ha) and on Kangaroo Island (7 000 ha) (DELM 1993). In Spencer Gulf, mangrove forests occur north of Point Lowly, from Port Pirie to Port Broughton, in Franklin Harbour, and to a lesser degree near Tumby Bay. − The size of the Northern Spencer Gulf estuary and its extent and diversity of its associated wetlands suggest that its contribution to the ecology of Spencer Gulf would be significant (Bucher & Saenger 1989). This region contains extensive areas of ecologically significant wetland habitat comprising mangroves, seagrass and tidal saltmarsh communities, together comprising one of the largest coastal wetland ecosystems in South Australia: − Port Davis Creek - greater than 75% of the catchment has been cleared of natural vegetation. 12.07 km2 of intertidal sand/mud flats; 16.59 km2 of mangroves; 13.41 km2 of salt flats/salt marsh. − Third Creek (Port Pirie) - greater than 75% of the catchment has been cleared of natural vegetation. 0.89 km2 of intertidal sand/mud flats; 1.93 km2 of mangroves; 9.80 km2 of salt flats/salt marsh. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Seagrass Meadows − The seagrass meadows of this biounit represent the largest areas in Spencer Gulf and also, South Australia. These extensive seagrass meadows flourish in the shallow waters, generally in waters less than 15m, and provide the basis for the significant productivity of the region in terms of fisheries and prawn production. . Seagrasses cover a total area of approximately 5,512 km2 in Spencer Gulf, of which 4138 km2 is located in northern Spencer Gulf (ie. north of Point Riley). Together, the seagrasses of Spencer Gulf represent 57% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the central northern reaches of the gulf (ie. Yonga Biounit, 248,596 ha), in the Tiparra Reef region (ie. Tiparra Biounit, 83,912 ha) and the Port Lincoln region (ie. Jussieu Biounit, 56,956 ha). Page 114 SPENCER GULF REGION – YONGA BIOUNIT − − − − Second Creek (Port Pirie) - greater than 75% of the catchment has been cleared of natural vegetation. A sewage treatment works is located on the coastal flats associated with the estuary and could be a source of pollutants and nutrients. 2.30 km2 of intertidal sand/mud flats; 6.03 km2 of mangroves; 11.76 km2 of salt flats/salt marsh. First Creek (Port Pirie) - greater than 75% of the catchment has been cleared of natural vegetation. 8.04 km2 of intertidal sand/mud flats; 11.59 km2 of mangroves; 9.93 km2 of salt flats/salt marsh. Whyalla-Cowleds Landing Aquatic Reserve − Munyaroo Conservation Park − Fisherman Creek (Port Broughton) - greater than 75% of the catchment has been cleared of natural vegetation. 6.75 km2 of intertidal sand/mud flats; 8.42 km2 of mangroves; 13.25 km2 of salt flats/salt marsh. The size of the wetland habitat in the WhyallaPirie Region and the extent and diversity of its associated wetlands suggest that its contribution to the ecology and fisheries productivity of Spencer Gulf would be significant (Bucher & Saenger 1989). − The mangrove and seagrass areas of Northern Spencer Gulf constitute important nursery areas for several commercial fish and crustacean species caught both locally and in the southern areas of Spencer Gulf. In terms of overall fisheries production, the northern reaches of Spencer Gulf (south of Point Lowly) supports the largest Western King Prawn (Penaeus latisulcatus) fishery in the Australia. Some 1,500 tonnes of prawns, valued at $20 million, are caught annually in the region, which represents approximately 75% of the State's total prawn harvest. Northern Spencer Gulf itself provides approximately 45% of the State's marine scalefish catch and more than 45% of the State's blue crab catch, although the bulk of the these catches occurs between Moonta and Ward Spit. Possible remnant South Australian population of Brush-tailed Bettongs. It has a beach and coastal dune system backed by samphire flats and claypans. The park is on the Register of the National Estate. Seabirds − Nursery Areas for Economic Species − Major habitat types include samphire flats which are flushed by extremely high spring tides; intertidal mangrove area; intertidal sand and mudflats; and subtidal seagrass meadows. Outstanding features include the extensive mangrove and seagrass areas which constitute important nursery areas for several commercial fish and crustacean species. Several protected seabirds breed in the region, including Pied Cormorants at Fisherman's Creek, Shag Island (Port Broughton), the mangrove creeks of Port Pirie, and Weerona Island (Port Pirie); Caspian Terns at Ward Spit (Point Germein); and the `vulnerable' Little Tern at Ward Spit. Recent studies indicate that the Little Tern may realistically be regarded as endangered within South Australia (Copley 1996). Giant Cuttlefish − The reefs off Point Lowly have recently been recognised as an area of major significance for the spawning aggregations of the Giant Cuttlefish (Sepia apama). The Giant Cuttlefish is the largest cuttlefish in the world and is only found in southern Australian waters. Females migrate to rocky areas to mate and lay a few (<100) large eggs for one season, and then die. The paucity of reef areas in the Northern Spencer Gulf region probably explain the unique aggregation of cuttlefish at Point Lowly, which represents one of the few rocky reef areas in the area. Cuttlefish require hard surfaces on which eggs can be laid and Cuttlefish probably migrate from wide area of the gulf to Point Lowly (Mark Norman, University of Melbourne, pers.comm.). Page 115 SPENCER GULF REGION – YONGA BIOUNIT Coral Colonies − 1.2 Old colonies of the coral, Plesiastrea versipora is known to occur on reefs in some areas of the central and northern Spencer Gulf region. On a recent biological survey of Spencer Gulf by the South Australian Research and Development Institute (SARDI), large coral colonies up to 1.5 m high were located in the Shoalwater Point to Arno Bay region. Colonies of P.versipora, typically have polyps usually coloured green to brown. While colonies may be small and encrusting, massive old colonies up to 3m in diameter are occasionally found in deeper water or dredged up by trawlers. In Spencer Gulf, there are historical records of large colonies dredged up by trawlers, and it is probable that old massive colonies are rare and isolated in the gulf regions, due to the long history of trawling activities in the gulf. The species is widely distributed throughout the tropical IndoPacific, and occurs along the southern Australian coast, most commonly in bays and gulfs to a depth of about 25m. Physical Geological Monuments − 2 2.1 "Glensea" (10 km north of Shoalwater Point): beach ridge plain. Its sequence is typical of central Spencer Gulf. There are 8 ridges of varying height and spacing extending 1,200m inland from HWM. The sequence provides a useful record of both Holocene sedimentation and sea-level change in the central Spencer Gulf region. It is well preserved and readily accessible by vehicle. OTHER VALUES Commercial Fisheries Western King Prawn is the major single species fisheries in this region. There is also an extensive marine scalefish fishery in this region which targets, among other species, Snapper, King George Whiting, Blue Swimmer Crab and Shark. The region is of major importance for the marine scalefish fishery, representing one of the most significant fishing grounds in South Australia. Trawling for Western King Prawn occurs further away from the coast. No abalone is commercially harvested within this region. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of the Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Marine Scalefish Fisheries This biounit encompasses one of the most significant fishing grounds in South Australia for the marine scalefish industry. The biounit encompasses 3 fishing zones: Fishing Zone 21, 22 and 23. During 1995/96 and 1996/97, 89 and 90 commercial licence holders (made up of Marine Scalefish, and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the southern waters of this biounit, south of Wood Point, including Fishery Bay (ie. Fishing Zone 22 and 23), respectively. License holders expended approximately 5644 and 5496 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zones 22 and 23) represented 604,011 kg in 1995/96 and 599,758 kg in 1996/97(or 5.81% and 5.92% of the total catch for the marine scalefish fishery in South Australian waters). In the northern waters of this biounit, from Wood Point north to Point Douglas, including Germein Bay and False Bay (ie. Fishing Zone 21), 57 and 61 commercial licence holders fished during 1995/96 and 1996/97. License holders expended approximately 4,624 and 4,791 boat days effort fishing these waters during 1995/96 and 1996/97, with a total catch of 660,899 kg and 869,656 kg, respectively (or 6.36% and 8.58% of the total catch for the marine scalefish fishery in South Australian waters). In total the marine scalefish catch for the Yonga Biounit during 1995/96 and 1996/97 represented approximately 12.16% and 14.49% of the total catch for the marine scalefish fishery in South Australian waters. Page 116 SPENCER GULF REGION – YONGA BIOUNIT Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Port Pirie: 2 Spencer Gulf Prawn, 6 restricted marine scalefish, 20 unrestricted marine scalefish, 1 experimental crab − Merninnie Landing: one unrestricted marine scalefish Whyalla: 5 restricted marine unrestricted marine scalefish 2.2 scalefish, 22 − Offshore Tickera Management Zone (offshore waters, from 1km to 3nm offshore, from Webling Point south to Point Riley) – zoned for potential aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development within this zone, excluding the culture of non-native oyster species. − Aquaculture Wallaroo Zone (remaining coastal waters, from just north of Fisherman Bay, south to Cape Elizabeth) – zoned to preserve existing values and uses. Licenses will not be considered for aquaculture development within this zone. Present aquaculture activities in this region include: the commercial culture of microalgae in extensive pond systems to the north of Whyalla and a R&D lease for the culture of finfish in sea cages in the BHP marina. 2.3 The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: − Lucky Bay: boat and beach fishing. Major species: King George Whiting, Yellowfin Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Sweep, Garfish, Blue Swimming Crab, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Point Lowly (Whyalla): boat, shore and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally and Southern Calamari. − There are artificial reefs located near Port Pirie (tyre modules) and Port Germein (sunken pipes). There are three artificial reefs near Whyalla (tyre modules). − Port Pirie: boat, jetty and shore fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally and Southern Calamari. − Port Broughton: boat, jetty and shore fishing. Major species: King George Whiting, Yellowfin Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally and Southern Calamari. Fishing Whyalla-Pirie Policy Area Murninnie Management Zone (waters 1km offshore from Murninnie Beach) – zoned for aquaculture development. Licenses will be considered for a maximum of 40ha of aquaculture within this zone. − Northern Spencer Gulf Zone (all remaining central northern gulf waters, from Murninnie Beach east to south of Wood Point, and Point Lowly to Ward Spit) – zoned to preserve existing values and uses. Licenses will not be considered for aquaculture development within this zone. Northern Yorke Peninsula Policy Area − Broughton Management Zone (3 areas, in the waters of Port Broughton) – zoned for R&D aquaculture development. Licenses will be considered for a maximum of 10ha of aquaculture development within this zone, following the successful completion of a R&D program. Recreation and Tourism Page 117 SPENCER GULF REGION – YONGA BIOUNIT Tourism − − − − − 2.4 − − 2.5 Urban Centres Lucky Bay: boating, holiday shacks. Point Lowly (Whyalla): boating. Whyalla, Point Lowly: boating. Port Pirie: boating. SCUBA diving: Point Lowly tyre reef is recognised dive spot and listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The tyre reef is close to shore and can be accessed via shore or via a boat dive, and attracts Snapper and Long Snouted Boarfish and other marine life. − − − 2.6 Features Significant Cultural and Historical − Not known. 3 CURRENT CONSERVATION STATUS OF THE YONGA BIOUNIT Scientific Research and Education Port Pirie and the associated mangrove creeks, tidal flats and nearshore seagrass meadows in the region (from First Creek to Port Davis Creek) have been the site of a major scientific studies into the effects of heavy metals on marine ecosystems (Ward et al. 1982, 1986, Edyvane & Boxall 1996), and more recently the effect of the `Era’ oil spill (Wardrop et al. 1993, Connolly & Jones 1996). Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); and regular research and monitoring of larval fish stocks. − Marine Reserves Whyalla-Cowleds Landing (3,230 ha) − Marine Parks None − Netting Closures Germein Bay (all waters of Germein Bay within a line from the mouth of Second Creek northwards to a point in the bay, then north westerly to Ward Spit light and east north east to Ward Point). − Port Broughton, Fisherman Bay (all waters of Fisherman Bay and Spencer Gulf east of a line from the northern point of Fisherman Bay to Shag Island then south to Webling Point) 4 AREAS OF HIGH CONSERVATION VALUE IN THE YONGA BIOUNIT Adjacent Land Use National and Conservation Parks − − Whyalla (population 26,900). Port Pirie (population 15,114). Both centres have permanent coastal moorings for recreational and commercial craft. Munyaroo Conservation Park (12,334 ha). Munyaroo Conservation Reserve (7,200 ha). Agriculture/Industry − Most adjacent land in this biounit is used for agriculture, except for the predominantly industrial cities of Whyalla and Port Pirie. − Algal culture industry situated near the saltpans of Whyalla. It uses the waste water from BHP steel factory. − Major port facilities occur at Whyalla and Port Pirie. Whyalla-Cowleds Landing − Prime IUCN Conservation Values: biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: biogeographic (representative marine habitats), ecological (range of marine habitats, mangrove forests, seagrass meadows, saltmarshes, nursery areas, feeding areas for economic speciesWestern King Prawn, marine scalefish), economic (marine scalefish fisheries, tourism), social (recreation), scientific (prawn, marine scalefish research and monitoring) national (Register of the National Estate-Munyaroo Conservation Park), practicality (insulation, accessibility, compatibility-adjacent to Munyaroo Conservation Park). Page 118 SPENCER GULF REGION – YONGA BIOUNIT Point Lowly Prime IUCN Conservation Values: biodiversity, social values (IUCN Category II). IUCN Identification Criteria: biogeographic (rare habitats-reef habitats within a seagrass dominated ecosystem), ecological (site of Giant Cuttlefish spawning aggregations, nursery, feeding and breeding areas for economic species-Western King Prawn, marine scalefish), economic (marine scalefish fisheries, tourism), social (recreation, diving), scientific (prawn, marine scalefish, research and monitoring), national (potential for Register of the National Estate). Germein Bay–Port Davis-Fisherman Bay − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, social values (IUCN Category IB). IUCN Identification Criteria: biogeographic (representative marine habitats, largest areas of coastal and marine wetlands in SA), ecological (range of marine habitats, large areas of mangroves, seagrasses, saltmarshes, numerous tidal estuaries – First, Second, Third, Fourth, Fifth, Sixth, Seventh Creek, Port Davis Creek, Fisherman Creek, key nursery, feeding areas for economic species – Western King Prawn, marine scalefish, breeding sites for `vulnerable’ Little Tern, Caspian Tern, Pied Cormorants), economic (marine scalefish fisheries, tourism), social (recreation), scientific (prawn, marine scalefish, mangrove, seagrass research and monitoring), national/international (international importance for shorebirds and Wetland of National Importance-upper Spencer Gulf wetlands, potential for RAMSAR listing), practicality (insulation, accessibility, compatibility-adjacent to Point Jarrold Sanctuary). Page 119 SPENCER GULF REGION – WINNINOWIE BIOUNIT XIV MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE WINNINOWIE BIOUNIT This biounit extends from Point Lowly (on the western side of Spencer Gulf) to Ward Point (on the eastern side of Spencer Gulf), to Port Augusta, and covers an area of 55,266 ha. The biounit occupies the far northern waters of Spencer Gulf. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY The far northern reaches of Spencer Gulf is an area of very low wave energy. The extreme tidal range at Port Augusta is 2.7 m with a mean spring tidal range of 2.0 m. High evaporation and limited freshwater inflow produce salinities in excess of 40%.. Evaporation results in the formation of ephemeral salt crusts on supratidal flats. Temporal and spatial gradients also exist in the water temperature which increases about 200C from Lowly Point to Port Augusta, and varies annually between 100C and 290C. 2 GEOLOGY AND GEOMORPHOLOGY21 The supratidal zone of the northern Gulf consists mainly of bare carbonate flats which are occasionally inundated by high spring or storm tides (Gostin et al. 1984). They cover about 138 km2 or 7% of the total area. A few stranded beach ridges and coastal dunes delineate the position of former shorelines. In water deeper than 10 m, over most of the Gulf, the seafloor is smooth and is underlain by a thin 0.5-2m sheet of mud and shell. Two algal and three animal assemblages in deeper water have been described. In the vicinity of Lowly Point and in the northern, more estuarine part of the Gulf, strong tidal currents have scoured the channel floor and produced 200-500m wide belts of megaripples orientated parallel to the channel margins. COASTAL Northern Spencer Gulf is the apex of an elongate marine protrusion into arid continental Australia, bordered by the industrial towns of Whyalla, Port Pirie and Port Augusta. Shallow depths (less than 25 m) and a semi-arid environment have resulted in a warm, saline body of water often referred to as an `inverse estuary'. Northern Spencer Gulf lies along a hinge zone between two major geological provinces of Late Precambrian age, the Adelaide Geosyncline to the east, and the Stuart Shelf to the west. 3 Major Inshore Habitats − Major intertidal habitats in the region include mangroves, saltmarshes, intertidal mudflats and sandy shores. − Of the total inshore subtidal habitats mapped in this biounit (54,211 ha), sandy bottoms comprise 37,727 ha (69.6%), and seagrass meadows comprise 16,484 ha (30.4%). No significant reef areas are recorded in this region. The coastal geomorphology is that of wide intertidal and supratidal areas, consisting of mudflats, mangroves and samphire flats. In the vicinity of Lowly Point and in the northern, more estuarine part of the Gulf, strong tidal currents have scoured the channel floor and produced 200-500m wide belts of megaripples orientated parallel to the channel margins. 21 BIOLOGY Major Benthic Communities • − Macroalgal Limited rocky substrate is recorded in this region. From Eyre Coast Protection District Study Report. Page 120 SPENCER GULF REGION – WINNINOWIE BIOUNIT • − Seagrass The shallow sublittoral zone of northern Spencer Gulf is dominated by stands of Posidonia australis and P.sinuosa with subordinate growth of Heterozostera tasmanica, Amphibolis antarctica and Halophila ovalis (Johnson 1982, Shepherd 1983, Gostin et al. 1984). The seagrass stands occupy broad shallow platforms, particularly along the eastern margin of the gulf, as well as on and around discrete offshore banks. The distribution of seagrass species with depth varies considerably between locations. Although P.australis may grow within the intertidal zone to almost mean sea level, massive growth predominates from between spring low water level to about 4m depth. Thereafter, P.sinuosa dominates to between 8 and 10 m depth (Shepherd 1983). MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES 1.1 − Extensive mangrove and tidal wetlands. This biounit contains the largest areas of temperate tidal wetlands and mangroves in South Australia (and Australia). Spencer Gulf (along with Gulf St Vincent) contains some of the most extensive areas of mangrove forests and tidal wetlands in South Australia (and the largest areas of temperate mangroves in Australia) (Edyvane 1996). Associated with the mangrove habitats are the biologically rich mud flats, coastal saltmarshes and seagrasses. Together, these communities provide key habitats for waterfowl and waders, and important feeding, breeding and nursery areas for economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Mangrove and saltmarsh communities along the South Australian coast total approximately 82,000 ha, with the largest communities occurring in Spencer Gulf (46,000 ha) and Gulf St Vincent (20,000 ha). Other substantial communities occur in lower Spencer Gulf (6,000ha), on the west coast of Eyre Peninsula (9,000 ha) and on Kangaroo Island (7,000 ha) (DELM 1993). In Spencer Gulf, mangrove forests occur north of Point Lowly, from Port Pirie to Port Broughton, in Franklin Harbour, and to a lesser degree near Tumby Bay. − The marine and coastal wetlands of upper Spencer Gulf have been identified as a wetland of national importance (see ANCA 1996). The upper Spencer Gulf region is an inverse estuary containing shallow, saline waters, and characterised by intertidal mangrove forests, tidal sand and mudflats (with some areas of shingle and sandy beaches), dissected by a network of tidal channels and creeks (eg. Chinaman Creek, First-Seventh Creek, Port Davis Creek, Fisherman Creek). The seagrasses support a rich and diverse epibiota characterised by red algae (King 1981). Epibenthos and infauna found amongst seagrasses in northern Spencer Gulf include crustaceans, the large bivalves Pinna, Pecten, Ostrea and Katelysia and numerous other molluscs (Shepherd 1983). In the Point Lowly channel (at 20m), which experiences strong tidal currents, the subtidal community is animal-dominated, particularly by Pinna, bryozoans, and sponges. Rivers/Estuaries − (Far) Northern Spencer Gulf, an `inverse' estuary that supports extensive seagrass growths in waters less than 10m. − Mambray Creek. Biological Coastal and Marine Wetlands of National Importance On the southern flank of the Yatala Harbour channel several crescentic scours have been observed. These are approximately 20-30 m wide and have a depth of some 2m. They appear similar to the "blowouts" reported by Shepherd and Sprigg (1976) in the seagrass meadows of the adjacent Gulf St Vincent. − AND Page 121 SPENCER GULF REGION – WINNINOWIE BIOUNIT The region includes the far northern reaches of the gulf from Whyalla (on the eastern side of Eyre Peninsula) to Port Broughton (on the western side of Yorke Peninsula), and includes the mangrove and coastal saltmarsh communities of Whyalla, Blanche Harbour, Port Augusta, Redcliff Point, Yalata Harbour, Port Germein, Port Pirie south to Point Jarrold, Fisherman’s Bay and Port Broughton. Below sea level, the habitats are dominated by extensive seagrass meadows in shallow waters and silty habitats in deeper waters (Shepherd 1974, 1983). The region contains the largest undisturbed stand of mangroves remaining in South Australia (particularly at Redcliff and Chinaman Creek) and the region is considered to be one of the finest examples of a subtropical marine and coastal ecosystem in the southern hemisphere, containing the richest and most diversified coastal flora in South Australia (ANCA 1996). Large sand waves or `megaripples’ characterise the deeper, channel areas of the upper gulf (Shepherd 1983, Shepherd & Hails 1984). The area has also been identified as an area of international and national importance for shorebirds by Watkins (1993). Threatened species of waterbirds include the Orange-bellied Parrot, Neophema chrysogaster (Ne, Se), Hooded Plover, Thinornis rubricollis (Nv, Sv), White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Osprey, Pandion haliaetus (Sv), Little Egret, Egretta garzetta (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), Slender-billed Thornbill, Acanthiza iredalei rosinae (Sv), Eastern Reef Egret, Egretta sacra (Sr), Spotted Crake, Porzana tabuensis (Sr) and Australasian Shoveler, Anas rhynchotis (Sr) (ANCA 1996). A total of 67 species of waterbirds have been recorded for the region: 19 are listed under international treaties. A total of 20 species have been recorded in the region, including the only specimen of the Broadbill Swordfish, Xiphias gladius, known to be caught in South Australian waters. Other notable fauna recorded in the region include the Hawksbill Turtle, Eretmochelys imbricata, dolphins and occasional sightings of sea lions, and whales. Seagrass Meadows − In upper Spencer Gulf, Johnson (1982) recorded 48 "erect" species of Rhodophyta and Phaeophyta epiphytic on Posidonia sinuosa leaves. Shepherd (1983) recorded 4 species of Chlorohpyta, 18 species of Phaeophyta and 62 species of Rhodophyta in the same area. The extensive seagrass meadows in turn support a prolific skeletal biota as infauna and epiphytes. In addition, numerous bacteria, diatoms and other micro-organisms are known to form thin coatings over leaf blades (Kuo 1978). Nursery Areas for Economic Species − The mangrove and seagrass areas of upper Spencer Gulf constitute important nursery areas for several commercial fish and crustacean species caught both locally and in the southern areas of Spencer Gulf. The size of the estuary and its extent and diversity of its associated wetlands suggest that its contribution to the ecology of Spencer Gulf would be significant (Bucher & Saenger 1989). The principal commercial species in the region include the Southern Sea Garfish, Hyporhamphus melanochir, King George Whiting, Sillaginodes punctata, Snapper, Chrysophrys auratus, Western Sand Whiting, Sillago schomburgkii, Tommy Ruff, Arripis georgiana, Snook, Sphyraena novaehollandiae and Australian Salmon, Arripis truttacea. A total of 11 species of crustaceans have been recorded in the region; the most common include the the Western King Prawn, Penaeus latisulcaus, Blue Swimmer Crab, Portunus pelagicus and Mud Crabs, Helice haswellianus. In terms of overall fisheries production, the northern reaches of Spencer Gulf (south of Point Lowly) supports the largest Western King Prawn (Penaeus latisulcatus) fishery in the Australia. Some 1500 tonnes of prawns, valued at $20 million, are caught annually in the region, which represents approximately 75% of the State's total prawn harvest. Upper Spencer Gulf itself provides approximately 45% of the State's marine scalefish catch and more than 45% of the State's blue crab catch, although the bulk of the these catches occurs between Moonta and Ward Spit. Upper Spencer Gulf is an inverse estuary that supports extensive seagrass meadows in waters less than 10m. Growth of Posidonia species is particularly vigorous, with high leaf blade production and turnover rates (West & Larkum 1979). Shepherd (1983) estimates an annual leaf blade productivity in excess of 9 kg/m2 in shallow water. The seagrasses support a rich and diverse epibiota characterised by red algae (King 1981). Page 122 SPENCER GULF REGION – WINNINOWIE BIOUNIT Relict Tropical Element in Marine Biota − The benthic flora and fauna of the northern reaches of upper Spencer Gulf is characterised by a significant and very distinctive, relict tropical element (Shepherd 1983) and is recognised as a distinctive biogeographical region known as the `Northern Spencer Gulf Bioregion' (IMCRA 1997). Although most of the algal species recorded in Northern Spencer Gulf have intermediate warm to cool temperate affinities (occurring throughout the southern Australian region), some algal species, such as Sargassum decurrens and Hormophysa triquetra, are nowadays only distributed in tropical and subtropical regions. Notwithstanding, other algal species, such as Asparagopsis taxiformis and Platysiphonis mutabilis, appear to have distinct warm temperate affinities, occurring only westward of the South Australian Gulfs. In addition to these species, Beanland & Woelkerling (1982) recorded a further four algal species, with tropical affinities, on mangrove pneumatophores. − The presence of some coelenterates in upper Spencer Gulf is also of special interest. Echinogorgia sp. and Scytalium sp. appear to be endemic in upper Spencer Gulf (Grasshoff 1982). Virgularia mirabilis, a cosmopolitan species, is known in South Australia only from this region (Utinomi & Shepherd 1982) and Telest multiflora, a tropical species, is recorded in southern Australia only in mid and upper Spencer Gulf (Verseveldt 1982). In addition, the ascidian, Sucozoa pedunculata is known in southern Australian only from upper Spencer Gulf and Investigator Strait (Kott 1972, 1975). These last four species except for V.mirabilis, appear to have tropical affinities suggesting that isolated populations are confined to Gulf waters. In addition, a number of species in other phyla newly or not yet described are known only from upper Spencer Gulf. They include the bryozoan, Bugula sp., a flatworm, Ancoratheca australiaensis and an opisthobranch, Discodoris. Further, the ophiuroid, Amphiura trisacantha is apparently rare elsewhere (Baker & Devaney 1981). − The benthic environment and the fauna of upper Spencer Gulf differ markedly from those of upper Gulf St Vincent, a region with similar temperature and salinity extremes. The latter region is generally shallow with deeper, silty bottom dominated by a Pinnaholothurian assemblage whereas upper Spencer Gulf has deeper channels, stronger water currents and generally well sorted medium to coarse shelly sands. Nowhere in upper Spencer Gulf does Pinna bicolor support the rich epizoic fauna described for upper Gulf St Vincent. Of the 32 species considered to be occasional to common in upper Gulf St Vincent by Shepherd and Sprigg (1976), only one echinoderm Goniocidaris tubaria, two molluscs, Pinna bicolor and Malleus meridianus, and one ascidian, Polycarpa pedunculata occur in comparable abundance in upper Spencer Gulf; the remainder appear to be rare or absent. On the basis of present knowledge of the fauna of the Gulfs, Northern Spencer Gulf is impoverished in terms of overall species richness but relatively rich in species which are either endemic or have tropical affinities. Other Areas of Significance − Yatala Harbour Aquatic Reserve (1,426 hectares). Samphire flats, flushed by extremely high spring rides, intertidal sand and mudflats; subtidal seagrass meadows; coarse sand and shell channel areas. − Blanche Harbour-Douglas Bank Aquatic Reserve (3,160 hectares). Intertidal mangrove area; intertidal sand and mudflats; subtidal seagrass meadows; coarse sand and shell channel areas. − Winninowie Conservation Park (Chinamans Creek). Pied Cormorants breed at Chinamans Creek. 1.2 − Physical All of the far Northern Spencer Gulf region can be considered as physically significant owing primarily to its nature as an inverse estuary which contributes to the biological properties of the region. Page 123 SPENCER GULF REGION – WINNINOWIE BIOUNIT − 2 2.1 Sedimentologically, the seagrass meadow acts as a major subtidal carbonate "factory", with high rates of in-situ carbonate production and post-mortem skeletal accumulation (Davies 1970, Patriquin 1972, Gostin et al. 1984). Also trapped are terrigenous and aeolian detrital grains, as well as both terrigenous and calcareous muds. The Corallinaceae are important carbonate producers, particularly Lithothamnium, Jania and Corallina species. Benthic and epiphytic foraminifers are also important contributors to the sediment. Other sessile and vagile epifauna which contribute to bed sediment are encrusting bryozoa, gastropods, hydroids, echinoderms and ascidians. OTHER VALUES Commercial Fisheries Major single species fisheries which operate in this region include the Western King Prawn fishery. There is also an extensive marine scalefish fishery in this region which targets, among other species, Snapper, King George Whiting and Shark. Trawling for Western King Prawn occurs further away from the coast. No abalone is commercially harvested within this region. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of the Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Marine Scalefish Fisheries This biounit encompasses 2 fishing zones: Fishing Zone 21 and 11. In the southern waters of this biounit, from Wood Point north to Point Douglas, including Germein Bay and False Bay (ie. Fishing Zone 21), 57 and 61 commercial licence holders fished during 1995/96 and 1996/97. License holders expended approximately 4,624 and 4,791 boat days effort fishing these waters during 1995/96 and 1996/97, with a total catch of 660899 kg and 869,656 kg, respectively (or 6.36% and 8.58% of the total catch for the marine scalefish fishery in South Australian waters). In the northern waters of this biounit, north of Point Douglas (ie. Fishing Zone 11), fishing effort is significantly lower. A total of 7 and 6 commercial licence holders fished approximately 209 and 130 boat days effort fishing these waters during 1995/96 and 1996/97, with a total catch of 10829 kg and 11,730 kg, respectively (or 0.10% and 0.12% of the total catch for the marine scalefish fishery in South Australian waters. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − 2.2 Port Augusta: 9 restricted marine scalefish, 5 unrestricted marine scalefish Aquaculture Present aquaculture activities in this region include: R&D lease (30ha) for the culture of finfish in sea cages at Fitzgerald Bay and in the outflow channel of the Port Augusta power station, as well as on the land adjacent to this. A single 792 ha lease application in Fitzgerald Bay has recently been lodged by the NSGAE. The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: Far Northern Spencer Gulf Policy Area − Fitzgerald Bay Management Zone (waters within Fitzgerald Bay) – zoned for sustainable aquaculture development. Licenses will be considered for a maximum of 100ha of aquaculture within development within this zone. − Douglas Management Zone (coastal waters north of Douglas Point, north to just south of Douglas Bank Aquatic Reserve) – zoned for R&D intertidal shellfish culture. Licenses will be considered for a maximum of 10ha of intertidal oyster culture within this zone, upon successful completion of an R&D program. − Patterson Management Zone (coastal waters of Port Patterson) – zoned for R&D aquaculture development. Licenses will be considered for a maximum of 16ha of R&D aquaculture development. Aquaculture will be restricted to Pacific Oyster culture within the inlet channel of the Port Augusta Power Station and aquaculture requiring supplementary feeding within the inlet and outlet channel of the power station. Page 124 SPENCER GULF REGION – WINNINOWIE BIOUNIT − Augusta Zone (all remaining waters, from Point Lowly to Ward Spit, to Port Augusta, not covered by above zones) – zoned to preserve existing uses and values. Licenses will not be considered for aquaculture development within this zone. − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); and regular research and monitoring of larval fish stocks. 2.5 2.3 Adjacent Land Use Recreation and Tourism National and Conservation Parks Fishing − − − 2.4 − − − Port Augusta: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally, Southern Calamari, Mulloway and Yellowtail Kingfish. There are artificial reefs located near Port Augusta (tyre modules), Port Pirie (tyre modules), Port Germein (sunken pipes) and Port Broughton (car bodies). There are three artificial reefs near Whyalla (tyre modules). − Winninowie Conservation Park (Chinamans Creek) (7,847 ha) (SANPWS 1996). Point Jarrold Sanctuary. Agriculture/Industry − Much of the adjacent land in this biounit is used for agriculture. − Port Augusta is a major industrial centre with port facilities. Urban Centres Tourrism − Port Augusta (population 15,291). Port Augusta: boating. − Port Augusta has permanent coastal moorings for recreational and commercial craft. Scientific Research and Education Chinaman’s Creek Research Station is situated on the shores of Spencer Gulf, in the Winninowie Conservation Park. The field station encompasses both research facilities and accommodation. The field research station was a major focus for marine studies in northern Spencer Gulf, particularly in the 1970s, for a range of oceanographic, geomorphological and marine ecological and benthic studies. During the 1980s the field station was utilised for ongoing climatological and oceanographic monitoring, and also, fisheries research into benthic infauna, Blue Swimming Crabs, and a range of commercial marine scalefish species. In recent years, research activity at the station has declined, however, ongoing meteorological and oceanographic monitoring is still conducted. Northern Spencer Gulf has been the subject of major research and scientific investigations, both geoscientific and biological, over several decades. − Other Uses Army Training Area (Fitzgerald Bay to Port Augusta). 2.6 Features Significant Cultural and Historical − Aboriginal Fitzgerald Bay: Aboriginal fish trap. − European Not known. 3 CURRENT CONSERVATION STATUS OF THE WINNINOWIE BIOUNIT − − Marine Reserves Blanche Harbour-Douglas Bank (3,160 ha) Yatala Harbour (1,426 ha) − Marine Parks None − Netting Closures Douglas Bank (all waters of Spencer Gulf north of a line east west through the Douglas Bank beacon). Page 125 SPENCER GULF REGION – WINNINOWIE BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE WINNINOWIE BIOUNIT Far Northern Spencer Gulf − Prime IUCN Conservation Values: rare and endangered species/habitats, aesthetics, biodiversity, social values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (rare biogeographic qualitiessubtropical element in marine fauna and flora, largest area of coastal and marine wetlands in SA), ecological (essential ecological processes, range of wetland habitats, large areas of mangroves, seagrasses, saltmarshes, numerous tidal estuaries, key nursery, feeding areas for economic species – Western King Prawn, marine scalefish, threatened waterbirdsOrange-bellied Parrot, Hooded Plover, Whitebellied Sea-Eagle, Osprey, Little Egret, Eastern Curlew, Fairy Tern, Eastern Reef Egret, Spotted Crake), economic (fisheries, tourism), social (aesthetic values, recreation), scientific (Chinaman’s Creek research station, ecological, fisheries, geomorphological research and monitoring), national/international (international importance for shorebirds and Wetland of National Importance-upper Spencer Gulf wetlands, potential for RAMSAR listing), practicality (insulation, compatibility-adjacent to Winninowie Conservation Park and Army Training Area). Page 126 SPENCER GULF REGION – TIPARRA BIOUNIT XV MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE TIPARRA BIOUNIT This biounit extends from Point Riley on the eastern side of central Spencer Gulf, to Island Point (near Port Victoria) and covers an area of 243,228 ha. The biounit faces westerly into Spencer Gulf. MARINE BIOGEOGRAPHY 1 − OCEANOGRAPHY This is a predominantly low to moderate wave energy area. Major Benthic Communities • 2 GEOLOGY AND GEOMORPHOLOGY22 COASTAL The west coast of Yorke Peninsula in Spencer Gulf is more exposed than the east coast. Much of the coast is comprised of long sandy beaches and shore platforms associated with these, with a single dune or narrow belt of dunes behind. Notable exceptions are the limestone cliffs in the Pt Turton/Point Souttar area; the rocky coastlines at Port Victoria, Point Pearce and north of Point Riley; the clay cliffs at Balgowan and Moonta Bay; the shallow deeply indented bay at Port Broughton; and the low calcrete cliffs to be found at various locations. From Tickera to Point Riley there are stable clay or limestone cliff slopes. At Wallaroo and North Beach there is a wide dune belt followed by aelonite and limestone cliffs from Wallaroo to the northern end of Moonta Bay. Some tidal swamps with mangroves and samphire flats occur at Warburto Point. Moonta Bay consists of a wide dune belt and limestone cliffs. 3 BIOLOGY Of the total inshore subtidal habitats mapped in this biounit (103,185 ha), seagrass meadows comprise 83,912 ha (81.3%), sandy bottoms comprise 14,782 ha (14.3%), and reefs comprise 4,491ha (4.4%). − • − Macroalgal Subtidal rocky shore communities in this region (eg. Point Riley) are dominated by species of Sargassum (S.linearifolium, S.podacanthum), with Scaberia agardhii as a sub-dominant. The understorey is dominated by the prostrate Lobophora variegata, and a mixed-red algal community (Botrycladia, Rhabdonia, Echinothamnion, Jeanneretia). Seagrasses Extensive seagrass meadows occur in Wallaroo and Moonta Bay (eg. Tiparra reef). Sandy sediments in this region are commonly dominated by Posidonia sinuosa, Amphibolis antarctica and Heterozostera tasmanica. Coastal and Offshore Islands (or Reefs) − − − Riley Shoal, Moonta Shoal. Tiparra Reef. Bird Islands (Green Island). − Rivers/Estuaries None. Major Inshore Habitats − Major intertidal habitats in the region include mostly low rocky shores, bays and sandy beaches. 22 From Yorke Coast Protection District Study Report (Wynne 1980). Page 127 SPENCER GULF REGION – TIPARRA BIOUNIT MARINE CONSERVATION VALUES 1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES 1.1 AND Warburto Point − Biological Tiparra Reef Tiparra Reef is an extensive seagrass-reef shoal system in Moonta Bay, that extends along the western coastline of Yorke Peninsula, from Cape Elizabeth to Warbuto Point and Bird Islands. Like the seagrass-reef shoal system of Orontes Shelf in Gulf St Vincent, the calcreted Pleistocene shell bed forms extensive flat rocky surfaces, or low erosional escarpments and provides excellent habitat for a diversity of marine life, including sponges, ascidians, and reef molluscs, and is also an outstanding mixed fishing ground. The diversity and productivity of the area, particularly on the reefs, is enhanced by the tidal currents of the northern gulf. Tiparra Reef is presently the major commercial fishing ground for Greenlip Abalone (Haliotis laevigata) in South Australia, with catches in the area representing approximately 25-30% of the total South Australian catch for this species (or 65-80% of the total catch for the Central Zone). A conservation reserve was proposed for the reefs at Cape Elizabeth by the former SA Department of Fisheries in 1980. Bird Islands Conservation Park − − The seagrass meadows of this biounit represent the second largest areas in Spencer Gulf. These extensive seagrass meadows flourish in the shallow waters, generally in waters less than 15m, and provide the basis for the significant productivity of the region in terms of fisheries and prawn production. Seagrasses cover a total area of approximately 5,512 km2 in Spencer Gulf, of which 4,138 km2 is located in northern Spencer Gulf (ie. north of Point Riley). Together, the seagrasses of Spencer Gulf represent 57% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the central northern reaches of the gulf (ie. Yonga Biounit, 248,596 ha), in the Tiparra Reef region (ie. Tiparra Biounit, 83,912 ha) and the Port Lincoln region (ie. Jussieu Biounit, 56,956 ha). Consists of two small islands that provide an important breeding and feeding ground for bird life, particularly Pied Cormorants, Crested Terns, Caspian Terns, Pacific Gulls and Silver Gulls. Tiparra and Cape Elizabeth − 1.2 Reefs are known for their great diversity of fish. A conservation reserve was proposed for Cape Elizabeth in 1980. Physical Geological Monuments − 2 2.1 Seagrass Meadows Contains samphire flats and some mangroves and supports a diverse bird population. It is an important breeding and feeding ground for bird life, particularly Pied Cormorants and Caspian Terns. Port Hughes-Port Moonta: basement rocks on the foreshore of Moonta Bay. It is on the Register of the National Estate. OTHER VALUES Commercial Fisheries A wide variety of commercial fishing occurs in the coastal and offshore waters of this biounit. Single species fisheries include Western King Prawn, and Abalone. There is a large marine scalefish industry. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of the Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27025 and 25369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Page 128 SPENCER GULF REGION – TIPARRA BIOUNIT 2.2 Abalone The Tiparra Biounit, particularly Tiparra Reef, is the major fishing ground for Greenlip Abalone in South Australia. In 1994/95 and 1995/96 a total of 96,324 and 117,924 kg of Greenlip was harvested within this region (ie. MapCode 21H, 21A-G, Moonta Bay, Tiparra Reef), and represented 67.1% and 82.5% of the total Greenlip Central Zone catch (or 25.57% and 31.50% of the total catch for Greenlip in South Australian waters). In contrast, limited amounts of Blacklip was harvested within this region. Aquaculture An intertidal oyster farm operated at Bird Island for a number of years but has since closed. A large pond based prawn farm also operated during the mid to late 1970s adjacent to Port Broughton. There is an approved 10ha oyster lease in Port Victoria Bay. The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: Northern Yorke Peninsula Policy Area Marine Scalefish Fisheries During 1995/96 and 1996/97, 42 and 41 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish) caught commercial marine scalefish species from the Tiparra Biounit (ie. Fishing Zone 32), respectively. License holders expended approximately 2547 and 2,272 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 32) represented 145,970 kg in 1995/96 and 144,878 kg in 1996/97(or 1.40% and 1.43% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Port Broughton: 1 restricted marine scalefish, 15 unrestricted marine scalefish, 1 Spencer Gulf Prawn, 2 experimental crab − Moonta Bay: 2 Abalone, 2 Rock Lobster, 2 abalone, 7 unrestricted marine scalefish − Port Hughes: 1 Abalone, 1 abalone, 3 restricted marine scalefish, 8 unrestricted marine scalefish − Wallaroo: 5 restricted marine scalefish, 20 unrestricted marine scalefish, 2 Prawn (Spencer Gulf) − Balgowan: 2 unrestricted marine scalefish − Tickera: 3 unrestricted marine scalefish − Chinaman scalefish Wells: 1 unrestricted − Wallaroo Zone (coastal waters, from just north of Fisherman Bay, south to Cape Elizabeth, excluding Offshore Tickera Management Zone and Broughton Management Zone) – zoned to preserve existing values and uses. Licenses will not be considered for aquaculture development within this zone. Central Yorke Peninsula Policy Area − Hardwicke Bay Zone (waters of Hardwicke Bay, from Cape Elizabeth to Corny Point, and excluding the Port Victoria Management Zone) – zoned to preserve existing uses and values. Licenses will not be considered for aquaculture development within this zone. − Port Victoria Management Zone (coastal waters of eastern Wardang Island to Point Pearce) – zoned to facilitate an intertidal oyster culture industry. Licenses will be considered for an additional 40ha of intertidal oyster culture within this zone. 2.3 Recreation and Tourism Fishing − Wallaroo and Port Hughes: boat, jetty and rock fishing. Major species: King George Whiting, Yellowfin Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Greenback Flounder, Blue Swimming Crab, Tommy Rough, Trevally, Silver Drummer and Southern Calamari. − There is an artificial reef near Port Broughton (car bodies) and Wallaroo (tyre modules). marine Page 129 SPENCER GULF REGION – TIPARRA BIOUNIT 2.6 Tourism Significant Cultural and Historical Features − Wallaroo and Port Hughes: fishing, boating, camping, swimming. − The Bamboos camping Reserve. − Tiparra Rocks: camping reserve. − SCUBA diving: Port Hughes and Wallaroo jetties are recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The pylons are covered in marine life and are of great site for underwater photography. 2.4 − Scientific Research and Education Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Aboriginal − European Shipwrecks − `San Miguel’ (1864-1865): a three-masted iron barque which ran on to the Tiparra Reef near Wallaroo. 3 CURRENT CONSERVATION STATUS OF THE TIPARRA BIOUNIT − Marine Reserves None Marine Parks None − Netting Closures None − 2.5 Adjacent Land Use National and Conservation Parks − Bird Islands Conservation Park, north of Warbuto Point (8 ha). Agriculture/Industry − 4 Most adjacent land in this biounit is used for agriculture. Urban Centres − Wallaroo (population 2,300). Wallaroo is the economic epicentre for the copper triangle towns. − Moonta (population 2,500). − Both centres have a permanent coastal mooring facility for commercial and recreational craft, as does Point Turton. The most important areas of cultural significance include the Cape Elizabeth/Tiparra Springs dunes and in the dunes north of Moonta Bay. Other west coast areas of occupation, where evidence is know to exist, include the dunes between Port Hughes and Cape Elizabeth and in the dunes south of Port Victoria. AREAS OF HIGH CONSERVATION VALUE IN THE TIPARRA BIOUNIT Tiparra Reef-Tiparra Bay-Cape Elizabeth − Prime IUCN Conservation Values: biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, geological monument-Port Hughes), ecological (diversity of marine habitatsmangroves, seagrass meadows, reefs, nursery and feeding areas for economic species-marine scalefish, breeding sites for Pied Cormorants, Crested Terns, Caspian Terns, Pacific Gulls and Silver Gulls), economic (Greenlip Abalonemajor fishing ground in SA, marine scale fisheries, tourism), social (aboriginal cultural sites, historic shipwreck-`San Miguel’, recreation), scientific (abalone, marine scalefish research and monitoring), national (Register of the National Estate-Port Hughes), practicality (insulation, accessibility, compatibility – adjacent to Bird Islands Conservation Park). Page 130 SPENCER GULF REGION – TIPARRA BIOUNIT Moonta Bay-Bird Tiparra Bay23 − Islands-Tiparra Reef- Prime IUCN Conservation Values: biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, geological monument-Port Hughes), ecological (diversity of marine habitatsmangroves, seagrass meadows, reefs, nursery and feeding areas for economic species-marine scalefish, breeding sites for Pied Cormorants, Crested Terns, Caspian Terns, Pacific Gulls and Silver Gulls), economic (Greenlip Abalonemajor fishing ground in SA, marine scale fisheries, tourism), social (aboriginal cultural sites, historic shipwreck-`San Miguel’, recreation), scientific (abalone, marine scalefish research and monitoring), national (Register of the National Estate-Port Hughes), practicality (insulation, accessibility, compatibility – adjacent to Bird Islands Conservation Park). 23 The reefs at Cape Elizabeth were nominated for establishment as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, for conservation purposes (Wynne 1980). Page 131 SPENCER GULF REGION – WARDANG BIOUNIT XVI MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE WARDANG BIOUNIT This biounit extends from Island Point (near Port Victoria) on the eastern side of central Spencer Gulf to Corny Point, on the southwestern tip of Yorke Peninsula and covers an area of 285,583ha. The biounit faces westerly into Spencer Gulf. mangrove trees, and shallow sand and mud flats offshore. Goose Island lies off the north coast. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY 3 This is a predominantly low to moderate wave energy area, with Wardang Island also being exposed to high wave energies. Wave energy ranges from low near Point Turton, to moderate from Point Souttar to Corny Point. 2 GEOLOGY AND GEOMORPHOLOGY24 COASTAL The coastal geomorphology is dominated by limestone cliffs alternating with wide dune belts. From Cape Elizabeth to Balgowan there is a wide dune belt followed by eroding clay cliffs. From Balgowan to Point Pearce there is a wide dune belt and small section of limestone cliff. Small tidal swamps occur north of Port Victoria, followed by small dunes and wide sandy beaches to Point Turton, extending into a larger dune belt in Hardwicke Bay. At Port Rickaby, the dunes are well vegetated between The Bluff and Port Rickaby and include a fine development of open-heath and also an unusually large range of vegetation types for such a narrow strip of land (7 km long and averaging 300 metres wide). From Point Turton to Point Souttar there are aelonite and limestone cliffs followed by wide dunes to Corny Point. At Leven Beach Conservation Park there is a unique parallel dune formation with dense natural vegetation. Wardang Island has a medium to high energy coast on its west side, and a low energy coast on its eastern, lee side. It contains the wide variety of coastal types to be expected with the different wave energy levels, and this makes it an invaluable miniature of the Yorke Coast. The western coast contains several pocket beaches separated by rocky headlands, and there are some large sand drifts behind these. The low lying and swampy east coast has samphire areas and a few scattered BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly low rocky shores and sandy beaches. − Of the total inshore subtidal habitats mapped in this biounit (146,919 ha), sandy bottoms comprise 65,722 ha (44.7%), reefs comprise 54,739 ha (37.3%), and seagrass meadows comprise 26,458 ha (18.0%). Major Benthic Communities • − Macroalgal On exposed rocky shores, subtidal communities (ie. west coast Wardang Island) are dominated by a mixed-Cystophora (ie. Cystophora expansa, C.monolifera, C.monoliformis) and Sargassum community (ie. Sargassum sonderi, S.spinuligerum, S.heteromorphum) and the prostrate brown alga, Lobophora variegata. On moderately exposed coasts (ie. east coast Wardang Island, Port Minlacowie), subtidal communities are dominated by Scaberia agardhii, species of Cystophora (C.botryoides, C.expansa), Osmundaria prolifera, mixed-Sargassum species (S.linearifolium, S.lacerifolium, S.spinuligerum, S.heteromorphum), Cladurus elatus and Cladostephus. 24 From Yorke Coast Protection District Study Report (Wynne 1980). Page 132 SPENCER GULF REGION – WARDANG BIOUNIT • − Seagrasses − Several species of protected seabirds breed on islands of the Wardang Group, including Little Penguins (on Goose and Green Island), Blackfaced Cormorants (on Rocky Islet, White Rocks), Pied Cormorants, Silver Gulls and Pacific Gulls (on Little Goose Island), Crested Terns (on Goose, Rocky and Seal Rocks) and Caspian Terns (on Wardang Island) (Copley 1996). − The intertidal reef areas at Barkers rocks contain a wide variety of intertidal life and are popular with educational groups. Extensive seagrass meadows occur in Hardwicke Bay and Port Victoria. Sandy sediments are commonly dominated by Posidonia sinuosa, P.angustifolia and Amphibolis antarctica in shallower waters. Coastal and Offshore Islands (or Reefs) − Wardang Island, Goose Island and Green Island. 1.2 MARINE CONSERVATION VALUES Physical Geological Monuments 1 1.1 − − − SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND − Wardang Island: volcanics, Precambrian, Permian glacials and Cainozoic sediments. The island is also on the Register of the National Estate. − Cliff Point (Wardang Island): cliff section unconformities. − Port Victoria: foreshore of Proterozoic rocks. − Point Turton: coastal cliffs. Features of significance include an unconformity and Permian glacial sediments with the type locality for Point Turton Limestone. Biological White Rocks (Wardang Island and Goose Island Conservation Park) is a haul out site for Australian Sea Lions. Colony numbers have fluctuated from 35 sea lions, recorded in 1978 (Robinson & Dennis (1988), to 24, recorded in 1990 (Gales 1990). The subtidal areas of Wardang Island have considerably large and diverse communities of algae, seagrasses, benthic communities and fish. The shipwrecks appear to provide refuge for a wide variety of fish species. Wardang Island Conservation Park is on the register of the National Estate. 2 2.1 Goose Island Aquatic Reserve off the northern end of Wardang Island (54 hectares) has a submerged reef connecting it with Wardang Island. The waters surrounding Goose Island support dense beds of seagrasses Posidonia and Amphibolis. The rocky areas to the west and northwest of the island support a brown algal community dominated by Cystophora and Sargassum species. The islets of the reserve can offer shelter from the wind in any direction and this feature is reflected in the distribution of the benthic marine organisms around the reserve. Fishing in the reserve is not permitted but line fishing near the reserve can be rewarding and many species of fish are reported to have been caught in the area including Snook, Salmon, King George Whiting, Garfish, Squid, Bronze Whaler Shark, Tommy Ruff, Sweep, Trevally and Leatherjackets. OTHER VALUES Commercial Fisheries A wide variety of commercial fishing occurs in the coastal and offshore waters of this biounit. Single species fisheries include Western King Prawn, Southern Rock Lobster and Greenlip Abalone. There is also a large marine scalefish industry in the region. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of the Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Page 133 SPENCER GULF REGION – WARDANG BIOUNIT Southern Rock Lobster In 1995/96 and 1996/97 a total of 3 and 2 licensed operators fished in the Wardang Biounit (ie. Fishing Zone 33). Abalone Only Greenlip Abalone is presently commercially harvested within this biounit. In 1994/95 and 1995/96 a total of 34,719 and 7,059 kg of Greenlip was harvested within this region (ie. MapCode 22A, 24A, Port Victoria, Hardwicke Bay region), and represented 24.2% and 4.9% of the total Greenlip Central Zone catch (or 9.22% and 1.89% of the total catch for Greenlip in South Australian waters). 2.2 At present 3 intertidal Pacific oyster leases have been approved in the Port Victoria - Wardang Island area. One onshore abalone farm has also been approved in this region and others may well follow given the suitability of large areas of land adjacent to the coast. The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends the following aquaculture development in the region: Central Yorke Peninsula Policy Area − Port Victoria Management Zone (coastal waters of eastern Wardang Island to Point Pearce) – zoned to facilitate an intertidal oyster culture industry. Licenses will be considered for an additional 40ha of intertidal oyster culture within this zone. − Hardwicke Bay Zone (waters of Hardwicke Bay, from Cape Elizabeth to Corny Point, and excluding the Port Victoria Management Zone) – zoned to preserve existing uses and values. Licenses will not be considered for aquaculture development within this zone. Marine Scalefish Fisheries During 1995/96 and 1996/97, 88 and 74 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish categories) caught commercial marine scalefish species from the Wardang Biounit (ie. Fishing Zone 33), respectively. License holders expended approximately 4,024 and 3,660 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 33) represented 172,023 kg in 1995/96 and 218,560 kg in 1996/97(or 1.65% and 2.16% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Point Turton: 1 Abalone, 2 Rock Lobster 1 abalone, 1 restricted marine scalefish, 9 unrestricted marine scalefish − Port Victoria: 1 Rock Lobster, 6 restricted marine scalefish, 13 unrestricted marine scalefish − Hardwicke Bay: 1 restricted marine scalefish, 6 unrestricted marine scalefish − Port Minlacowie: 4 restricted marine scalefish 3 unrestricted marine scalefish − Aquaculture 2.3 Recreation and Tourism Fishing − Port Victoria and Wardang Island: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Blue Swimming Crab, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Hardwicke Bay, Point Turton and Point Souttar: boat and jetty (Point Turton) fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Snapper, Snook, Garfish, Tommy Rough and Southern Calamari. Tourism Port Rickaby: 2 unrestricted marine scalefish, 3 restricted marine scalefish − Port Victoria and Wardang Island: fishing, boating, camping, historic area, including shipwrecks (underwater trail on Wardang island), and SCUBA diving and snorkelling off Wardang Island. Charter boats operate to Wardang Island. Page 134 SPENCER GULF REGION – WARDANG BIOUNIT − Port Rickaby: fishing, boating, camping. − Bluff Beach and Parsons Beach: fishing, boating, camping. − Hardwicke Bay, Point Turton, Point Souttar: fishing, boating, swimming, camping. − 2.4 − − SCUBA diving: Wardand Island and Point Turton jetty are recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Wardang Island is recognised for wreck diving and has nine shipwrecks around the island, eight of which form the Wardang Island Maritime Heritage Trail (see below). White Rocks at the northern end of Wardang Island is a popular site for diving with sea lions. Point Turton jetty, like Port Hughes and Wallaroo jetties, contains abundant marine life and is popular and accessible spot for underwater photography. Scientific Research and Education Wardang Island is used extensively for educational purposes by various schools, institutions and clubs. In particular, Goose Island Conservation Park and Aquatic Reserve, off Wardang Island's north coast, is used on a regular basis by Scotch College as an educational field station. The College has an annual licence to use the island and is required to conserve the flora and fauna. The surrounding waters were proclaimed an Aquatic Reserve at the school's request. The park also includes White Rocks Island. 2.5 National and Conservation Parks − Goose Island Conservation Park (20 ha) and Aquatic Reserve (54 ha). − Leven Beach Conservation Park (494 ha). Agriculture/Industry − A beach and wave cut platform at Barker Rocks, south of Port Rickaby, is regularly used by educational and school groups. − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Most adjacent land in this biounit is used for agriculture. Urban Centres − Port Victoria (population 250). − This centre has a permanent coastal mooring facility for commercial and recreational craft, as does Point Turton. 2.6 Features Significant Cultural and Historical Aboriginal − Wardang Island is owned by the Aboriginal Lands Trust and is leased to the Point Pearce Community Council. The council has considered a sub-lease to the Minister of Education, and the Department of Further Education has established an outdoor education based camp on the island. − The most important areas of cultural significance include the Cape Elizabeth/Tiparra Springs dunes and in the dunes north of Moonta Bay. Other west coast areas of occupation, where evidence is know to exist, include the dunes between Port Hughes and Cape Elizabeth and in the dunes south of Port Victoria. The waters surrounding Wardang Island comprise one of the most significant areas of maritime heritage in South Australia. The wrecks along the recently established underwater heritage trail are both significant educational site as well as sites for ongoing maritime research. − Adjacent Land Use European − Port Victoria is the last of the windjammer ports. Page 135 SPENCER GULF REGION – WARDANG BIOUNIT Shipwrecks − The Wardang Island Maritime Heritage Trail consists of 8 shipwrecks (with underwater interpretative plaques): − `Songvaar’ (1884-1912): a three-masted iron ship whose own anchor pierced its hull. − `Moorara’ (1909-1975): a three-masted schooner which sank during a "blow" while at anchorage off the island. − `S.S. Australian’ (1879-1912): a schoonerrigged iron screw steamer which struck the south-eastern corner of the island. − `MacIntyre’ (1877-1927): a three-masted iron schooner which struck a rock off the southern end of the island. − `Monarch’ (1871-1909): a three-masted wooden schooner which struck rocks on the southern end of the island. − `Notre Dame D'Arvor’ (1902-1920): a threemasted steel barque which grounded on rocks on the south-western corner of the island. `S.S. Investigator’ (1882-1918): a schoonerrigged iron screw steamer, which grounded on rocks to the south-west of the island. − `Aagot’ (1882-1907): a three-masted iron barque which ran aground on rocks on the western side of the island. 3 CURRENT CONSERVATION STATUS OF THE WARDANG BIOUNIT − Marine Reserves Goose Island (54 ha). − Marine Parks None. AREAS OF HIGH CONSERVATION VALUE IN THE WARDANG BIOUNIT Wardang Island- Port Victoria − − − 4 Prime IUCN Conservation Values: education, biodiversity, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, geological monuments-Wardang Island, Cliff Point, Port Victoria), ecological (diversity of marine habitats, seagrass meadows, reefs, nursery and feeding areas for economic species – marine scalefish, haul out site for Australian Sea Lions, breeding areas for Little Penguins, Black-faced Cormorants, Pied Cormorants, Silver Gulls, Pacific Gulls, Crested Terns and Caspian Terns, Australian Sea Lions), economic (Greenlip Abalone, marine scale fisheries, tourism), social (shipwrecks – Maritime Heritage Trail, recreation, educationGoose Island field station), scientific (marine scalefish research and monitoring), national (Register of the National Estate), practicality (insulation, compatibility-adjacent to Wardang Island Conservation Park, accessibility). Point Turton-Leven Beach − Prime IUCN Conservation Values: social values, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, geological monument-Point Turton), ecological (nursery and feeding areas for economic species-marine scalefish), economic (prawn, marine scale fisheries, tourism), social (recreation), scientific (prawn, marine scalefish research and monitoring), practicality (insulation, compatibility -Leven Beach Conservation Park, accessibility). Netting Closures Port Victoria (in those waters that exceed 5 m in depth contained within a line from Point Gawler to the north west point on Goose Island, then to Reef Point). Page 136 SPENCER GULF REGION – PONDALOWIE BIOUNIT XVII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE PONDALOWIE BIOUNIT This biounit extends from Corny Point to West Point (on the southwestern tip of Yorke Peninsula) and covers an area of 22,130 ha. The biounit faces west into lower Spencer Gulf. MARINE BIOGEOGRAPHY 1 − OCEANOGRAPHY Wave energy range is high from Corny Point to Cape Spencer. 2 GEOLOGY AND GEOMORPHOLOGY 25 COASTAL The coastal geomorphology is dominated by limestone cliffs alternating with wide dune belts. Corny Point is an area of aelonite and limestone cliffs. From Daly Head to Formby Bay there is a wide dune belt and limestone cliff slopes. Dunes located between Daly Head and Little Lizard Bay are by far the most extensive parabolic dunes in the region. The seaward portion consists of unvegetated mobile sand in the form of a sheet drift approximately 7km long by 1km wide. This partly overlies and is backed by an almost equal area of stable vegetated parabolic dunes containing a diverse flora. Brown's Beach and Pondalowie Bay are also areas with wide dune belts. At Cape Spencer there are aelonite and limestone cliffs, followed by a wide dune belt at Marion Bay. 3 BIOLOGY Major Inshore Habitats − Of the total inshore subtidal habitats mapped in this biounit (179,964 ha), sandy bottoms comprise 15,077 ha (83.9%), reefs comprise 2 862 ha (15.9%), and seagrass meadows comprise 25 ha (0.1%). Major Benthic Communities • Macroalgal − On exposed rocky shores (eg. Berry Bay, Formby Bay), subtidal communities are dominated by Ecklonia radiata, Scytothalia dorycarpa and a understorey of red algae (Plocamium, Peysonnelia, Phacelocarpus) and crustose corallines. On less exposed shores (eg Daly Head), the deeper subtidal communities are dominated by Carpoglossum confluens, Homeostrichus sinclairii, Cystophora grevillea, C.platylobium and mixed reds (Phacelocarpus, Cladurus elatus, Gracilaria). In shallower areas, reefs are dominated by Ecklonia radiata, Acrocarpia paniculata, Cystophora monoliformis and mixed coralline algae (Lithothamnion, Haliptilon, Metagoniolithon, Cheilosporum, Jania). In sheltered areas (eg. Royston Head) reefs are dominated by species of Cystophora (C.monilifera, C. moniliformis), Ecklonia radiata, Caulerpa cactoides, Scytothalia dorycarpa, and Sargassum verruculosum in shallow areas. In deep areas, reefs are dominated by species of Sargassum (S.fallax, S.sonderi, S.linearifolium), Ecklonia radiata, and mixed fucoids (Cystophora moniliformis, Myriodesma integrifolium, Micropeuce, Areschougia). Major intertidal habitats in the region include mostly exposed rocky shores and sandy beaches. 25 From Yorke Coast Protection District Study Report (Wynne 1980). Page 137 SPENCER GULF REGION – PONDALOWIE BIOUNIT • − 1.2 Seagrass Seagrass meadows occur in Formby Bay and West Bay. Sandy sediments (ie. Dunn Point, West Bay) dominated by Amphibolis antarctica (to 13m) and Posidonia sinuosa, and also, Heterozostera tasmanica, Halophila australis and the green alga, Caulerpa scapelliformis. Physical Geological Monuments − Corny Point: unconformity sediments. − Browns Beach: Proterozoic basement rocks. Proterozoic underlying basement Cainozoic Coastal and Offshore Islands (or Reefs) − 2 Daly Head Island, Pondalowie Islands (Royston, Middle Islands - part of Innes National Park). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological − The intertidal reef areas at Gleesons Landing near Daly Head contains a wide variety of intertidal life. − Innes National Park preserves the largest area of natural bushland remaining on the Yorke Peninsula, and preserves the habitat of the Western Whipbird. It is characterised by a sandy undulating plain with dunes and salt lakes, or low cliffs along the coastline. The magnificent and spectacular coastal scenery is one of the major attractions of this park, which includes cliffs, wave cut platforms, rocky headlands and sandy beaches. Typical coastal dune and cliff-top vegetation is backed by mallee and teatree scrub. It is still possible to see the remains of the shipwreck `Ethel' near Reef Head. Daly Head, Royston, Middle Islands are included in the national park. Little Penguins and Silver Gulls breed on Royston and Middle Islands (Pondalowie Bay) (Copley 1996). 2.1 OTHER VALUES Commercial Fisheries A wide variety of commercial fishing occurs in the coastal and offshore waters of this biounit. Single species fisheries include Western King Prawn, Southern Rock Lobster and Abalone. There is also a significant marine scalefish industry within this region. Western King Prawn This biounit is located within the waters of the Spencer Gulf prawn fishery, which comprises 39 license holders (ie. Boats). All vessels fish within the waters of the Spencer Gulf biounits (ie. Jussieu, Dutton, Franklin, Yonga, Tiparra, Wardang, Pondalowie, Spencer). In 1995/96 and 1996/97 a total of 1,811,598 and 1,646,799 kg was caught for this fishery, with a total effort of 27,025 and 25,369 hours, respectively (or 79.78% and 81.37% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster In 1995/96 and 1996/97 a total of 19 and 19 licensed operators fished in the south western and southern Yorke Peninsula (and Investigator Strait) region (ie. Fishing Zone 40), catching approximately 71,795 and 64,785 kg of lobsters, respectively (or 1.40% and 1.27% of the total catch for Southern Rock Lobster in South Australian waters). Page 138 SPENCER GULF REGION – PONDALOWIE BIOUNIT Abalone Warooka Policy Area Blacklip Abalone and some Greenlip Abalone is presently commercially harvested within this biounit (ie. MapCode 23A-D, Corny Point to Foul Bay region). In 1994/95 and 1995/96 a total of 4,656 and 3,504 kg of Blacklip was harvested within this region, and represented 11.8% and 8.3% of the total Blacklip Central Zone catch (or 0.94% and 0.76% of the total catch for Blacklip in South Australian waters). Greenlip Abalone figures are unavailable due to confidentiality constraints. − 2.3 − Corny Point and Berry Bay: boat, beach and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Tommy Rough, Trevally, Toothbrush, Leatherjacket, Silver Drummer and Southern Calamari. − Daly Head: beach and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Mulloway, Sweep, Tommy Rough. Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Browns Beach: beach fishing. Major species: Black Bream, Yelloweye Mullet, Australian Salmon and Tommy Rough. − Pondalowie Bay: boat, rock and beach fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Southern Rock Lobster, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − West Cape: beach and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Sweep, Tommy Rough and Toothbrush Leatherjacket. − Cape Spencer: beach and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Sweep, Garfish, Tommy Rough, Toothbrush Leatherjacket and Silver Drummer. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Pondalowie: 2 Rock Lobster − Corny Point: 3 Rock Lobster, 11 unrestricted marine scalefish 2.2 Aquaculture There is currently no aquaculture development within this region. The coastline south of Corny Point is exposed to waves and swell, and is boarded by high cliffs, extensive dunal systems and/or National Park. Because of this aquaculture development is unlikely through most of this region. The Spencer Gulf Aquaculture Management Plan (PIRSA 1996) recommends no aquaculture development within the region: Recreation and Tourism Fishing Marine Scalefish Fisheries During 1995/96 and 1996/97, 54 and 51 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the in the south western and southern Yorke Peninsula (and Investigator Strait) region (ie. Fishing Zone 40), respectively. License holders expended approximately 1,742 and 1,668 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 40) represented 200,171 kg in 1995/96 and 211,150 kg in 1996/97(or 1.93% and 2.08% of the total catch for the marine scalefish fishery in South Australian waters). Warooka Zone (coastal waters, within 3nm of the coast, from Corny Point to Cape Spencer) – zoned to preserve existing values (ie. conservation) and uses (ie. fisheries, recreation, tourism). Licenses will not be considered for aquaculture development within this zone. Page 139 SPENCER GULF REGION – PONDALOWIE BIOUNIT Tourism Agriculture/Industry − Corny Point: spectacular coastal scenery and a historic lighthouse. − Innes National Park: popular camping area, spectacular coastal scenery and SCUBA diving. Large Blue Gropers and Southern Rock Lobster are particular attractions for SCUBA divers. The small holiday and fishing village of Pondalowie Bay, and South Island are popular camping sites and are excluded from the national park. − Browns Beach: camping area, fishing. − Pondalowie fishing. − SCUBA diving: Corny Point, Browns Beach, Pondalowie Bay, are all recognised reefs dives and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Most of these dives are recommended for experienced divers only. 2.4 − − 2.5 Bay: camping and − Most of the adjacent land in this biounit is predominantly agricultural. Urban Centres − There are no major urban centres, although there are a number of areas with holiday shack development. 2.6 Values Significant Cultural and Historical Aboriginal surfing, − European − The coast from Gleesons Landing to Daly Head has an extensive intertidal and shallow sublittoral platform which is used by schools for teaching purposes. This area was proposed as an educational reserve by the Department of Fisheries in 1974. 26 − `Ethel’: an iron barque of 700 tons that went ashore in January 1904 near Reef Head. Retrieval attempts were unsuccessful, and today one of her boilers can still be seen protruding out of the sand near Reef Head. 3 CURRENT CONSERVATION STATUS OF THE PONDALOWIE BIOUNIT − Marine Reserves None − Marine Parks None − Adjacent Land Use National and Conservation Parks Innes National Park (9,232 ha): includes Royston, Middle and Chinamans Hat islands. Lighthouse at Corny Point. Shipwrecks Scientific Research and Education Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn, Abalone and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Not known. − Netting Closures Brown's Beach (all waters adjacent to Brown's Beach within 1/4 mile of high water mark). Pondalowie Bay (waters contained within a line from Roysten Head through the North, Middle and South Islets to southern shore of Pondalowie Bay). 26 From Yorke Coast Protection District Study Report (Wynne 1980). Page 140 SPENCER GULF REGION – PONDALOWIE BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE PONDALOWIE BIOUNIT Corny Point − Prime IUCN Conservation Values: social values, biodiversity, cultural values (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, geological monuments-Corny Point), ecological (range of marine habitats, seagrass meadows, reef), economic (abalone, rock lobster, marine scale fisheries, tourism), social (shipwrecks, recreation, diving, Corny Point lighthouse), scientific (abalone, rock lobster, marine scalefish research and monitoring), national (potential for Register of the National Estate), practicality (insulation, accessibility, compatibility-adjacent to lighthouse reserve). Formby Bay-Innes National Park27 − Prime IUCN Conservation Values: biodiversity, education, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to humaninduced change), biogeographic (representative marine habitats, geological monuments-Browns Beach), ecological (diversity of marine habitats, high marine biodiversity, reef fish populations Blue Groper, breeding populations-Little Penguins, Silver Gulls, seabirds-Black-faced Cormorants, Pied Cormorant, Reef Heron, Pied Oyster Catcher, Sooty Oyster Catcher, Grey Plover, Hooded Dotterel, Red Neck Stint, Black Winged Stint, Pacific Gull, Caspian Tern, Crested Tern, Silver Gull, Shy Albatross, Little Pied Cormorant, Banded Plover, Banded Stilt, Little Tern), economic (tourism, Greenlip Abalone, Southern Rock Lobster, marine scalefish fisheries), social (`Ethel' shipwreck, recreation, diving, education-Gleesons Landing-Daly Head), national significance (potential for listing on Register of National Estate), practicality (insulation, accessibility, compatibility-adjacent to Innes National Park). 27 Gleesons Landing to Daly Head was nominated for establishment as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, for educational purposes (Wynne 1980). Page 141 SPENCER GULF REGION – GAMBIER BIOUNIT XVIII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE GAMBIER BIOUNIT This biounit comprises the Gambier Isles and Neptune Islands. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This region forms the southwestern arm of Spencer Gulf and has an overall easterly orientation. Consequently, it is a zone of low wave energy with prevailing offshore winds. 2 GEOLOGY AND GEOMORPHOLOGY COASTAL The Gambier Islands include Wedge Island, North Island and several rocky islets and reefs. All are crystalline basement. Wedge Island has a thick "wedge shaped" cover of calcareous aeolianite. The outcrop of crystalline basement is continuous except along the east coast where beach sands have been deposited. Young beach sands have been blown inland on all but the eastern side of the island, and are now covered by sparse vegetation. In the northern portion of the island small lakes occur separated from the ocean by older coastal dunes. North Island has only a thin cover of aeolianite which is substantially covered by recent sand dunes. 3 • The moderate-water areas of North Island are dominated mainly by mixed Cystophora species, such as C. moniliformis, C. siliquosa and C. retorta, in the shallows (5m), whilst seagrass species dominate deeper sites (see below). • − Seagrass species are not dominant at most depths around Wedge Island, although Posidonia and Heterozostera species are common at 10m. Posidonia is dominant at 10-15m around North Island. − Gambier Islands (North Island, South West Rocks and Peaked Rocks and Wedge Island). − Neptune Islands (South Neptunes, North Neptunes). Rocky shore, sandy beaches, intertidal sand flats, subtidal rocky reefs and boulders, seagrass meadows and algae assemblages. MARINE CONSERVATION VALUES Major Benthic Communities 1 Macroalgal 1.1 − Seagrasses Coastal and Offshore Islands (or Reefs) BIOLOGY Major Inshore Habitats − Sheltered shallow-water (5m) areas around Wedge are dominated by the Cystophora species C. subfarcinata and C. moniliformis, and Sargassum species S. fallax and S. spinuligerum. Xiphophora and Osmundaria are also found here, as are various Caulerpa species. Ecklonia and mixed Cystophora (C. siliquosa, C. retorta) and Sargassum (S. fallax, S. verruculosum) species are the algal dominants of waters 10 to 15m deep. Areas of moderate water movement around Wedge Island are dominated by Ecklonia, Scytothalia, Seirococcus and Sargassum fallax at 10 to 20m. Small brown algal species such as Homeostrichus and Chlanidophora are also common. Red algal dominants include Phacelocarpus and Plocamium species. − SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Neptune Islands Conservation Park. The park consists of all islands in the North and South Neptunes with the exception of the southernmost island, which is one of South Australia's last few manned Lighthouse Reserves. The Neptune Islands are of national significance, containing the largest breeding colonies of Page 142 SPENCER GULF REGION – GAMBIER BIOUNIT New Zealand Fur Seal (Arctocephalus forsteri) in South Australia (and Australia). Together, colonies on the Neptune Islands have been recently estimated at almost 16 800 individuals, or 61% of the total SA population (27,616) or 49% of the Australian population (34,700) (Shaughnessy et al. 1994). Breeding colonies of fur seals have been recorded on South Neptune (1,974 pups, estimated population 9,673) and North Neptune (1,472 pups, estimated population 7,212). Haul out and basking sites have been recorded on South Neptune Island (South), Low Rocks (Shaughnessy et al. 1994). − − Colonies of the rare Australian Sea Lions (Neophoca cinerea) have also been recorded on the Neptune Islands. Breeding colonies occur on South Neptune Island (North) (4 pups, estimated population 19), while breeding possibly occurs on Rocky Island (North and South), East Neptune Islands (Gales 1990). Haul out and basking sites in this region include Low Rocks, West Neptune and North and South Neptune Islands (Watts & Ling 1985, Gales et al. 1994). More recently, the Neptune Islands is becoming well-known, both nationally and internationally as one of the major sites in the world for research and filming of White Sharks (Carcharodon carcharias). Grasslands on the islands support 2-4 breeding pairs of Cape Barren Geese annually in the winter months (Robinson et al. 1982) while the whole island supports dense populations of the Southern Bush Rat (Rattus fuscipes). The islands also have significant breeding colonies of seabirds. The `vulnerable' Fairy Terns breeds on South Neptune Island and the Islet of North Neptunes; Crested Terns breed on Lighthouse Island, South Neptune; and Caspian Terns breed on South Neptune Islands (Copley 1996). − Gambier Islands Conservation Park. North Island and Peaked Rock are known breeding sites for rare Australian Sea Lions, while South West Rock is possibly a haul out site only (Gales 1990). New Zealand Fur Seals have been recorded on Wedge Island, Peaked Rock (West), North Island and South West Rock (Shaughnessy 1990). However these sites are not known breeding areas. The open habitat of North Island supports an extremely large population of Southern Bush Rats and these formed part of a recent genetic analysis of island populations of these species (Schmitt 1978; Schmitt & White 1979). − Breeding colonies of Little Penguins, Whitefaced Storm Petrels, common on Wedge Island (Copley 1996). 1.2 − 2 Physical None. OTHER VALUES 2.1 Commercial Fisheries Southern Rock Lobster The offshore islands in this region (Gambier Islands, Neptune Islands, and Thistle Island), and also, north western Kangaroo Island, represent a major region for lobster production in South Australia. In 1995/96 and 1996/97, a total of 51 and 47 licensed operators fished in the area (ie. Fishing Zone 39), catching approximately 108,867 and 136,826 kg of lobsters, respectively (or 2.13% and 2.68% of the total catch for Southern Rock Lobster in South Australian waters). Abalone Within this region, Greenlip and Blacklip Abalone is harvested at the Neptune Islands and the Gambier Isles. In 1994/95 a total of 7,317 kg of Greenlip was harvested around the Neptune Islands (ie. MapCode 17C), and represented 3.2% of the total Greenlip Western Zone catch (or 1.94% of the total catch for Greenlip in South Australian waters). Blacklip Abalone figures are unavailable due to confidentiality constraints. In the Gambier Isles (ie. MapCode 19F), a total of 7,230 and 6,312 kg was harvested during 1994/95 and 1995/96, which represented 3.2% and 2.8% of the total Greenlip Western Zone catch (or 1.92% and 1.69% of the total catch for Greenlip in South Australian waters). Blacklip Abalone figures are unavailable due to confidentiality constraints Marine Scalefish Fisheries Fishing is limited within the Gambier Islands, Neptune Islands, and Thistle Island (and also, along the north western coast of the Kangaroo Island) (ie. Fishing Zone 39). In 1995/96 and 1996/97, a total of 21 and 31 licensed operators fished in the area (ie. Fishing Zone 39), catching a total of 66,188 and 86,753 kg, respectively (or 0.64% and 0.86% of the total catch for the marine scalefish fishery in South Australian waters). Page 143 SPENCER GULF REGION – GAMBIER BIOUNIT 2.2 Aquaculture Within the Gambier Region, the remoteness of this region and its general exposure to waves and swell suggest that aquaculture development is unlikely, even in the lee of islands. Within the offshore Spencer Gulf region, aquaculture development is unlikely in the near future. While sea cages have now been developed which can withstand the physical forces that might arise in this region during storm conditions, their costs are exceedingly high. This cost factor, the need for automating feed delivery so as to reduce shore based servicing frequency, the present availability of nearer shore sites, and the preliminary nature of finfish culture in South Australia, all suggest that aquaculture development within this region is unlikely in the near future. 2.3 − − 2.4 − − Recreation and Tourism Researchers from the SANPWS regularly conduct surveys of Australian Sea Lion and New Zealand Fur Seal colonies on the islands. Offshore islands: the following areas are popular for SCUBA diving and recreational fishing (including Abalone and Southern Rock Lobster) - Hopkins and Thistle Islands, West Bay, Gambier Islands (Wedge Island), Sir Joseph Banks Group of Islands, and the Althorpe Islands. Access to these islands is through charter companies such as Failie Charters, as well as by private vessels. 2.5 National and Conservation Parks − Gambier Islands Conservation Park (64 ha): comprises three islands and islets of the Gambier Group, North Island, SW Rocks and Peaked Rocks. Wedge Island, the main island of the Gambier Group is held in freehold title and is run as a tourist resort. − Neptune Islands Conservation Park (318 ha): includes all islands in the North and South Neptunes with the exception of the southernmost island which is one of South Australia's last few manned Lighthouse Reserves. − Agriculture/Industry None. − Urban Centres None. 2.6 Features − Other research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Western King Prawn and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. Significant Cultural and Historical Aboriginal Not known. European Shipwrecks − `Glenpark' (1897-1901): a Historic Relic declared under the South Australian Historic Shipwrecks Act 1981 (the only one in South Australia). The vessel, a three-masted steel ship, ran ashore on a rock off Wedge Island. 3 CURRENT CONSERVATION STATUS OF THE GAMBIER BIOUNIT Scientific Research and Education Gambier Islands Conservation Park: the open habitat of North Island supports an extremely large population of Southern Bush Rats and these formed part of a genetic analysis of island populations of these species (Schmitt 1978; Schmitt & White 1979). Adjacent Land Use − Marine Reserves None − Marine Parks None − Netting Closures Wedge Island (all waters between Wedge Island and North Islet contained by two lines; one from the western point of Wedge Island to the western point of North Islet and the other from the eastern tips of both islands). Page 144 SPENCER GULF REGION – GAMBIER BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE GAMBIER BIOUNIT Gambier Isles − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative habitats, unique geology), ecological (range of habitats, nursery areas, breeding areas for rare Australian Sea Lions, haul out sites for New Zealand Fur Seals, breeding colonies of Little Penguins, White-faced Storm Petrels), economic (abalone, rock lobster, marine scale fisheries, dive tourism and fishing charters), social (historic shipwrecks-`Glenpark’, recreation, education), scientific (marine mammals, abalone, rock lobster research and monitoring), national (potential for Register of the National Estate), practicality (insulation, compatibility-adjacent to Gambier Isles Conservation Park). Neptune Isles − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness(not subjected to human-induced change), biogeographic (representative habitats, largest breeding colonies of New Zealand Fur Seals in Australia, unique geology), ecological (range of habitats, nursery areas, breeding areas for New Zealand Fur Seals, haul out sites for Australian Sea Lions, breeding sites for seabirds-`vulnerable' Fairy Terns, Crested Terns, Caspian Terns, White Shark populations, roosting sites for Cape Barren Geese, Southern Bush Rat), economic (Blacklip Abalone, Southern Rock Lobster, marine scale fisheries, tourism), social (education), scientific (monitoring and research sites for New Zealand Fur Seals, White Shark populations, abalone, rock lobster research and monitoring), national (Register of the National Estate, national importance of breeding colonies of New Zealand Fur Seals), practicality (insulation, compatibility-adjacent to Neptune Islands Conservation Park). Page 145 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF GULF ST VINCENT - FLEURIEU PENINSULA REGION MARINE BIOGEOGRAPHY 1 2. 3. 4. 5. Gulf St Vincent – Fleurieu Peninsula Oceanography Climate Coastal Geomorphology and Landforms Biology MARINE CONSERVATION VALUES 1. 2. 3. Significant Biological and Physical Features Significant Cultural or Historical Features Current Conservation Status of Gulf St Vincent BIOUNITS 1. 2. 3. 4. 5. 6. Sturt Investigator Orontes Clinton Yankalilla Encounter Page 146 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF GULF ST VINCENT - FLEURIEU PENINSULA REGION MARINE BIOGEOGRAPHY 1 GULF ST VINCENT – FLEURIEU PENINSULA Gulf St Vincent falls within the coastal geomorphological region known as the Gulfs Province (Short et al. 1986). This region extends from Cape Catastrophe, on the south eastern tip of Eyre Peninsula, to Rapid Head on the Fleurieu Peninsula, and includes South Australia's other large sheltered gulf ecosystem; Gulf St Vincent. Within these sheltered gulf waters occur some of the largest temperate seagrass ecosystems in the world. The sheltered waters also provide an ideal habitat for extensive, intertidal forests of the Grey Mangrove, most of which occur in this region. Together, these coastal ecosystems are of immense ecological and economic importance, providing the essential basis for much of South Australia's commercial and recreational fisheries. The coastal areas of the gulfs however, also support the major urban and industrial cities of South Australia. Historically, this province is also of the greatest maritime significance, reflecting essentially the early European settlement of this region. However, present and future urban and industrial activity in this province, also places this region under the greatest threat from human activity. The Fleurieu Peninsula, from Rapid Head to the Murray Mouth falls within the broad coastal geomorphological region known as the Coorong Province, which is dominated by the large, beach dune barrier lagoon complex known as the Coorong Lagoon. 1.1 Biogeography of Gulf St Vincent - Fleurieu Peninsula Within the Flindersian Province, the Gulf St Vincent ecosystem encompasses a well-defined biogeographical region known as the Gulf St Vincent Bioregion, which extends from West Cape to Cape Borda (Kangaroo Island), and from Cape Jervis to Cape Willoughby (IMCRA 1997). However, the southern coast of the Fleurieu Peninsula, from Cape Jervis to the mouth of the Murray River, falls within another marine biogeographic known as the Coorong Bioregion, which extends Cape Jervis east to Cape Jaffa, to Cape Borda (Kangaroo Island) (IMCRA 1997). A complete physical and ecological biogeographic description of the Gulf St Vincent Bioregion and also, the Coorong Bioregion, including marine fauna and flora, has been described by IMCRA (1997). Based on coastal geology, wave climate, and coastal orientation, Short and Fotheringham (1986), identified six coastal geomorphological regions (or subprovinces) for the Kangaroo Island coast: 1 2 3 4 5 6 Southern Yorke Peninsula Subprovince Central Gulf St Vincent Subprovince Northern Gulf St Vincent Subprovince Adelaide Metropolitan Subprovince Rapid Bay Subprovince Encounter Bay Subprovince Based on patterns of biogeography and marine habitats (and also, existing coastal geomorphological classifications), a total of 6 marine biounits have been recognised for the Gulf St Vincent – Fleurieu Peninsula region: 1. 2. 3. 4. 5. 6. Sturt Biounit Investigator Biounit Orontes Biounit Clinton Biounit Yankalilla Biounit Encounter Biounit – Along the southern coast of Australia, marine biogeographers recognise a major biogeographic region, known as the Flindersian Province, which extends from south-west Western Australia to southern New South Wales and includes the waters of Victoria and Tasmania. Within this broad region, the coastal waters of the Great Australian Bight (west of Robe) are recognised as warm to cool temperate (in contrast to the cold temperate waters of the south-east of Australia, east of Robe). Page 147 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS 2 2.1 OCEANOGRAPHY Wave Climate Wave energy in the Gulfs Province ranges from moderate at the mouths of both, Spencer Gulf and Gulf St Vincent, to very low in the upper regions. Overall, the gulfs are very sheltered ecosystems, subject to very low to low wave energy regimes. In Gulf St Vincent, tides are also semi-diurnal but there is a marked difference in their tidal amplitudes throughout the gulf. The tidal range varies from a minimum of approximately 1 m (spring low water to spring high water) at the south western tip of Yorke Peninsula, through approximately 2 m in the lower and mid gulf waters, to 3 to 3.5 m at the head of the gulfs (de Silva Samarasinghe & Lennon 1987). Storm surges of up to 1 m are also possible due to the effects of strong winds. These effects become more pronounced in the upper gulf waters due to a `funnelling effect'. Backstairs Passage is subject to strong tidal races, and water movement through the passage is influenced throughout much of the year by the anti-cyclonic circulation of the Myponga Eddy, adjacent to the southern Fleurieu Peninsula (Bye 1976). In both gulfs, a regular period of minimal tidal movement occurs, called a `dodge tide' (Gostin et al. 1984). 2.2 Water Temperature and Salinity Both Spencer Gulf and to a lesser extent, Gulf St Vincent, are basically hypersaline-high water temperature ecosystems. They are also referred to as `reverse estuaries', because waters of highest salinities and temperatures occur at the `head' or upper reaches of the gulfs, rather than near the open ocean (de Silva Samarasinghe & Lennon 1987). Seasonal surface water temperatures vary from 12°C to 25.9, while salinities vary from 35.5 ppt to 42.0 ppt (de Silva Samarasinghe & Lennon 1987). The cooler waters off the southern Fleurieu Peninsula, are more typical of the Coorong Bioregion (ie. mean sea surface temperatures varying from 14°C in winter to 18°C in summer). The salinity of the waters in Encounter Bay and Backstairs Passage is also relatively uniform (ie. 35.5 ppt to 36 ppt). 2.3 Currents In Gulf St Vincent, the coastal water currents are predominantly in a clockwise direction, affecting the Yorke Peninsula coast (Bye 1976). Waveinduced littoral currents move in a northerly direction, affecting both the Yorke and Fleurieu Peninsula coasts. Along the southern coast of Yorke Peninsula, tidal and littoral currents move in a predominantly easterly direction. On the west coast of the Yorke Peninsula, littoral currents move predominantly north. In both gulfs, the major tidal currents carry fine, suspended sediment which settle out in the upper reaches, effectively creating very large sedimentary basins. The main process modifying the eastern Yorke Peninsula coast appears to be windwaves rather than currents. Exceptions to this occur at only a few locations, such as at Sultana Point where the presence of the Troubridge Shoal causes strong tidal currents across shallow, mobile sandpits. However, even here, the main erosional force is still windwaves. The bottom of Investigator Strait is swept by strong tidal currents of 50-200 cm/sec; currents are weakest near the coast of Yorke Peninsula and Kangaroo Island and increase with increasing distance from shore, becoming strongest in the middle of the Strait (Shepherd & Sprigg 1976). 3 CLIMATE The climate of the Gulfs Province is typically semiarid or `Mediterranean' and as such, is characterised by hot, dry summers and cool, moist winters. It is largely influenced by mid-latitude anticyclones or high pressure systems which pass from west to east across the continent. Winter generally brings southerly to southeasterly winds and low pressure systems which travel across the Southern Ocean between 40 and 50oS, bringing frontal activity and rain. Summer brings northerly to northwesterly winds. The gulfs themselves have an ameliorating effect on the coastal regions, producing more temperate weather. The prevailing wind patterns are also influenced by the gulfs. Page 148 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Most rainfall falls during winter, however it varies considerably with latitude, from approximately 500 mm in the south to less than 300 mm in the north. The climate of the Fleurieu Peninsula, particularly the south coast, is typically mesothermal or `cool temperate’, with a distinct winter-spring maximum, cool winters and warm, dry summers. 4 COASTAL GEOMORPHOLOGY LANDFORMS AND Coastal Geology Gulf St Vincent, like Spencer Gulf, is a large, semiarid, tidal plain coast, characterised by sedimentary processes, and an almost complete lack of significant quantities terrestrial and fluvial erosional inputs into the gulf waters. Consolidated Cambrian and Precambrian rocks form most of the rocky cliffs that line the southerly and south-easterly margins of Gulf St Vincent and approaches, and also, the western gulf region, south of Ardrossan on Yorke Peninsula. Most of the remainder of the coast of the gulf comprises soft, sandy and clayey outwash sediments of Permian, Tertiary of Quaternary age (Shepherd & Sprigg 1976). Tertiary uplift, and former interglacial high sea-levels, have left a succession of stranded cliffs, raised shore platforms, and prominent erosional points, around most of the coastline from the western extreme of Kangaroo Island, via Cape Jervis, to Marino near Adelaide. Along this coast, boulder and cobble littoral beach deposits occur submerged (eg. Yankalilla Bay, Hallet Cove south), at, or above, modern beach level at the bases of many of the cliffs. The most southern of the Glenelg relict ,sand-covered, submerged shorelines overlie ancient mangrove swamps with heavy roots still in situ. Tertiary limestone sediments form submerged marine outcrops off Ochre Point, Willunga, Christies Beach (ie. Horseshoe Reef) and off Noarlunga, however the linear offshore Port Noarlunga reef is probably a remnant of a consolidated river deposit (and not a marine deposit). Submarine basement rock outcrops are rare in the gulf, other than granite pedestals at the western entrance to Investigator Strait, and a submerged reef (of Proterozoic origin) south west of Normanville (Shepherd & Sprigg 1976). Permian shales also outcrop in the 71m deep channel of Backstairs Passage. Consolidated and calcrete cemented shell beds floor much of Investigator Strait and extend onto the Orontes Shelf (Shepherd & Sprigg 1976). In Investigator Strait, extensive areas of this broad, low profile platform reef carry a thin veneer of coarse shelly sand (and where undermined, forms ideal habitat and shelter for the Southern Rock Lobster). Along the north coast of Kangaroo Island, particularly north of Snug Cove, and over much of Eastern Cove (Nepean Bay), consolidated calcareous sand (ie. aeolianite) dunes form prominent sea floor eminences and rough bottom topography, which support a rich diversity of marine life (including algae, sponges, crinoids, reef-molluscs, lobster, and fish populations). Along the 10-20 km wide Orontes Shelf, particularly east of Troubridge Island, the calcreted Pleistocene shell bed forms extensive flat rocky surfaces, or low erosional escarpments (5m or more high). Once again, these provide excellent habitat for a diversity of marine life. Between Troubridge Island and Sultana Point, an array of tidally exposed reefs represent remnants of consolidated Quaternary sand dunes. Sand bars or “spits”, caused by strong tidal currents (and which extend up to 2-4 km offshore, in a northeast direction), are a dominant feature of the east and south coast of Yorke Peninsula (eg. Stansbury, Port Vincent, Sheoak Flat and Black Point), and represent extensions of stranded Quaternary beach deposits. Coastal Geomorphology In contrast to Spencer Gulf, the coast of Gulf St Vincent is relatively free of coastal embayments (with the exception of Salt Creek Bay, near Edithburgh). Towards the top end of the Gulf waters are shallow, and the low coast is backed by mangrove forests and there are no rock outcrops. At Ardrossan, a cliff has been excavated in soft sands and clays, but these cliffs rapidly diminish in height both, north and south of the town. South of Rogue Point, the cliffs begin again and from Port Julia to south of Wool Bay there is an almost unbroken cliff line between 6-18 metres high, cut in horizontally layered sandstone and limestone. Page 149 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS There is evidence along the east coast that erosion is at a minimum at the present time and the dominant factor in the present cycle of coastline evolution is deposition, not erosion. Sand is being transported by currents along the shore longshore drift. The triangular forelands on which Stansbury and Port Vincent are built, indicate that sand is being carried from the south in a northerly direction and beginning to form a ridge or sandspit. Black Point and Sultana Point show similar features although the history of their formation is rather more complex. In many places shell beds and typical sandy beach deposits are found well above present day high water mark, indicating a period when sea level was higher than it is today. On the east coast, such raised beaches are found at Parara Point and Ardrossan, whilst on the west coast a well marked raised beach is found at Point Brown. The west coast of Yorke Peninsula is more irregular than the east, and consequently a few more bays have developed at Moonta Bay, Port Victoria and Hardwicke Bay. Cliffs are not common, although resistant headlands composed of hard granitic rocks do occur at Port Gawler, Pearce Point and along the west coast of Wardang Island. A series of beach dune ridges built up during former high still stands of the sea are particularly well developed east of Point Turton and also near Port Victoria and Cape Elizabeth. There are even more extensive ridges on the northern coast of the foot. The coasts along the `foot' of Yorke Peninsula show strong evidence that vigorous erosion is occurring, due primarily to strong prevailing winds and associated storm waves coming from the Southern Ocean. The influence of bedrock on landscape development can be clearly seen, and all the prominent headlands are formed of hard resistant granitic rocks eg. Corny Point, Daly Head and Point Yorke. South of the Fleurieu Peninsula (and Kangaroo Island), the flow of the Murray River has resulted in the formation of deep and extensive submarine Murray Canyons which transect the continental shelf down to the abyssal plains (von der Borch 1979). Shallow sections of these extremely deep (ie. 4,600 metres) canyons occur in Backstairs Passage and south of Encounter Bay and the Murray Mouth. 5 Biology 5.1 General Ecology A diverse range of major habitats are represented within Gulf St Vincent. These include: mangrove forest and their associated samphire and mudflat habitats; rocky reefs; sandy beaches; estuaries; subtidal reefs; seagrass meadows and bottom fauna. It is possible to summarise the major assemblages and communities present according to the wave regime experienced in the area. This is by no means definitive, however, as local variations will occur. The more sheltered conditions in Gulf St Vincent allow extensive stands of mangrove forests, together with their associated tidal mud flats and samphire communities. The general marine intertidal biology of the Gulf St Vincent has been summarised by Womersley & Edmonds (1958), and more recently by Womersley (1990). On coasts of moderate wave energy within Gulf St Vincent Bioregion (ie. southern coasts of Gulf St Vincent), the intertidal and sublittoral fringe of rocky shores are dominated by the brown algae: Hormosira banksii and Cystophora sp. On rocky coasts with some wave action, the upper sublittoral zone is dominated by larger brown algae, especially Ecklonia radiata, Cystophora subfarcinata, C.retorta, C.polycystidea, C.moniliformis and other species, Caulocystis cephalornithos, Cystophyllum onustum and Sargassum spp. (such as S.decipiens, S.lacerifolium), with an understorey of coralline algae (for eg. Amphiroa anceps, Cheilosporum elegans), Cladostephus spongiosus and often species of Caulerpa. On sandy bottom below rocky areas the seagrasses, Amphibolis and Posidonia often cover very extensive areas as dense, often pure, communities. On coasts of slight wave action, with sandy or muddy flats or beaches (eg. northern parts of Gulf St Vincent, excluding rocky outcrops, and reverse estuaries ie. Barker Inlet), the intertidal and sublittoral fringe is dominated by samphires, the Grey Mangrove, Avicennia marina, Hormosira banksii, Pinna bicolor and the algae Hypnea, and Spyridia in the sublittoral fringe. According to von der Borch (1979), the canyons are probably an important source of nutrient upwelling, contributing to the significant coastal productivity in the region. Page 150 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS 5.2 Subtidal Ecology Gulf St Vincent has a wide variety of subtidal benthic habitats. These habitats range from the deep water invertebrate-dominated benthic environments of the central gulf and Backstairs Passage, to the extensive seagrass meadows (and intertidal mangrove and saltmarsh communities) of the northern Gulf, and the extensive seagrass-reef shoal system of the Orontes Bank, to the algaldominated platform reefs scattered throughout Investigator Strait and the south-eastern region of the gulf (ie. metropolitan and Fleurieu coast). Reefs in southern Gulf St Vincent, such as the “heel” of Yorke Peninsula and Backstairs Passage, also experience strong tidal currents, and support great abundance and diversity of reef floral species (Edyvane and Baker 1996). Sandy areas (colonised by seagrass), like Spencer Gulf, dominate much of northern reaches of the gulf and also include large southern embayments (ie. Yankalilla Bay and Nepean Bay). Seagrasses in Gulf St Vincent cover a total area of 2436 km2 , which represents approximately 25% of the total area of seagrass recorded in South Australia. Seagrass meadows in Gulf St Vincent and Investigator Strait, like Spencer Gulf, act as key “carbonate factories”, trapping and also providing the carbonate basis for sediments in the gulf, ie. from the destruction of molluscs in shallower, wave-agitated waters, and bryozoa, calcareous algae and foraminifera in deeper waters (Shepherd & Sprigg 1976),. The subtidal ecology of Gulf St Vincent, Backstairs Passage and Investigator Strait has been detailed at length by Shepherd and Sprigg (1976). Algal communities are prominent on the subtidal cliffs and rocky shores bordering lower Gulf St Vincent and Investigator Strait, from low water mark to a depth of 5-15m (according to locality), until the rock becomes buried by sand. As in other parts of South Australia, the nature of the algal vegetation on subtidal rocky reefs varies significantly with wave exposure, depth and substrate geology. Three depth-related zones are recognised on rocky reefs: 1. Upper Sublittoral Zone (3-5m) – algal turf zone - dominated by Cystophora intermedia, Megabalanus barnacles and short, dense turfing coralline algae (Haliptilon, Corallina), and Pterocladia capillacea under (low wave energy conditions). 2. 3. Mid Sublittoral Zone (5-15m) – large brown algae, canopy-forming zone - dominated by Ecklonia radiata and other large brown algae (species of Cystophora and Sargassum) and also, Melanthalia. Lower Sublittoral Zone (17-29m) – mixed-red algal zone – dominated by a dense cover of red algae, including species of Plocamium, and other small delicate species. Similarly, algal vegetation also varies significantly with wave exposure. As in other areas of South Australia, macroalgal species are commonly replaced by better adapted species as wave exposure and water movement varies. This is particularly the case in the genera Cystophora and Sargassum, which show a `replacement series’ along a wave exposure gradient. Under conditions of high wave exposure, rocky reefs are typically dominated by large brown algae (30-100cm in height), such as Scytothalia dorycarpa, Ecklonia radiata, Seirococcus axillaris and species of Sargassum (S.bracteolosum, S.lacerifolium, S.varians, S.distichum, S.linearifolium), Cystophora (C.moniliformis) and species of Myriodesma (M.quercifolium, M.integrifolium). Under moderate wave conditions, reefs are commonly colonised by species of Cystophora (C.retorta, C.subfarcinata, C.monilifera) and Sargassum (S.sonderi, S.paradoxum, S.biforme) and Sporochnus comosus, Caulocysis uvifera, and Encyothalia cliftoni. Under conditions of low wave energy, reefs are dominated by species of Cystophora botryocystis, C.polycystidea) and species of Sargassum (S.decipiens, S.spinuligerum, S.halitrichum) and Scaberia agardhii. Common grazing animals in algal communities on rocky reefs include sea urchins (Heliocidaris erthrogramma, Phllacanthus parvispinus and Goniocidaris tubaria), abalone (Haliotis laevigata, H.ruber, H.scalaris) and the gastropod, Subninella undulata (Shepherd & Sprigg 1976). The distribution of bottom dwelling animals within Gulf St Vincent is influenced by substrate type, depth, light and hydrological conditions. A total of 6 distinct animal assemblages have been identified by Shepherd and Sprigg (1976) within Gulf St Vincent and Investigator Strait: (1) Pinna-holothurian assemblage – dominant in the muddy, silty substrates of the upper reaches of the gulf. The community is characterised by the razorfish, Pinna bicolor, which supports a rich epizoic assemblage of small sponges, ascidians and bryozoans. The “milk bottom ascidian”, Phallusia, is also common. Page 151 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS (2) ascidian-scallop assemblage – dominant in depth of 15-30m, under conditions of low to moderate water current. Ascidians commonly occur (attached to shell fragments), together with scallops and other bivalves, and their predators, the seastars, Coscinasterias and Luida are common. Red algae and the seagrass, Halophila ovalis , are also common. (3) bryozoan assemblage – dominant in the deepest reaches of the gulf. The community is characterised by large, erect bryozoans (such as the “basket” bryozoan, Adeona grisea and others), and massive sponges. Ophiuroids and crinoids are commonly epizoic on the bryozoans and sponges. (4) Malleus/Pinna assemblage – dominant in the lower eastern part of the gulf, around Rapid Bay, where the water depths are greatest and the water current is slightest. The silty muddy bottom is characterised by the hammer oyster, Malleus meridianus, the razorfish, Pinna bicolor and the scallop, Pecten meridionalis, and small sponges and erect bryozoans. (5) Heterozostera/Lunulites assemblage – dominant in the sandy, strong tidal flow areas of Investigator Strait, at depths of 25-35m. Areas are colonised by sparse Heterozostera tasmanica, a sparse animal species. Fauna is limited to the “button bryozoan” Lunulites and the brachiopod, Magadena cumingi, both of which lie on the surface of the sand, and species such the seapen, Sarcophyllum grande, stalked fan bryozoan, Parmularia, and the stalked ascidians, Pyura australis and P.spinifera, which can secure anchorage on the unstable bottom. Towards the Kangaroo Island side of Investigator Strait, on rocky reefs, massive erect, orange sponges occur everywhere, together with large populations of its predator, the black and white psolid holothurian, Ceto cuvieri. (6) sponge/bryozoan assemblage – dominant in the deep (>50m), tidal race of Backstair Passage. This community is characterised by massive sponges (more than 1 metre high and across) and large erect bryozoans (such as Adeona grisea); epizoic crinoids and ophiuroids are especially abundant on them. 5.3 Seagrass Ecology Seagrasses (particularly Posidonia australis and Amphibolis antarctica), as in Spencer Gulf, are important in trapping and stabilising the sediments of the Gulf St Vincent. The seagrass leaves baffle action and reduce water movement to such an extent that fine suspended particles settle out, and are trapped by the root mesh of the seagrass (Shepherd & Sprigg 1976). The sediments of these seagrass banks consist largely of carbonate skeletal debris from epiphytic coralline algae, bryozoans, molluscs and foraminifera, together with aggregates of aragonite and quartz grains. These banks have been studied in detail in upper Gulf St Vincent, where they have been shown to have caused the shoreline to migrate seaward several kilometres since sea level stabilised at is present level approximately 6 000 years ago. Seagrass beds are well developed in Gulf St Vincent colonising sandy-muddy areas of tidal flats, and extending several metres deep. Eight species of seagrass occur subtidally in the gulf region (Shepherd & Sprigg). Four of them, Amphibolis antarctica, Posidonia australis, Heterozostera tasmanica and Halophila ovalis occur over extensive areas of sandy seafloor. Amphibolis antarctica and Posidonia australis occur as dense monospecific meadows stands, while Heterozostera tasmanica and Halophila ovalis occur as scattered plants or clumps of plants, especially in deeper water. In addition there are two other species which are less common: Posidonia ostenfeldii which occurs in scattered stands on the north coast of Kangaroo Island, and the eastern shore of the gulf, and Amphibolis griffithsii, which usually occurs as meadows at depths of 10-15m, and also as isolated plants among stands of A.antarctica (Shepherd & Sprigg 1976). Posidonia australis is the most extensive community of seagrass in the Gulf St Vincent region, preferring shallow waters, but extending down to 30m in Investigator Strait, 20m in the lower gulf and 10m near the head of the gulf (Shepherd & Sprigg 1976). The meadows on the western side of the gulf are usually less dense than on the eastern side. P.australis grows sympatrically with P.sinuosa and P.angustifolia in the shallower part of their range. Amphibolis antarctica is better adapted than Posidonia to stronger water movement and mobile sandy substrates, and generally occurs in small stands or clumps rather than as extensive meadows characeristic of Posidonia. A.antarctica occurs from the uppermost sublittoral zone to 23m, but in the gulf rarely occurs in depths exceeding about 12m. A.antarctica commonly occurs on sand spits and bars and is an earlier coloniser in denuded areas in Posidonia australis meadows, often bordering the shallow or shoreward side of a Posidonia meadow. The species also occurs in sandy areas where underlying rock prevents the establishment of a Posidonia meadow, or in mixed stands with Posidonia, under conditions of moderate water movement. Page 152 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Heterozostera tasmanica is widely but sparsely distributed in the gulf, and occurs on firm muddy substrates from low tide level down for 35 m (Shepherd & Sprigg 1976). Halophila ovalis, like Heterozostera tasmanica, is also widespread but sparse in the gulf (particularly in the deeper waters), and occurs in areas of slight to moderate water current, from 5-35m depth. P.sinuosa is widely distributed to a depth of 15m in sheltered bays and inlets, either in pure stands or growing sympatrically with P.australis or P.angustifolia. In more exposed areas it may form meadows with Amphibolis spp. P.angustifolia grows subtidally from 2-35 m deep and frequently grows in deeper water than P.australis. In it's deeper range it is often found in association with Heterozostera tasmanica or Halophila australis and in sheltered positions in it's shallower range in association with Amphibolis antarctica. Other seagrasses of note in Gulf St Vincent include: Halophila australis which grows on sand and mud, from low tide level to 23m deep; Ruppia spp. (R. tuberosa); Lepilaena marina which forms extensive low turfs in mid and lower eulittoral zones on sandy mud tidal flats, often growing in association with Ruppia tuberosa and Zostera mucronata; and Amphibolis griffithii which forms pure stands or mixed communities with A. antarctica from low tide to depth of 5m. A.griffithii generally extends into rougher localities and tolerates lower light intensities than A.antarctica. 5.4 Fish The marine fish fauna found in the oceanic waters off Yorke Peninsula and Fleurieu Peninsula is typical of the Flindersian Province of southern Australian coastal waters (Glover & Olsen 1985). As such, many of the species recorded in South Australian waters, have also been recorded in southern and south-western Western Australian waters, and to a lesser extent, in the waters of western Victoria and north-west Tasmania. There are some 300 species of known marine fish recorded off Eyre Peninsula down to the base of the continental slope, which represents approximately 67% of the species recorded from all South Australian marine waters (Glover 1982). The fish fauna of Gulf St Vincent, as with Spencer Gulf, is typical of the Flindersian Province of southern Australian coastal waters (Glover & Ling 1976). As such, a total of 216 species have been recorded from Gulf St Vincent, representing 113 families and 33 orders of fish, including a handful of sporadic oceanic strays such as Sunfish (Mola sp.). However, Gulf St Vincent's waters constitute the type locality for 26 recognised species, 7 of which appear to be endemic. All are essentially marine, except a few species which are known to spend a least part of their life cycles in the more dilute waters of estuaries, and further upstream in waterways entering the sea. These latter species include the Short-Headed Lamprey (Mordacia mordaxz) and the native Trout (Galaxias maulatus). Although the variety of fish in Gulf St Vincent is relatively small, compared with warmer Australian waters, there is an abundance of economically important species. As such, some 14 principal species are fished in the gulf (Glover & Ling 1976). The waters of Gulf St Vincent, like Spencer Gulf are among some of the most commercially productive in the South Australia. As such, the most valuable single species fishery in Spencer Gulf, is the Western King Prawn (Penaeus latisulcatus). The marine recreational fishery in Gulf St Vincent is renowned for the variety of species which provide abundant and excellent sport for line, spear and big-game fishers. 5.5 Marine Mammals In Gulf St Vincent, although there are no major colonies of seals or herds of whales, individuals of many species are regularly seen in these waters and on local beaches. The Australian Sea Lion (Neophoca cinerea), and the New Zealand Fur Seal (Arctocephalus forsteri), haul out on islands in Investigator Strait (ie. Althorpe Island, Little Althorpe Island, Seal Island, Haystack Island) and the north coast of Kangaroo Island, and occasionally on Adelaide beaches occasionally. Sightings are also regularly made at various places around the coast of the Fleurieu Peninsula (eg. Encounter Bay). New Zealand Fur Seals have regularly visited West Island (Victor Harbor) over the last 5 years however there is presently no evidence of breeding (S.Shepherd, pers.comm.). There are also occasional sightings of Leopard (Hydrurga leptonyx) and Weddell Seals (Leptonychotes weddelli). Some 18 species of whales have been recorded in South Australian coastal waters (Aitken 1971). Pilot Whales (Globicephala melaena) enter Gulf St Vincent occasionally and have gone aground on local beaches. The largest recorded mass stranding of whales occurred in 1944 when almost 300 False Killer Whales (Pseudorca crassidens) went aground at Port Prime in Gulf St Vincent (Glover & Ling 1976). Several species of whales frequent the waters around Kangaroo Island and Encounter Bay, and strandings also occur occasionally. In particular, the endangered Southern Right Whale (Eubalaena australis) appears regularly in the winter months during its northward migration from Tasmanian Page 153 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS waters to the waters at the Head of the Great Australian Bight. Along Encounter Bay in particular, the whales can be easily from shore. The Bottlenose Dolphin (Tursiops truncatus) and the Common Dolphin (Delphinus delphis) are common in both Spencer Gulf and Gulf St Vincent. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Mangrove and Coastal Saltmarshes Gulf St Vincent (along with Spencer Gulf) contains some of the most extensive areas of mangrove forests and tidal wetlands in South Australia (and the largest areas of temperate mangroves in Australia) (Edyvane 1996). Associated with the mangrove habitats are the biologically rich mud flats, coastal saltmarshes and seagrasses. Together, mangrove and saltmarsh communities along the South Australian coast total approximately 82,000 ha, with the largest communities occurring in Spencer Gulf (46 000 ha) and Gulf St Vincent (20,000 ha). Other substantial communities occur in lower Spencer Gulf (6 000ha), on the west coast of Eyre Peninsula (9 000 ha) and on Kangaroo Island (7 000 ha) (DELM 1993). In Gulf St Vincent, mangroves, and associated coastal saltmarshes, seagrasses and tidal mudflats dominate the upper portion of the Gulf from Port Clinton to Port Adelaide. Mangrove forest comprise a single species, the Grey Mangrove, Avicennia marina, which forms a low woodland forest extending from mean sea level to spring high-tide level. Progressively higher vegetated zones are a Halosarcia-Sarcocornia (saltmarsh) association, a Sclerostegia-Halosarcia (saltmarsh) association and an Atriplex (saltbush) association (Chinnock 1980). These tidal wetlands are areas of considerable productivity and represent significant feeding habitats for waterfowl and waders, and also represent key nursery, feeding and breeding areas for many economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Conspicuous algal mats, which form as a result of sediment trapping by filamentous blue-green algae are associated with both, the mangrove and saltmarsh flora. A variety of marine organisms, mostly gastropods, bivalves, polychaetes and crustaceans, also live in and on the mangrove mud, and are a key food source. Extensive Seagrass Meadows Gulf St Vincent (along with Spencer Gulf) contain some of the most extensive areas of temperate seagrass meadows in Australia (Edyvane 1996). These extensive seagrass meadows flourish in the shallow waters of the gulf, generally in waters less than 15m, and provide the basis for the significant productivity of the gulf in terms of fisheries and prawn production. Seagrasses cover approximately 2,436 km2 in Gulf St Vincent, and represent 25% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the northern reaches of the gulf (ie. Clinton Biounit, 132,576 ha), in the Orontes Bank region along the eastern coast of Yorke Peninsula (ie. Orontes Biounit 51,713 ha), and along the southern coast of Yorke Peninsula in Investigator Strait (Sturt Biounit, 23,229 ha). Seagrass meadows are particularly important for a number of reasons: as primary producers they occupy the base of the food chain; they provide important or “critical” habitats such as nursery, breeding or feeding areas for the juveniles and adults of many fish, crustaceans and other marine animals, including a large number of commercial species (Bell & Pollard 1989, Howard et al. 1989); and their extensive root and rhizome systems stabilise nearshore sediments and sand banks, enhancing coastal water clarity and reducing coastal erosion (Scoffin 1971). Seagrass meadows also support a prolific skeletal biota as infauna and epiphytes, which in turn, provides the carbonate basis for sediments in the region. Page 154 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Backstairs Passage The Backstairs Passage region is unparalleled in it’s diversity of marine invertebrate assemblages and is one of the richest areas for sessile invertebrate fauna in South Australia (Dr Scoresby Shepherd, SARDI, pers.comm.). The seafloor of Backstairs Passage has been little studied and generally the water depths (35-70m) and current speeds (up to 250 cm/sec) are too great to allow easy study by diving (Shepherd & Sprigg 1976). Strong current flows in the narrow Passage provide optimal conditions for filter-feeding organisms and many organisms, particularly sponges and bryozoans, reach very large proportions and also, importantly, outcompete plant communities in colonising shallow reefal areas in high current regions. At 40m depth, the substrate consists of a planed-off surface of bedrock covered with a thin layer of sediment made up of coarse sand, small flat pebbles and biogenic carbonates. These sediments form drifts in the lee of the sparse exposed reef outcrops of Permian shales. At greater depths (>50m) in the tide race, massive sponges (more than 1 metre high and across) and large erect bryozoans (such as Adeona grisea), dominate the sea bottom; epizoic crinoids and ophiuroids are especially abundant on them (Shepherd & Sprigg 1976). In the sediment drifts, the brachiopod Magadena cumingi reaches densities up to 80/m2 . The deep water sessile invertebrate fauna of the Passage is of national importance with regard to the diversity of brachiopods (Dr Scoresby Shepherd, SARDI, pers.comm.), and possibly, global importance if records of stalked crinoids by the SA Museum (ie. Dr J Mitchell) are confirmed. The deepwater sponge-bryozoan habitats of Backstairs Passage are also of significance as a habitat which has been depleted in many other parts of the region, with the advent of prawn trawling in Gulf St Vincent in 1968, which removed much of the deepwater bryozoan and sponge-bryozoan assemblages of the gulf (M. Olesen, pers.comm.). Orontes Shelf The 10-20 km wide Orontes Shelf is an extensive seagrass-reef shoal system that skirts the eastern coastline of Yorke Peninsula, from the Marion and Troubridge Shoals, north to Port Vincent. The calcreted Pleistocene shell bed forms extensive flat rocky surfaces, or low erosional escarpments (5m or more high) and provides excellent habitat for a diversity of marine life, including sponges, ascidians, and reef molluscs, and is also an outstanding mixed fishing ground (Shepherd & Sprigg 1976). The diversity and productivity of the area, particularly on the southern reefs, is enhanced by strong tidal currents. Historically, the Orontes Shelf region was one of the major commercial greenlip abalone (Haliotis laevigata) fishing grounds in South Australia, prior to the outbreaks of the protozoan parasite, Perkinsus olseni, in 1985 and 1986 (Goggin & Lester 1995). Coastal Wetlands of National Importance A Directory of Important Wetlands in Australia (ANCA 1996) list the following coastal wetlands of national importance along Gulf St VincentFleurieu Peninsula Coast: − − − − − − Point Davenport Wills Creek Clinton Port Gawler and Buckland Park Lake Barker Inlet and St Kilda Onkaparinga Estuary Other Recognised Significance Areas of Biological In early 1974, the Department of Fisheries advised the Yorke Coast Protection District Board of six significant areas which were under consideration for declaration as Aquatic Reserves. Areas within Gulf St Vincent included: − tidal inlet at education/purposes) − mangrove areas from Price to Port Wakefield (for fisheries management and conservation purposes) − intertidal reefs between Black Hill and Troubridge Point (for education purposes) the islands and surrounding waters of Althorpe and neighbouring islands (as a conservation reserve to protect the Blue Groper population) − − Coobowie and the reefs at Cape conservation purposes). Elizabeth (for (for None of these areas has since been declared as Aquatic Reserves. However, Gleesons Landing is now a recognised sanctuary for Southern Rock Lobster. Page 155 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS 1.2 described. Aboriginal sites, objects and remains are protected under the South Australian Aboriginal Heritage Act (1988), and a register of such sites, objects and remains is kept with the Aboriginal Heritage Branch of the South Australian Department of Environment and Planning. Physical Orontes Bank Geological Monuments There are 28 areas of geological significance in the Gulfs region which are associated with the coastline or offshore waters. These areas have been identified and recognised as "geological monuments" by the South Australian Museum and the Geological Society of Australia, and include the following sites: 1. Giles Point 2. Stansbury 3. Port Vincent (1 km north) 4. Port Julia Greensand 5. Pine Point 6. Hallett Cove 7. Witton Bluff, South Bank 8. Onkaparinga Mouth-Seaford 9. Maslin Bay-Aldinga Bay 10. Sellicks Beach 11. Myponga Beach 12. Carrickalinga Head 13. Normanville Sand Dunes 14. South Yankalilla Beach (Little Gorge Area) 15. Second Valley Harbour (coastal cliffs) 16. Middleton Beach 17. Cape Jervis 18. Encounter Bay region (Port Elliot including Commodore Point, Pullen Island, The Sisters Rocks and Freeman Knob) 19. Deep Creek 20. Tunkalilla Beach (including the old cliff line) 21. Headland between Waitpinga Beach and Parsons Beach 22. West Island, King Beach and King Point 23. Rosetta Head/The Bluff, Petrel Cove and Wright Island 24. Victor Harbor, Granite Island and Seal Island 25. Victor Harbor (banks of the railway cutting) Further details of these areas are supplied in the relevant regional biounit descriptions below. 2 SIGNIFICANT CULTURAL HISTORICAL FEATURES OR The following description of Aboriginal and European history in the Gulfs province is necessarily brief and selective. The aim is to give the province a historical perspective with emphasis on coastal and maritime history. Only details of Aboriginal historical and cultural sites that have been published in the available literature are 2.1 Aboriginal The Yorke Peninsula coast was, in the past, intensively occupied by Aboriginals of the Narungga tribe and important evidence of this occupation is to be found at many places. Most evidence of Aboriginal occupation is to be found in the sand dunes along the west coast of the Peninsula. Amongst the most important areas are in the Cape Elizabeth/Tiparra Springs dunes and in the dunes north of Moonta Bay. Other west coast areas where evidence is know to exist are in the dunes between Port Hughes and Cape Elizabeth and in those south of Port Victoria. Other known areas are at Point Yorke on the South Coast and at Black Point and Tiddy Widdy on the east coast. The latter two areas are of considerable importance, though the Tiddy Widdy dunes have been looted. The Fleurieu Peninsula was inhabited by the Kaurna people. Evidence of Aboriginal occupation has been found along the coastal regions, but extensive development and agriculture has destroyed many significant sites. 2.2 European Early Discoverers The first explorer to touch the South Australian coast was the Dutchman, Francors Thyssen in the 'Gulden Zeepard' in 1627. He sailed eastwards across the Bight as far as the Nuyts group of islands, but turned back because of the inhospitable coast. It was more than 150 years later when the Frenchman D'Entrecasteaux sailed eastwards to the Nuyts Archipelago and then to Van Diemen's Land. The exploration and mapping of the coast of Eyre Peninsula began with the Englishman Flinders and his crew who arrived aboard the 'Investigator' at Fowlers Bay on 28 January 1802. He proceeded in an easterly direction charting the outline of the Peninsula and naming features after places in his native Lincolnshire, after supporters of the voyage, and from the way the features appeared to him (eg. Smoky Bay). He also named islands after his crew, such as at Cape Catastrophe where the Master of the 'Investigator' (Thistle), and seven crewmen were drowned. Memory Cove was so named to commemorate those lost. Page 156 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Following the initial discoverers came whalers and sealers, and before settlement had begun, there was a thriving whaling, sealing and fishing industry. The remains of early sealers' huts and whaling stations may still be seen on some of the beaches and offshore islands. The South Australian Company, in addition to its operations at Encounter Bay on Fleurieu Peninsula, established whaling stations on Thistle Island at the foot of Spencer Gulf and at Sleaford Bay on the tip of Eyre Peninsula. Port Lincoln was founded in March of 1839, and increased settlement and agriculture began on a broader scale in the region. Gulf St Vincent was discovered in March 1802 after Flinders discovered the Yorke Peninsula when he sailed down the western side of it after turning back from the head of Spencer Gulf. Flinders named Spencer Gulf after Earl Spencer, Yorke Peninsula after Charles Philip Yorke, and Gulf St Vincent after Earl St Vincent. All three men were at some stage acting as the First Lord of the Admiralty. Following Flinders, sealers, whalers and land speculators soon settled the coastal areas of the Gulfs. Coastal Ports The chief method of communication between Adelaide and the coastal settlements was by sea. Port Clinton, established in 1863 to supply the mining towns of Moonta and Kadina, was the first of the ports on the Gulf St Vincent coast of Yorke Peninsula. At the minor Gulf St Vincent ports of Port Price, Port Julia, Pine Point, Wool Bay and Coobowie, townships grew up at the landward ends of the jetties constructed for the ketch trade, which dwindled away until the last of the old time vessels ceased crossing the Gulf in the mid 1960s. These jetties are now important reminders of that time and those that remain are now used by tourists, divers and fishers. region include the `Hougamont’, `Clan Ranald’,`Willyama’, `Zanoni’, and `Victoria’. The earliest known shipwreck for South Australia, the `South Australian', occurred in Encounter Bay in 1837. Along the Yorke Peninsula coast, nearly a hundred shipping accidents have been recorded from cutters to clippers and steamers. The number of deaths in the accidents has been relatively small. Half of these incidents occurred on the south coast of Yorke Peninsula, from Cape Spencer to Troubridge Shoal. Another three dozen occurred on the west coast from Reef Head to Cape Elizabeth and half of these occurred near Wardang Island and in the harbour of Port Victoria. For many years Troubridge Shoal was the worst spot for wrecks, even after the lighthouse had been built there in 1856, whilst the greatest number of deaths (40) in any wreck on the Peninsula occurred with the loss of the `Clan Ranald’ in 1909. 3 The Gulfs Province is the most represented in terms of Marine Protected Areas (or MPAs) of all the coastal provinces in South Australia. As such, 9 of the 13 Aquatic Reserves (69%) which have been declared in South Australia, occur in this province. No large, multiple use Marine Parks have been declared in this region. As with other coastal provinces, the majority of MPAs in this region comprise `netting closures', many of which have generally not been formally recognised as MPAs (see Ivanovici 1985, McNeill 1991). Only one Marine Sanctuary have been declared along this coast (ie. Gleesons Landing). This was established for the protection of the Southern Rock Lobster. − Marine Reserves Troubridge Hill (460 ha) St Kilda-Chapman Creek (870 ha) Barker Inlet-St Kilda (2,055 ha) Port Noarlunga Reef & Onkaparinga Estuary (300 ha) Aldinga Reef (505 ha) − Marine Parks None − − − − Shipwrecks There are a large number of shipwrecks within Gulf St Vincent – Investigator Strait region. Within gulf waters north of a line from Cape Jervis to Troubridge Point and in Encounter Bay, designated wrecks are protected by the (South Australian) Historic Shipwrecks Act 1981. In the waters of Investigator Strait and Backstairs Passage, the (Commonwealth’s) Historic Shipwrecks Act 1976 applies. All wrecks older than 75 years old are granted automatic protection under the Commonwealth legislation, whether designated or not. The most notable wrecks in the CURRENT CONSERVATION STATUS OF GULF ST VINCENT Page 157 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Netting Closures − − − − − − − − − − − − − Edithburgh Coobowie Stansbury Price Port Wakefield Port Adelaide (upstream from North Arm) Outer Harbour and Port Adelaide River Metropolitan beaches Patawalonga Lake Onkaparinga River Parson's Beach Waitpinga Beach Hindmarsh and Inman Rivers Page 158 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS XIX MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE STURT AND INVESTIGATOR BIOUNITS This coastal region encompasses 2 biounits: the inshore Sturt Biounit and the offshore Investigator Biounit. The Sturt Biounit extends from West Cape on the `foot' of Yorke Peninsula, east to Troubridge Hill (down to a depth of 30 metres), and covers an area of 183,058 ha and a coastal distance of approximately 105 km, excluding offshore islands. Offshore islands in the biounit include the Althorpe Islands (Althorpe, Haystack and Seal Islands), and Royston, Middle and Chinamans Hat Islands. The Investigator Biounit is defined by the 30m bathymetric contour and encompasses the offshore waters of Investigator Strait. MARINE BIOGEOGRAPHY 1 3 Major Inshore Habitats OCEANOGRAPHY Wave energies are high from West Cape to Cape Spencer and then moderate from Cape Spencer to Sultana Point. 2 GEOLOGY AND GEOMORPHOLOGY 28 BIOLOGY COASTAL − Major intertidal habitats in the region include mostly sheltered bays, rocky shores and sandy beaches. − Of the total inshore subtidal habitats mapped in the Sturt Biounit (34,164 ha), seagrass meadows comprise 25,611 ha (75.0%), reefs comprise 5 088 ha (14.9%), and sandy bottoms comprise 3,465 ha (10.1%). Dunes and limestone cliffs dominate the coastal geomorphology of this biounit. Major Benthic Communities At Cape Spencer there are aeoleonite and limestone cliffs, followed by a wide dune belt at Marion Bay. Hillock Point is aeoleonite and limestone cliffs with a small section of dunes. At Point Davenport Conservation Park, a low dunal area of considerable change in coastal position occurs. The position of the point is continually being altered by the growth of spits and the joining up of those with the land. The area includes a stranded lagoon occasionally replenished by extreme tides, and an open tidal inlet. Sturt Bay is a 20 km section of coast with a well formed foredune and is backed by a series of parallel dunes which are the largest and highest array of parallel dunes in the district. Macroalgal − On high wave-exposed coasts in this region (eg. West Cape, Cable Hut Bay, Cape Spencer, Althorpe Island, Haystack Island, Troubridge Hill), rocky shores are dominated in shallow waters (ie. <5m) by Ecklonia radiata, Acrocarpia paniculata, Carpoglossum, species of Cystophora (C.moniliformis, C.racemosa, C.siliquosa, C.platylobium), and an understorey of red algae (Plocamium, Phacelocarpus), green algae (Caulerpa flexilis, Codium galeatum) and articulated coralline algae (ie. Haliptilon, Cheilosporum, Amphiroa, Metagoniolithon). In deeper waters (ie. 10-15m), reefs are dominated by Ecklonia, Seirococcus axillaris, Sargassum fallax, and a mixed red algal assemblage (ie. Plocamium preissianum, Sonderopelta, Pterocladia lucida, Ballia callitricha, Rhodymenia). 28 From Yorke Coast Protection District Study Report (Wynne 1980). Page 159 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS − On moderately exposed coasts (eg. around Rhino Head, Hillock Point), rocky shores are dominated in shallow waters (ie. 5m) by species of Cystophora (C.siliquosa, C. moniliformis, C.brownii), Scaberia agardhii, Scytothalia dorycarpa, Caulerpa flexilis and an understorey of Lobophora variegata. − In sheltered areas (eg. around Haystack Island, Cootes Hill), rocky shores are dominated by species of Sargassum (S.fallax, S.verruculosum, S.heteromorphum, S.linearifolium), species of Cystophora (Cystophora monilifera, C.moniliformis, C.expansa), and an understorey of Lobophora variegata, Caulerpa flexilis and C.trifaria, and Plocamium angustum. Seagrasses − The wetland is an important habitat for waterbirds, including a number of wader birds that occasionally visit the area, and contains the only conserved stands of Swamp Paperbark, Melaleuca halmaturorum on Yorke Peninsula. Threatened species of waterbirds include the Hooded Plover, Thinornis rubricollis (Nv, Sv), Latham’s Snipe, Gallinago hardwickii (Sv), Musk Duck, Biziura lobata (Sv), Eastern Curlew, Numenius madagascariensis (Sv) and Fairy Tern, Sterna nereis (Sv). A total of 26 species of waterbirds have been recorded in the area: 9 are listed under international treaties. Islands of Recognised Conservation Value • − Althorpe Islands Conservation Park The islands and surrounding waters of Althorpe Island and neighbouring islands have a distinctive aquatic flora and fauna characteristic of rough-water coasts. They are especially well known for their populations of Blue Groper, seals and are important seabird breeding grounds. Dolphins are also found in this area. Colonies of Australian Sea Lions (Neophoca cinerea) have been recorded on Little Althorpe (North and South), Althorpe, Haystack and Seal Islands (Robinson & Dennis 1988, Gales et al. 1994). However, only Little Althorpe (North and South) and Seal Island represent possible breeding sites (Gales et al. 1994). Likewise, colonies of New Zealand Fur Seals (Arctocephalus forsteri) have also been recorded on Althorpe, Little Althorpe (South) and Seal Islands (Shaughnessy et al. 1994). However these probably represent haul out and basking sites only. The conservation park includes Haystack Island and Seal Island. • − Troubridge Island Conservation The Troubridge Island Conservation Park (not to be confused with the Troubridge Hill Aquatic Reserve off the mainland) is an important bird breeding area and also has historical features such as the lighthouse and associated cottages. However, this island of sand is subject to the strong wave action of the Southern Ocean, resulting in it eroding heavily on one side, but building out elsewhere. As a result, the island shifts its position. Extensive seagrass meadows occur in Marion, Foul, Sturt and Waterloo bays, and also in the lee of islands (eg. Althorpe, Haystack islands). Meadows are dominated by species of Posidonia (P.sinuosa, P.angustifolia), Amphibolis antarctica, and also, Halophila australis. Coastal and Offshore Islands (or Reefs) − Althorpe, Little Althorpe (North and South), Haystack and Seal Islands (Althorpe Islands Conservation Park). − Royston, Middle and Chinamans Hat Islands (part of Innes National Park). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance − Point Davenport (and the Point Davenport Conservation Park) has been identified as a wetland of national importance (see ANCA 1996). Point Davenport is a rare example of a stranded coastal lagoon on Yorke Peninsula. The semi-stranded tidal lagoon enters the sea via a tidal inlet, and is inundated during extreme high tides usually once or twice a year. Page 160 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Seagrasses cover approximately 2,436 km2 in Gulf St Vincent, with most of the seagrasses located in the northern reaches of the gulf (ie. Clinton Biounit, 132,576 ha), in the Orontes Bank region along the eastern coast of Yorke Peninsula (ie. Orontes Biounit 51,713 ha), and along the southern coast of Yorke Peninsula in Investigator Strait (Sturt Biounit, 23,229 ha). Other Areas of Recognised Conservation Significance • − • − • − Innes National Park Preserves the largest area of natural bushland remaining on the Yorke Peninsula, and preserves the habitat of the Western Whipbird. It is characterised by a sandy undulating plain with dunes and salt lakes, or low cliffs along the coastline. The magnificent and spectacular coastal scenery is one of the major attractions of this park, which includes cliffs, wave cut platforms, rocky headlands and sandy beaches. Typical coastal dune and clifftop vegetation is backed by mallee and teatree scrub. It is still possible to see the remains of the shipwreck `Ethel' near Reef Head. Royston, Middle and Chinamans Hat islands are included in the national park. Troubridge Hill Aquatic Reserve. Consists of intertidal and subtidal reef platforms: coarse-grain sandy bottom and sandy beaches. The intertidal reef platform extends 50m offshore before falling away sharply to 15m depth. The crevices and overhangs are colonised by many benthic organisms including gorgonian corals. The wreck of the `Clan Ranald' lies in 22m depth within the reserve. The area from Troubridge Point to Port Moorowie is on the Register of the National Estate. Troubridge Shoals. Troubridge Shoals have large sponge `gardens'. The Troubridge region (including Troubridge and Cootes Hills, Troubridge Point and Marion Reef) contains abundant and diverse assemblages of large red algal species (Osmundaria, Cladurus, Erythroclonium, Areschougia) and other mixed red species. The dominance of large red algal species is an unusual feature at a statewide biogeographic level. The Troubridge area is also the site where the newly described (Womersley, in prep.) Amphiroa gracilis is locally abundant. Seagrass Meadows − The seagrass meadows of this biounit represent the third largest areas in Gulf St Vincent, after the Clinton and Orontes Biounit. These extensive seagrass meadows flourish in the shallow waters, generally in waters less than 15m, and provide the basis for the significant productivity of the region in terms of fisheries and prawn production. 1.2 − Physical Sturt Bay: considered to be a "magnificent stretch of beach"29 with the largest and highest array of parallel dunes in the district as a scenic backdrop. Geological Monuments − Meteor Bay (2 km east of Hillock Point): Proterozoic basement rocks on the shore platform. − Point Moorowie: Permian glacigenes and unconformity with Ardrossan Clays and sand rock. The site is also on the Register of the National Estate. 2 2.1 OTHER VALUES Commercial Fisheries A wide variety of commercial fishing occurs in the coastal and offshore waters of this biounit. Single species fisheries include Southern Rock Lobster, Abalone and Western King Prawn. There is also a large marine scalefish industry in the region. Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours, respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). 29 From Yorke Coast Protection District Study Report (Wynne 1980). Page 161 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Southern Rock Lobster In 1995/96 and 1996/97 a total of 19 and 19 licensed operators fished in the south western and southern Yorke Peninsula (and Investigator Strait) region (ie. Fishing Zone 40), catching approximately 71,795 and 64,785 kg of lobsters, respectively (or 1.40% and 1.27% of the total catch for Southern Rock Lobster in South Australian waters). 2.2 There is currently no aquaculture in the area. The Gulf St Vincent/Fleurieu Aquaculture Management Plan (Berggy 1996) proposes the following aquaculture development in this region: Lower Yorke Peninsula Policy Area − Lower Yorke Peninsula Zone (all coastal waters from Cape Spencer east to Marion Bay/Stenhouse Bay Aquaculture Zone, including Althorpe Islands, Haystack Island and Seal Island) – zoned for maintenance of visual and conservation values. Licenses will not be considered for aquaculture development in this zone. − Marion Bay/Stenhouse Bay Aquaculture Zone (coastal waters of Stenhouse and Marion bays, within 3nm of the coast) – zoned for aquaculture development. Licenses will be considered for a total of 20ha of aquaculture development in this zone, excluding the cultivation of the Pacific Oyster. − Foul Bay/Moorowie Management Zone (coastal waters of Foul, Sturt and Waterloo bays, within 3nm of the coast, from west of Hillock Point to Troubridge Hill) – zoned for aquaculture development. Licenses will be considered for a total of 20ha of aquaculture development in this zone, excluding the cultivation of the Pacific Oyster. Abalone Some Greenlip and Blacklip Abalone is commercially harvested in the western section of this biounit (ie. MapCode 23D, Stenhouse Bay, see Pondalowie Biounit), however there is no commercial harvest of either Blacklip or Greenlip Abalone in the Sturt Bay, Troubridge Shoals and Sultana Point region. Marine Scalefish Fisheries During 1995/96 and 1996/97, 54 and 51 commercial licence holders (made up of Marine Scalefish, Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the in the south western and southern Yorke Peninsula (and Investigator Strait) region (ie. Fishing Zone 40), respectively. License holders expended approximately 1,742 and 1,668 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 40) represented 200,171 kg in 1995/96 and 211,150 kg in 1996/97(or 1.93% and 2.08% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Marion Bay: 3 Rock Lobster, 1 restricted marine scalefish, 3 unrestricted marine scalefish − Port Moorowie: 1 restricted marine scalefish, 1 unrestricted marine scalefish − Foul Bay: 4 unrestricted marine scalefish − Stenhouse Bay: 1 unrestricted marine scalefish Aquaculture 2.3 Recreation and Tourism Fishing − Cape Spencer: beach and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Sweep, Garfish, Tommy Rough, Toothbrush Leatherjacket and Silver Drummer. − Stenhouse Bay: jetty and rock fishing. Major species: Yelloweye Mullet, Sweep, Garfish, Tommy Rough and Southern Calamari. − Marion Bay: boat and jetty fishing. Major species: King George Whiting, Yelloweye Mullet, Snapper, Snook, Garfish, Tommy Rough and Southern Calamari. Page 162 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS − − Hillock Point and Butlers Beach: beach and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Mulloway, Snook, Sweep, Garfish, Tommy Rough, Toothbrush Leatherjacket and Silver Drummer. − Butlers Beach: camping. − Marion Bay and near Point Yorke: scenic lookouts. − Lighthouse, west of Troubridge Point. Troubridge Point: beach and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Sweep, Tommy Rough, Toothbrush Leatherjacket and Silver Drummer. − Troubridge Hill Aquatic Reserve: SCUBA diving, recreational fishing, historic shipwreck (ie. `Clan Ranald’), coastal scenic qualities. Tourism − Stenhouse Bay jetty: popular for fishing and SCUBA diving. − Innes National Park: camping, spectacular coastal scenery and SCUBA diving. The small holiday and fishing village of Pondalowie Bay, and South Island are popular camping sites and are excluded from the national park. The Innes National Park region is a very popular site for SCUBA diving and contains many spectacular dives. Pondalowie Bay, Reef Head and the Gap, Emmes Reef (5 miles off from the Gap), Haystack Island and the Althorpe Islands, Chinamans Hat Island, and the Stenhouse Bay jetty, are all recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). All these reef dives are excellent dives, with abundant marine life, including seals and sea lions (ie. Althorpe Islands, Haystack Island, Seal Island), but require good weather and/or generally experienced divers. Stenhouse Bay jetty has abundant marine life on its pylons and is also a good, accessible site for underwater photography. − SCUBA diving: other recognised and popular dive spots in the region include Foul Bay and Cable Hut Bay, `Clan Ranald’ shipwreck, Troubridge Point and Troubridge Hill, and Troubridge Shoal. All are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). 2.4 Scientific Research and Education − Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region (Abalone and marine scalefish); regular research and monitoring of larval fish stocks; regular research and monitoring of Blacklip and Greenlip Abalone field stocks. − The intertidal reefs between Black Hill and Troubridge Point are used on a regular basis for teaching and research purposes by the University of Adelaide. An educational reserve was proposed for this area by the Department of Fisheries in 1974. 2.5 Adjacent Land Use National and Conservation Parks − Innes National Park (9,232 ha): includes: Royston, Middle and Chinamans Hat islands. − Althorpe Islands Conservation Park (25 ha): includes Haystack Island and Seal Island. − Point Davenport Conservation Park (239 ha). − Troubridge Island Conservation Park (314 ha). Urban Centres No major urban centres, although there are numerous holiday shacks along the coast. Marion Bay has a permanent mooring facility for commercial and recreational craft. Agriculture/Industry The adjacent land in this biounit is predominantly agricultural. Page 163 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS 2.6 Significant Cultural and Historical Features − 4 Aboriginal Not known. Formby Bay - Innes National Park30 − European Shipwrecks − The Investigator Strait is notable for a number of shipwrecks along its coast. The State Heritage Branch of the Department of Environment and Aboriginal Affairs lists 26 known wrecks along the coast between Cape Spencer and Troubridge Point, and there are others whose locality is not known (Ashman 1996). Some of the more notable wrecks include: − `S.S. Clan Ranald’ (1900-1909): a single screw turret deck steamer which sank off Troubridge Hill. 44 of the 63 crew were lost. The wreck is located within Troubridge Hill Aquatic Reserve. − `Iron King’ (1867-1873): a three-masted iron ship that ran aground on Troubridge Shoals. − `Marion’ (1850-1851): a three-masted wooden ship that struck a reef just south of Troubridge Shoals. Its remains are located on Marion Reef, a shallow limestone reef, south of Troubridge Island. − `Ethel’: an iron barque of 700 tons that went ashore in January 1904 near Reef Head. Retrieval attempts were unsuccessful, and today one of her boilers can still be seen poking out of the sand near Reef Head. 3 CURRENT CONSERVATION STATUS OF THE STURT BIOUNIT − Marine Reserves Troubridge Hill (460 ha) − Marine Parks None − Netting Closures None AREAS OF HIGH CONSERVATION VALUE IN THE STURT BIOUNIT Prime IUCN Conservation Values: biodiversity, education, social, cultural values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to humaninduced change), biogeographic (representative marine habitats, geological monuments-Browns Beach), ecological (diversity of marine habitats, high marine biodiversity, reef fish populations Blue Groper, breeding populations-Little Penguins, Silver Gulls, seabirds-Black-faced Cormorants, Pied Cormorant, Reef Heron, Pied Oyster Catcher, Sooty Oyster Catcher, Grey Plover, Hooded Dotterel, Red Neck Stint, Black Winged Stint, Pacific Gull, Caspian Tern, Crested Tern, Silver Gull, Shy Albatross, Little Pied Cormorant, Banded Plover, Banded Stilt, Little Tern), economic (tourism, Greenlip Abalone, Southern Rock Lobster, marine scalefish fisheries), social (`Ethel' shipwreck, recreation, diving, education-Gleesons Landing-Daly Head), national significance (potential for listing on Register of National Estate), practicality (insulation, accessibility, compatibility-adjacent to Innes National Park). Althorpe Islands 31 − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological, (high marine biodiversity, breeding colonies and haul out sites for Australian Sea Lions and New Zealand Fur Seals, reef fish populations-Blue Groper, colonies of `vulnerable' Fairy Terns, Black-faced Shags, Little Penguins, White-faced Storm Petrels, White-bellied Sea Eagles), economic (abalone, rock lobster fisheries, tourism), social (recreation, diving), practicality (insulation, compatibility-adjacent to Althorpe Islands Conservation Park). 30 Gleesons Landing to Daly Head was nominated for establishment as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, for educational purposes (Wynne 1980). 31 The islands and surrounding waters of Althorpe Island and neighbouring islands were nominated for establishment as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, as a conservation reserve to protect populations of Blue Groper (Wynne 1980). Page 164 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – STURT AND INVESTIGATOR BIOUNITS Point Davenport Conservation Park − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, social values (IUCN Category II). IUCN Selection Critera: naturalness (not subjected to human-induced change), biogeographic (rare coastal habitat, geological monuments-Port Moorowie, Sturt Bay) ecological (extensive seagrass meadows, threatened species of waterbirds-Hooded Plover, Eastern Curlew, Fairy Tern, nursery, feeding area for economic species-marine scalefish), economic (marine scalefish fisheries, tourism), social (recreation, aesthetic values), national significance (Wetland of National Importance-Point Davenport Conservation Park, potential listing on Register of National Estate), practicality (insulation, compatibilityadjacent to Point Davenport Conservation Park). Troubridge Shoals – Marion Shoals − 32 Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological, (range of coastal wetland habitats, breeding colonies Little Penguins, Black-faced Shag, Pied Cormorant, Crested Tern, Silver Gull, `vulnerable' Fairy Terns), economic (marine scalefish fisheries, Southern Rock Lobster, tourism), social (historic shipwrecks `SS Clan Ranald', `Iron King', `Marion', recreation, diving, yachting), practicality (practicality, compatibility, Troubridge Hill Aquatic Reserve, Troubridge Island Conservation Park). 32 The intertidal reefs between Black Hill and Troubridge Point were nominated for declaration as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, for marine educational purposes (Wynne 1980). Page 165 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT XX MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE ORONTES BIOUNIT This biounit extends from Troubridge Hill to Ardrossan on the eastern side of Yorke Peninsula and covers an area of 183,762 ha. The biounit faces east into Gulf St Vincent. Erythroclonium angustum, Osmundaria, Plocamium spp. Cliftonaea, Cladurus, Areschougia); mixed corallines (Amphiroa gracilis [a newly described species] and A.anceps; Haliptilon, Cheilosporum, Metagoniolithon) some mixed Sargassum (S.decipiens, S.fallax, S.linearifolium, S.verruculosum); and some mixed green algae (Caulerpa brownii, Codium pomoides, Dictyosphaeria). MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This area is typified by low wave energies. 2 GEOLOGY AND GEOMORPHOLOGY 33 COASTAL From Sultana Point to Ardrossan, the coastal geomorphology is dominated by limestone cliff slopes. A few areas of sandy beaches with small dunes occur at Stansbury, Port Vincent and Black Point. − On moderately exposed shores and reefs (eg. Troubridge Point), rocky areas are dominated in shallow areas (ie. 5m) by Cystophora moniliformis, diverse mixed reds (Erythroclonium, Rhabdonia, Areschougia, Heterosiphonia, Webervanbossea, Dasya, Laurencia, Euptilota, Ptilocladia, Asparagopsis, Champia); some mixed Sargassum spp. (S.decipiens, S.lacerifolium, S.spinuligerum); and an understorey of Lobophora variegata. − On sheltered shores and reefs (eg. Pine Point, Adrossan), rocky areas are dominated in shallow areas (ie. 5m) by Sargassum spp. (S.decipiens, S.lacerifolium, S.spinuligerum), the red alga, Botrycladia obovata and Caulocystis ulvifera.; Cystophora moniliformis, diverse mixed reds (Erythroclonium, Rhabdonia, Areschougia, Heterosiphonia, Webervanbossea, Dasya, Laurencia, Euptilota, Ptilocladia, Asparagopsis, Champia); some mixed and an understorey of Lobophora variegata. Wide muddy tidal flats occur at Salt Creek Bay, together with a tidal inlet. At Ardrossan there are spectacular eroding clay cliffs. 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly sheltered, low rocky shores, bays and some sandy beaches. − Of the total inshore subtidal habitats mapped in the biounit (91 539 ha), seagrass meadows comprise 51 713 ha (56.5%), reefs comprise 33 745 ha (36.9%), and sandy bottoms comprise 6 081 ha (6.6%). Major Benthic Communities • − Macroalgal On high wave-exposed shores and reefs in the region (eg. Troubridge Hill, Marion Reef), reef areas are dominated in shallow areas (ie. 5m) by mixed species of Cystophora (C.moniliformis, C.racemosa, C.siliquosa, C.platylobium); Ecklonia radiata; diverse mixed large reds (including locally prolific • − Seagrasses Within this biounit, extensive seagrass meadows occur throughout the Orontes Bank, and in sheltered embayments (eg. Coobowie, Adrossan). Sandy sediments are commonly coloniesed by species of Posidonia (P.sinuosa, P.angustifolia) and Halophila australis, which often occurs adjacent to reef communities and in deep water (ie. 20m). 33 From Yorke Coast Protection District Study Report (Wynne 1980). Page 166 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT In these deeper water parts of the gulf, the soft sediments are dominated by faunal assemblages, such as bivalve molluscs (ie. scallops, Pinna bicolor), bryozoans, ascidians and holothurians. 1.2 − Physical − Marion Reef, Orontes Bank. − Troubridge Island. The "Orontes Bank" is a major deep-seated geological structure that extends offshore from Edithburgh to the northern part of the gulf. The edge of the Gawler Craton has produced an intense magnetic anomaly associated with it. The exposed tertiary sediments form a shallow bank extending from approximately Stansbury to Port Julia, and is a few hundred metres wide. Associated with these sediments is modern reefal activity and productivity. Rivers/Estuaries Geological Monuments Coastal and Offshore Islands (or Reefs) − Salt Swamp Creek (Coobowie). − Giles Point: coastal cliffs, consisting of an outcrop of Pliocene Hallett Cove Sandstone and Cainozoic beds. − Stansbury - Port Vincent: limestone with solution features. − Port Vincent (1 km north): coastal faulting and Permian erratics. − Port Julia Greensand: Type section and monocline. MARINE CONSERVATION VALUES 1 1.1 − − SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Seagrass Meadows The seagrass meadows of this biounit represent the second largest areas in Gulf St Vincent, after the Clinton Biounit. These extensive seagrass meadows flourish in the shallow waters, generally in waters less than 15m, and provide the basis for the significant productivity of the region in terms of fisheries and prawn production. Seagrasses cover approximately 2,436 km2 in Gulf St Vincent, with most of the seagrasses located in the northern reaches of the gulf (ie. Clinton Biounit, 132,576 ha), and in the Orontes Bank region along the eastern coast of Yorke Peninsula (ie. Orontes Biounit 51,713 ha), and also, along the southern coast of Yorke Peninsula in Investigator Strait (Sturt Biounit, 23,229 ha). Extensive beds of bryozoans associated with the exposed sediments of "Orontes Bank" (see below). 2 2.1 OTHER VALUES Commercial Fisheries The major single species fisheries in this area is the Western King Prawn. There is also a substantial marine scalefishery in the region. Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours (ie. 86.27 and 65.09 kg/hr, Catch Per Unit Effort), respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). Page 167 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT Abalone Commercial harvesting of Greenlip Abalone is neglible within the Orontes Biounit, (ie. MapCode 22B, 24B-D, Sultana Point to Ardrossan region). No Greenlip were harvested in this region during 1995/96. No Blacklip Abalone was commercially harvested in this region during 1994/95 and 1995/96. 2.2 Aquaculture Oyster farming, involving both the native oyster, Ostrea angasi and later the Pacific Oyster, Crassostrea gigas, has been carried out intermittently at Stansbury for many years One lease is currently in operation at Stansbury. The Gulf St Vincent/Fleurieu Aquaculture Management Plan (Berggy 1996) proposes the following aquaculture development in the region: Marine Scalefish Fisheries Gulf St Vincent West Policy Area During 1995/96 and 1996/97, 37 and 30 commercial licence holders (made up of Marine Scalefish, and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the Orontes Biounit region (ie. Fishing Zone 34), respectively. License holders expended approximately 1958 and 1247 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 34) represented 113,844 kg in 1995/96 and 75173 kg in 1996/97(or 1.09% and 0.74% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following is an approximate number of licenses which are registered in this area: − Port Vincent: 3 Rock Lobster, 6 unrestricted marine scalefish − Coobowie: 1 restricted marine scalefish, 2 unrestricted marine scalefish − Edithburgh: 2 restricted marine scalefish, 7 unrestricted marine scalefish − Stansbury: 1 restricted marine scalefish, 4 unrestricted marine scalefish − Port Julia: 2 unrestricted marine scalefish − Ardrossan: 1 experimental crab, 1 restricted marine scalefish − Troubridge Shoals Zone (coastal waters from Troubridge Point to Edithburgh jetty) – zoned for scenic and conservation uses. Licenses will not be considered for aquaculture development in this zone. − Coobowie Bay Aquaculture Zone (coastal waters of Coobowie Bay, from Edithburgh jetty to Giles Point) – zoned for aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development in this zone, excluding bivalve culture using racks. − Stansbury Aquaculture Zone (coastal waters, within 1km of the coast, from Oyster Bay to North Spit) – zoned for aquaculture development. Licenses will be considered for a total of 80ha of aquaculture development in this zone. − Yorke Peninsula Inshore Management Zone (inshore waters, within 2nm of the coast, from North Spit to Rogues Point and Giles Point to Stansbury Aquaculture Zone) – zoned for aquaculture development. Licenses will be considered for a total of 100ha of aquaculture development in this zone. − Yorke Peninsula Offshore Management Zone (offshore waters, from 2nm to offshore boundary of policy area) – zoned for offshore aquaculture development. Licenses will be considered for a total of 100ha of aquaculture development in this zone. − Ardrossan Zone (coastal waters surrounding the port of Ardrossan) – zoned for commercial, navigation and recreational uses. Licenses will not be considered for aquaculture development in this zone. Page 168 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT 2.3 Recreation and Tourism − SCUBA diving: Troubridge Shoal (also containing the wreck of the `Iron King’), Coobowie artificial reef, the `Zanoni’ shipwreck (off Ardrossan), and the Edithburgh, Port Giles, Wool Bay and Ardrossan jetties are all popular and recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Edithburgh jetty is recognised as one of the best jetty dives in South Australia and is a popular dive training site and location for underwater photography. Most dives, except Troubridge Shoal are suitable for novice divers. Fishing − Edithburgh, Tapley Shoal and Troubridge Shoals: boat, jetty and shore fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Snapper, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket and Southern Calamari. − Port Giles: jetty fishing. Major species: King George Whiting, Snapper, Snook, Garfish, Tommy Rough, Trevally, Silver Drummer and Southern Calamari. − Stansbury: jetty fishing. Major species: King George Whiting, Snapper, Snook, Garfish, Tommy Rough, Trevally, Silver Drummer and Southern Calamari. − Port Vincent: boat and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Tommy Rough and Southern Calamari. − Ardrossan: boat and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Tommy Rough and Southern Calamari. − 2.4 − Port Vincent Primary School and Aquatic Centre plays a major role in school-based marine and coastal educational activities in the Yorke Peninsula region. The centre offers a range of courses and educational activities on marine and coastal habitats and species, utilising the local environments of Port Vincent, and also hosts a wide range of marine aquaria for project work. The centre has received several national awards for its marine educational activities and also provides a wide range of outdoor activities, including snorkelling, for students. − Salt Creek Bay (Coobowie) is a significant site for scientific research and education into marine ecological processes. The tidal inlet and rocky shores of the bay are used both, for marine biological research and education. A marine research field station is located at Coobowie and although, it is owned by the University of Adelaide, it is frequently used by various institutions, including the University of Adelaide, Flinders University, Melbourne University and Monash University. While it is frequently used for undergraduate teaching purposes, it is also commonly used by postgraduate research students and visiting interstate and overseas scientists. On occasions the research station has been let to diving clubs, who use it as a base camp when diving in local waters. It is the only marine research field station of it’s type in South Australia. As such, this area was proposed as an educational reserve in 1980 34. There is an artificial reef near Ardrossan (sunken barge) and Giles Point (tyre modules). Tourism − Coobowie: fishing and boating. − Port Vincent: swimming and yachting (has a safe swimming beach). − Ardrossan: boating and fishing. Scientific Research and Education 34 Yorke Coast Protection District Study Report (Wynne (1980). Page 169 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT − The organisms living on the pylons of Edithburgh jetty have been the subject of many of these scientific research studies; primarily to gain an understanding of the life history dynamics of sessile marine organisms (Butler 1982). The pylons of Edithburgh jetty are exceptional diverse and support a host of sessile organisms with at least 30 sponge species, 10 bryozoan species, 20 colonial ascidian species, 9 solitary sea squirt species, 9 tube-building polychaete worm species and 4 barnacle species recorded (Butler 1982). 2.5 − European Shipwrecks − The majority of shipwrecks in this region are associated with Troubridge Shoals, which are regarded as very dangerous waters for navigation and diving. The `Iron King’ on Troubridge Shoals is a popular dive spot, but is very broken up and prone to strong currents. − `Zanoni’ (1865-1867): a 139 foot three-masted composite barque of iron frames and wood planking which sank in a freak storm off Ardrossan. There is a protected zone declared around the `Zanoni’. The `Zanoni’ is a designated Historic Shipwreck under the SA Historic Shipwreck Act 1981. The wreck lies in 18m of water approximately 20 nautical miles north west of Port Adelaide. The depth of water, lack of surge and lack of oxygen and light and no salvage are the main factors that leave the `Zanoni’ in good condition. 3 CURRENT CONSERVATION STATUS OF THE ORONTES BIOUNIT Adjacent Land Use National and Conservation Parks Troubridge Island Conservation Park (314 ha). Agriculture/Industry − Most adjacent land in this biounit is agricultural. − Ardrossan is a deep sea port, shipping bulk grain from the peninsula. There is also a nearby dolomite quarry owned by BHP. Crushed rock for this operation is shipped from Ardrossan. − Ardrossan, Edithburgh and Port Vincent have permanent coastal mooring facilities for commercial and recreational craft. Urban Centres − − Marine Reserves None − Marine Parks None Ardrossan (population 963). − Stansbury (population 520). − Edithburgh (population 400). − Port Vincent (population <250). 2.6 Features − Significant Cultural and Historical − In addition to this total closure, nets are prohibited in waters exceeding 5 metres in depth contained within a line from Sultana Point to Marion Reef buoy, then to Troubridge Island lighthouse and then to a point adjacent to Giles Point. − Coobowie (all waters within a line from the Salt Swamp Creek causeway to the end of the old Coobowie jetty structure and then to Hickies Point). Aboriginal − Black Point is considered to considerable cultural importance. be Netting Closures Edithburgh (all waters south west of a line from Sultana Point to a point on the mainland adjacent to the roadway between sections 185 and 205 Hd Melville. of Page 170 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ORONTES BIOUNIT − 4 Stansbury ( all waters west of a line from the groyne at Oyster Point to a point 200 metres north of the jetty and then south westerly to a point on the mainland 200 metres north of the jetty). Black Point − AREAS OF HIGH CONSERVATION VALUE IN THE ORONTES BIOUNIT Salt Creek Bay 35 − Prime IUCN Conservation Values: research, biodiversity, education, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (`Orontes Bank', Giles Point `geological monument'), ecological, (range of coastal wetland habitats, extensive seagrass meadows, major fisheries nursery and feeding area - King George Whiting, Garfish, Western King Prawn, Port Jackson Shark spawning area), economic (marine scalefish fisheries, tourism), social (education, recreation, artificial reef-Giles Point, diving, yachting), scientific (University of Adelaide Coobowie Research Station, Edithburgh jetty), national (potential for listing on the Register of the National Estate), practicality (accessibility, compatibility). Prime IUCN Conservation Values: cultural values, biodiversity (IUCN Category III). IUCN Identification Criteria: biogeographic (geological monument-Port Julia), ecological (seagrass meadows, major nursery and feeding areas - King George Whiting, Garfish, Western King Prawn, Blue Swimming Crab), economic (marine scalefish fisheries, Western King Prawn, tourism), social (aboriginal significance-Black Point, recreation, yachting). Tiddy Widdy − Prime IUCN Conservation Values: cultural values, biodiversity (IUCN Category III). IUCN Identification Criteria: biogeographic (representative marine habitats), ecological (wetland habitats - mangroves, seagrass meadows, major nursery and feeding areas King George Whiting, Garfish, Western King Prawn, Blue Swimming Crab), economic (marine scalefish fisheries, Western King Prawn, tourism), social (aboriginal significance-Tiddy Widdy, recreation, yachting). Oyster Bay-Port Vincent − Prime IUCN Conservation Values: education, biodiversity, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (`Orontes Bank', geological monuments-Stansbury-Port Vincent, Port Vincent), ecological, (range of marine habitats, seagrass meadows, major fisheries nursery area - King George Whiting, Garfish, Western King Prawn), economic (marine scalefish fisheries, Western King Prawn, tourism), social (education-Port Vincent Primary School and Aquatic Centre, recreation, diving, yachting), practicality (accessibility, compatibility). 35 Salt Creek Bay was nominated for declaration as an Aquatic Reserve by the former South Australian Department of Fisheries in 1974, for marine educational purposes (Wynne 1980). Page 171 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT XXI MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE CLINTON BIOUNIT This biounit extends from Ardrossan on the eastern side of Yorke Peninsula to Marino Rocks (just north of Hallet Cove, metropolitan Adelaide). It includes the upper reaches or `head' of Gulf St Vincent and covers an area of 249,136 ha and a coastal distance of approximately 185 km. MARINE BIOGEOGRAPHY 3 BIOLOGY Major Inshore Habitats 1 OCEANOGRAPHY − Major intertidal habitats in the region include tidal wetlands (ie. mangrove, coastal saltmarshes, tidal mudflats), sandy beaches and some low rocky shores. − Of the total inshore subtidal habitats mapped in the biounit (157,029 ha), seagrass meadows comprise 132,576 ha (84.4%), sandy bottoms comprise 21,173 ha (13.5%), and reefs comprise 3,280 ha (2.1%). This region is one of very low wave energies at the `head' of the Gulf, gradually increasing to moderate at Outer Harbour and Marino Rocks. 2 GEOLOGY AND GEOMORPHOLOGY 36 COASTAL North of Ardrossan the cliffs finish and are replaced by a long beach area with small dunes at Tiddy Widdy Beach. These sandy beaches give way to muddy tidal flats at Price and then to mangrove flats at Clinton. Wide mangrove tidal flats continue relatively unbroken to Sandy Point. From Sandy Point to Middle Beach, the mangroves are gone and replaced by wide tidal flats. The mangrove flats begin again at Middle Beach and continue in a southerly direction until Torrens Island, near Outer Harbour. From Outer Harbour southwards to Marino Rocks, there is a 30 km sandy beach composed largely of silica sand (an unusual feature for beaches in South Australia as most are calcium carbonate) fronting an extensive plain. Originally backed by a multiple foredune system, the beach is now largely built upon or has been removed. There is a gentle offshore gradient from the coast which was originally well covered by seagrass meadows but has now been severely degraded due to effluent and stormwater discharge. Major Benthic Communities • Macroalgal − There are no significant reefal communities in this northern section of this biounit. • Seagrasses − This region is dominated by extensive seagrass meadows and tidal flats. Sandy sediments are commonly colonised by species of Posidonia (P.sinuosa, P.angustifolia) and Halophila australis, which often occurs adjacent to reef communities and in deep water (ie. 20m). In these deeper water parts of the gulf, the soft sediments are dominated by faunal assemblages, such as bivalve molluscs (ie. scallops, Pinna bicolor), bryozoans, ascidians and holothurians. Coastal and Offshore Islands (or Reefs) − None. 36 From Yorke Coast Protection District Study Report (Wynne 1980). Page 172 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT Other substantial communities occur in lower Spencer Gulf (6,000ha), on the west coast of Eyre Peninsula (9,000 ha) and on Kangaroo Island (7,000 ha) (DELM 1993). In Gulf St Vincent, mangroves, and associated coastal saltmarshes, seagrasses and tidal mudflats dominate the upper portion of the Gulf from Port Clinton to Port Adelaide. Rivers and Estuaries − Wakefield River. − Light River. − Gawler River. − Chapman Creek. − Port Adelaide River - Barker Inlet estuary. − Torrens River (which flows out to sea at Henley Beach). − Brown Hill and Sturt Creeks (which drain into the Patawalonga at Glenelg which then flows into the sea). • − Extensive Seagrass Meadows This biounit contains the largest areas of seagrass meadows in Gulf St Vincent, and the second largest in South Australia. Gulf St Vincent (along with Spencer Gulf) contain some of the most extensive areas of temperate seagrass meadows in Australia (Edyvane 1996). These extensive seagrass meadows flourish in the shallow waters of the gulf, generally in waters less than 15m, and provide the basis for the significant productivity of the gulf in terms of fisheries and prawn production. Seagrasses cover approximately 2,436 km2 in Gulf St Vincent, and represent 25% of the total area of seagrasses recorded in South Australia (ie. 9,612 km2). Most of the seagrasses in the gulf are located in the northern reaches of the gulf (ie. Clinton Biounit, 132,576 ha), in the Orontes Bank region along the eastern coast of Yorke Peninsula (ie. Orontes Biounit 51 713 ha), and along the southern coast of Yorke Peninsula in Investigator Strait (Sturt Biounit, 23,229 ha). − The extensive coastal and marine wetlands in this biounit have been conserved in several conservation areas: Clinton Conservation Park, Port Gawler Conservation Park, Barker Inlet Aquatic Reserve and the St Kilda Chapman Creek Aquatic Reserve. − Wills Creek has been identified as a wetland of national importance (see ANCA 1996). The area consists of an extensive, shallow, mangrove tidal estuary, comprising two creeks (Wills Creek and Shag Creek). The wetland provides habitat for migratory waders and is a major site of cormorant breeding activity on the Yorke Peninsula. Threatened species of waterbirds include the Eastern Curlew, Numenius madagascariensis (Sv), Musk Duck, Biziura lobata (Sv), Fairy Tern, Sterna nereis (Sv), Slender-billed Thornbill, Acanthiza iredalei rosinae (Sv), and Whitebellied Sea-Eagle, Haliaeetus leucogaster (Sv). A total of 49 species of waterbirds have been recorded for the area: 18 listed under international treaties. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance • − Extensive Mangrove and Tidal Wetlands. This biounit contains the largest areas of tidal wetlands and mangroves in Gulf St Vincent, and the second largest in South Australia. Gulf St Vincent (along with Spencer Gulf) contains some of the most extensive areas of mangrove forests and tidal wetlands in South Australia (and the largest areas of temperate mangroves in Australia) (Edyvane 1996). Associated with the mangrove habitats are the biologically rich mud flats, coastal saltmarshes and seagrasses. Together, these communities provide key habitats for waterfowl and waders (Close & McCrie 1986), and important feeding, breeding and nursery areas for economically important species of fish and crustaceans (eg. Western King Prawn, King George Whiting, Southern Sea Garfish). Mangrove and saltmarsh communities along the South Australian coast total approximately 82 000 ha, with the largest communities occurring in Spencer Gulf (46,000 ha) and Gulf St Vincent (20,000 ha). Page 173 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT Species of waterbirds which breed in the area include all 4 species of cormorants, Great Cormorant, Phalacrocorax carbo, Little Black Cormorant, P.sulcirostris, large Pied Cormorant, P.varius (over 1000 pairs) and Little Pied Cormorant, P.melanoleucos. The nearby saltfields at Price have been identified as an area of international importance for shorebirds by Watkins (1993). The estuary also provides a significant nursery area for wide range of fish and crustaceans, including Yellow-eye Mullet, Tommy Ruff, Southern Sea Garfish, King George Whiting, School Whiting, and Southern Fiddler Ray. The Department of Environment, Heritage and Aboriginal Affairs is in the process of proclaiming the area as a Conservation Park. − − Clinton has been identified as a wetland of national importance (see ANCA 1996). Clinton Conservation Park is a mangrove/samphire estuary with subtidal seagrass meadows, and many large tidal channels, fringed by mangroves. The River Wakefield is the only major drainage channel in the area. The extensive tidal channels are important habitats for birds and marine fauna, particularly fish and crustaceans. The area has been identified as an area of international importance for shorebirds by Watkins (1993). Threatened species of waterbirds in the area include the Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), and part of the limited habitat of the Slender-billed Thornbill, Acanthiza iredalei rosinae (Sv). A total of 38 species of waterbirds have been recorded in the area: 11 are listed under international treaties. The Clinton Conservation Park is listed on the Register of the National Estate. Port Gawler and Buckland Park lake have been identified as a wetland of national importance (see ANCA 1996). Port Gawler consists of vast tidal flats and fringing mangrove forests, dissected by a multitude of tidal channels, creeks and the Gawler River. Port Gawler Conservation Park (434 ha) is a mangrove/samphire estuarine area with many large tidal channels fringed by mangroves. Port Gawler provides an important nursery area for commercial fish and crustacean species. A total of 13 species of marine fish have been recorded. Buckland Park lake is a large, ephemeral freshwater lake which was formed by damming the deltaic mouth of the Gawler River. The lake attracts an extremely wide variety of waterbirds, particularly waterfowl, that use the lake and associated swamps for feeding, breeding and roosting. The lake is the only substantial freshwater habitat on the Adelaide Plains and is also the single most important breeding habitat for waterfowl within the Adelaide region. Threatened species in the area include the saltmarsh plant, Halosarcia flabelliformis (Nv, Sv) and the following species of waterbirds: White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Freckled Duck, Stictonetta naevosa (Sv), Musk Duck, Biziura lobata (Sv), Little Egret, Egretta garzetta (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), Slender-billed Thornbill, Acanthiza iredalei rosinae (Sv), Australasian Shoveler, Anas rhynchotis (Sr), Baillon’s Crake, Porzana pusilla (Sr) and Spotless Crake, Porzana tabuensis (Sr). A total of 65 waterbirds have been recorded in the area: 16 are listed under international treaties. At Port Gawler there are well-established nesting colonies of Pied Cormorants, Phalacrocorax varius. Port Gawler is listed on the Register of the National Estate. − The coastal and marine wetlands of Barker Inlet and St Kilda (on the eastern shore of Gulf St Vincent) have been identified as wetlands of national importance (see ANCA 1996). The region encompasses the coastal waters, fringing mangroves, tidal creeks and adjoining wetlands and saltfields of the Barker Inlet, extending from St Kilda to Outer Harbour. The wetlands in the region are conserved in two aquatic reserves: the Barker Inlet – St Kilda Aquatic Reserve and the St Kilda - Chapman Creek Aquatic Reserve. Barker Inlet itself comprises the extensive coastal estuary of the Port Adelaide River, with two islands (Torrens Island, Garden Island). The inlet is dissected by several tidal and freshwater (and stormwater) creeks which drain into the eastern side of the inlet, ie. Swan Alley Creek (from the Little Para River), Chapman Creek, Broad Creek and North Arm Creek. The wetlands in the region represent the largest area of mangrove forests in Gulf St Vincent (Edyvane 1991) and a good example of coastal and marine wetlands in Gulf St Vincent, and is one of the few examples in close proximity to a major city in Australia. Page 174 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT The extensive coastal tidal floodplain in the region encompasses several major coastal habitat types include low-lying dunes and chenier ridges, supratidal samphire flats (which are covered by extremely high spring tides), intertidal mangrove woodlands (dominated by Avicennia marina); intertidal mud and sand flats, tidal channels and subtidal seagrass meadows (dominated by Eelgrass, Zostera muelleri and Garweed, Heterozostera tasmanica and Tapeweed, Posidonia). St Kilda - Chapman Creek Aquatic Reserve abuts the Barker Inlet Aquatic Reserve and predominantly protects the intertidal habitats from St Kilda to Chapman Creek. It is an important extension of the Barker Inlet habitat and has similar biological features. The variety of coastal habitats provide roosting, sheltering and feeding grounds for a large number of waterbirds and provide early spring to late summer refuge for many migratory waders (ANCA 1996). Threatened species in the area include the saltmarsh plants, Halosarcia flabelliformis (Nv, Sv) and Centrolepis cephaloformis (Sr) and 3 species of waterbirds: White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Little Egret, Egretta garzetta (Sv), Slender-billed Thornbill, Acanthiza iredalei rosinae (Sv). A total of 57 species of waterbirds have been recorded in the area: 12 are listed under international treaties. The area also provides significant breeding habitats for 18 species of waterbirds including, pelicans, cormorants, oystercatchers, gulls, terns, egrets and herons. The Port River mouth and the Penrice saltfields have been identified as areas of international importance for shorebirds by Watkins (1993). The inlet and adjoining mangrove creeks serve as important nursery areas for a number of commercial and recreationally important species of fish and crustaceans (see below), and are recognised feeding areas for the Common Dolphin, Delphinus delphis. Other marine mammals recorded in the region include the Leopard Seal, Hydrurga leptonyx, Blue Whale, Balaenopter musculus (Ne, Se) and Shortfinned Pilot Whale, Globicephala macrorhyncus (Sr) (ANCA 1996). − meadows in the region make a significant contribution to the primary production of the inlet. The algae and discarded seagrass leaves are a further component in the food web of the inlet. At high tide many fish, eg. Garfish, Whiting, Flounder and Mullet, may be observed feeding on polychaete worms, small crustaceans and molluscs on these intertidal flats while at low tide many wading birds are seen feeding in these same areas. The intertidal mudflats are an important decomposition area and the site of extensive detritus-based (drifting/decomposing plant matter) food chain. This is evident by the many worm mounds and crabs that may be observed feeding on the mudflats. At high tides these flats are important feeding areas for such fish species as Garfish, Flounder and Mullet. The narrow subtidal band of Tapeweed (Posidonia sp.) along the edge of the Barker Inlet channel provides shelter and food for many organisms. Other Areas of Recognised Conservation Significance − The Light River Delta is unique in this region as it has closely associated salt and freshwater wetland ecology. It is very rich in bird life and in plant species. It is a seasonal wetland. − Seacliff reef is widely recognised as one of best local dive spots in Adelaide, due to its abundance of fish and relatively shallow depth (Diving Industry Association of South Australia). Seacliff reef is a remnant shoreline, which runs parallel to the coast in a north-south direction, in 12-15m of water. The reef is home to a wide variety of marine life, particularly fish, including Leafy Sea Dragons and the greatest number of Blue Devils in the metropolitan area. The reef is listed as one of the best dive spots in South Australia, in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The Barker Inlet estuary represents the most significant nursery area for many species of important commercial and recreational marine fish species in Gulf St Vincent including Western King Prawns (Penaeus latisulcatus), King George Whiting (Sillaginodes punctatus), Yellow-Fin Whiting (Sillago schomburgkii), Garfish (Hyporhamphus melanochir), Yellow-Eye Mullet (Aldrichetta fosteri), Jumping Mullet (Liza argentea), Bream (Acanthopagrus butcheri) and Blue Swimming Crabs (Portunus pelagicus) (Jones 1984, McGlennon 1992). These seagrass Page 175 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT 1.2 Physical Geological Monuments − 2 2.1 Pine Point (from carpark north for 1 km): shore platform and cliffs. Significant features include an unconformity and Pre-Tertiary faulting. Pine Point Quarry is on the Register of the National Estate. The marine scalefish catch for this region (ie. Fishing Zones 35 and 36) represented 832,099 kg in 1995/96 and 692,894 kg in 1996/97(or 8.00% and 6.84% of the total catch for the marine scalefish fishery in South Australian waters). Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Port Adelaide 37: 1 Abalone, 9 Gulf St Vincent Western King Prawn, 2 Southern Rock Lobster, 6 Spencer Gulf Western King Prawn, 5 Southern Rock Lobster, experimental crab 1, 1 West Coast Prawn, 1 Abalone, 10 restricted marine scalefish − Port Clinton: 1 restricted marine scalefish, 3 unrestricted marine scalefish − Port Gawler: 1 restricted marine scalefish − Port Price: 1 restricted marine scalefish, 1 unrestricted marine scalefish − Port Wakefield: 2 restricted marine scalefish, 12 unrestricted marine scalefish − Port Parham: 1 unrestricted marine scalefish − Pine Point: 3 unrestricted marine scalefish OTHER VALUES Commercial Fisheries The main single species fishery in this biounit is the Western King Prawn. Trawling in the gulf begins from just south of Port Prime to the north east tip of Kangaroo Island. Trawling does not occur north of Ardrossan or Port Prime. The biounit is also one of the most significant fishing grounds for the marine scalefish industry in South Australia. There is no commercial harvesting of abalone in this biounit. Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours, respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). 2.2 There is currently no aquaculture in this region. The Gulf St Vincent/Fleurieu Aquaculture Management Plan (Berggy 1996) proposes limited aquaculture development in this region: Marine Scalefish Fisheries The Clinton Biounit represents a significant region for the marine scalefish industry in South Australia and comprises 2 major fishing zones: Fishing Zone 35 (northern waters) and 36 (southern waters). During 1995/96 and 1996/97, 135 and 102 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from this region (ie. Fishing Zones 35 and 36), respectively. License holders expended a total of 9065 and 7254 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. Aquaculture Upper Gulf St Vincent Policy Area − Upper Gulf North Management Zone (northern gulf waters, from Tiddy Widdy Beach to just north of Middle Beach) – zoned for limited aquaculture development. Licenses will be considered for a total of 40ha of algal culture in this zone. Licenses for other forms of aquaculture will not be considered. 37 Abalone and southern rock lobster are not caught in this bioregion - Port Adelaide is the registered home address for these licenses only. Page 176 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT − − Upper Gulf South Zone (southeastern gulf waters, from just north of Middle Beach to Outer Harbour) – zoned for recreational, fishing, and conservation values. Licenses will not be considered for aquaculture development in this zone. Upper Gulf Management Zone (waters offshore from Port Gawler) – zoned for subtidal aquaculture development. Licenses will be considered for a total of 40ha of aquaculture development in this zone, excluding the culture of Pacific Oysters. Tourism − Canoeing, dolphin education and ecointeraction tours of the Port River and Barker Inlet estuary. − The Barker Inlet estuary is a very popular area for recreational activities including fishing, boating, power boat racing, canoeing, water skiing and bird watching. − SCUBA diving: there are several popular wreck and reef dive sites in the metropolitan Adelaide region, including the Glenelg dredge (5-6kms west of Glenelg), Glenelg barge (5kms west of Glenelg), Glenelg tyre reef (5kms west of Glenelg), Macs Ground (reef 4.5kms west of Glenelg), Milkies reef (reef 4.5kms south west of Glenelg), Seacliff reef, `Leather Jacket Alley’ (2kms north west of Glenelg), `Broken Bottom’ (low reef 2kms north west of Glenelg), Grange tyre reef (4kms west of West Beach), `Norma’ shipwreck (4kms west of North Haven), `John Robb’ shipwreck (15kms west of North Haven). All are recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Metropolitan Adelaide Policy Area − Metropolitan Inshore Management Zone (inshore waters, within 2nm of the coast, from Outer Harbour to Sellicks Beach) – zoned for Blue Mussel spat collection. Licenses will be considered for a total of 10ha of Blue Mussel spat collection. Licenses for other forms of aquaculture will not be considered. − Metropolitan Offshore Management Zone (offshore waters, from 2nm to offshore boundary of policy area, from Outer Harbour to Sellicks Beach) – zoned for aquaculture development. Licenses will be considered for a total of 60ha of bivalve aquaculture (early growth stages). Licenses for other forms of aquaculture will not be considered. 2.3 Recreation and Tourism 2.4 − At St Kilda there is mangrove 1.7 km board walk and education/interpretative centre that is very popular with schools and universities. It is managed by the Salisbury City Council, with assistance from the SA National Parks and Wildlife Service. − Barker Inlet is a popular area for research into pollution, mangroves and fish ecology. Institutions that have used this area include the South Australian Department of Fisheries, The Flinders University of South Australia and The University of Adelaide, the Electricity Trust of South Australia, and the Engineering and Water Supply Department. − The Barker Inlet – St Kilda and adjacent salt fields region is a very popular region for bird watching and is regularly visited by overseas ornithologists and has become a bird observation area of interstate and international reknown (ANCA 1996). Fishing − − − Price: boat and jetty fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Blue Swimming Crab, Tommy Rough and Southern Calamari. St Kilda: boat and shore fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Snapper, Mulloway, Snook, Garfish, Blue Swimming Crab, Tommy Rough and Southern Calamari. Port Adelaide River: boat and shore fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Australian Salmon, Yelloweye Mullet, Snapper, Mulloway, Snook, Garfish, Blue Swimming Crab, Tommy Rough. Scientific Research and Education Page 177 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT − 2.5 The Star-of-the-Sea Primary School and Aquatic Centre, at Henley Beach, provides a range of school-based marine and coastal educational activities in the metropolitan Adelaide region. The centre offers a range of courses and educational activities on marine and coastal habitats and species, utilising the local environments of metropolitan Adelaide, and also hosts a wide range of marine aquaria for project work. Adjacent Land Use National and Conservation Parks − Clinton Conservation Park (1,951 ha) (Martin 1980). − Port Gawler Conservation Park (418 ha) (SANPWS 1983). − Torrens Island Conservation Park (79 ha). − Fort Glanville Conservation Park (4 ha): a historical conservation park associated with European settlement. Due to its close proximity to Adelaide, there are also several industries located on land immediately adjacent to the wetlands of the Barker Inlet estuary and the Port Adelaide River. A number of these industries discharge directly into adjacent waters. Major pollution inputs include, the Torrens Island Power Station, which discharges warm water into Barker Inlet, and the Port Adelaide Sewage Treatment Works, which discharges secondarily treated effluent into the Port Adelaide River. Further, this area also receives pollution from the Little Para River and `urban runoff’ from several stormwater drains which discharge into the estuary. Together, these pollutant inputs have resulted in the Port River estuary being one of the most diversely polluted estuaries in South Australia (Edyvane 1996). In recent years, the establishment of the Multi-Function Polis in the region, at Gillman and Dry Creek has seen the development of man-made wetland areas using stormwater runoff from adjacent areas. Klein Point is quarried for Tertiary limestone used in cement manufacture which is shipped to Port Adelaide. Urban Centres − Port Wakefield (population <250). Port Wakefield has a permanent coastal mooring facility for commercial and recreational craft. − Adelaide and its suburbs (population expected to be between 1.13 and 1.17 million by the turn of the century). Agriculture/Industry Much of the adjacent coastal land in this biounit is covered by coastal wetlands (ie. mangrove swamps and samphire flats). As such, there is generally little agricultural activity which occurs immediately adjacent to the coast. Despite this, considerable reclamation activity has occurred in this region, particularly for salt production. Extensive salt fields owned by Penrice Soda Products Pty Ltd occur adjacent to the mangroves and wetlands in the Barker Inlet-Port Gawler region. Salt production also occurs adjacent to mangroves at Port Price. The southern part of this biounit is occupied by the city of Adelaide, the largest centre of population in South Australia. Along the coastal metropolitan Adelaide region, 4 sewage treatment works discharge secondarily treated effluent into coastal waters (ie. Bolivar, Port Adelaide, Glenelg, Christies Beach). The Bolivar Sewerage Treatment Works is located north of metropolitan Adelaide (south of Port Gawler) and discharges secondarily treated effluent and sludge. In addition a number of diffuse sources of marine pollution occur via stormwater inputs from the Torrens River (which flows out to sea at Henley Beach) and Brown Hill and Sturt Creeks (which drain into the Patawalonga at Glenelg, which then flows into the sea). Other Uses Permanent coastal mooring facilities for commercial and recreational craft at St Kilda, Garden Island, North Arm, North Haven, Port Adelaide and environs and Patawalonga (Glenelg). − Department of Defence Firing Range near Port Parham. This is an area of prohibited public access (for both land, and sea). − Outer Harbour and Port Adelaide are major ports for international and national ships. Page 178 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT 2.6 Features Significant Cultural and Historical − `John Robb’ - the wreck sank during a storm in the outer shipping channel to Outer Harbour in 1910. The wreck is nearly completely broken up (apart from the bow) and is located 15kms west of North Haven in 18m of water. − `Grecian’ (1841-1850): a three-masted wooden barque which was wrecked in a storm at the entrance to Outer Harbour with the loss of one life. 3 CURRENT CONSERVATION STATUS OF THE CLINTON BIOUNIT Aboriginal − Tiddy Widdy beach (has been looted). European Shipwrecks − − − − − `Santiago’ (1856-1945): a three-masted iron barque, abandoned in the North Arm of the Port River. There are several wrecks and artificial reefs in the metropolitan Adelaide region which are also popular dive spots: Glenelg dredge - is an old suction dredge built in Holland in 1914 and sailed out to Australia in 1920. The dredge was used to dredge the Port River and Outer Harbour and was sunk in 1985 as an artificial reef. The wreck is located 5-6kms west of Glenelg in 20m of water. Glenelg barge - is a hopper barge used by the Glenelg dredge to take the silt dredged from the Port River. The barge was sunk in 1984 as an artificial reef. The wreck is located 5kms west of Glenelg in 20m of water. Glenelg tyre reef – is a reef composed of tyre tetrahedrons which was established in 1983. The artificial reef is located 500m south east of the Glenelg barge, 5kms west of Glenelg, in 18m of water. − Grange tyre reef - is a reef composed of tyre tetrahedrons which was established in the late 1970s. The artificial reef is located 4kms west of West Beach in 15m of water. − `Norma’ (1898-1907): a four-masted steel barque which was sunk by a collision with the `Ardencraig’ with the loss of one life in the main shipping channel of Outer Harbour in the early 1900s. As a shipping hazard the wreck was blown up by authorities, but the bow is still recognisable. The wreck is located 4kms west of North Haven in 16m of water. − − Marine Reserves St Kilda-Chapman Creek (870 ha) Barker Inlet-St Kilda (2,055 ha) − Marine Parks None − Netting Closures Price (within 1.1 nautical mile radius of Will Creek Light Beacon north of Mangrove Point and all waters of Will Creek and its tributaries). − Port Wakefield (within 100 metres of the dredged channel extending generally in a south-westerly direction from the mouth of the River Wakefield). − Outer Harbour and Port Adelaide River (those waters bounded by southern and northern revetment mounds at Outer Harbour including those enclosed by a line from the north eastern end of the northern revetment mound to the Section Bank pile beacon (Black Pole), to the Middle Ground outer beacon, to Point Grey on the northern tip of Torrens Island, then generally in a southerly direction contiguous with the western extremity of the mangroves on Torrens Island which includes all the waters of the Port Adelaide River and the North Arm as far as the Grand Trunkway Road Bridge. − Metropolitan beaches (all waters of Gulf Saint Vincent within 600 metres of high water mark between the seaward end of the southernmost Outer Harbour breakwater and the southern boundary of the Aldinga Aquatic Reserve. − Patawalonga Lake (all waters of the lake). Page 179 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – CLINTON BIOUNIT 4 AREAS OF HIGH CONSERVATION VALUE IN THE CLINTON BIOUNIT `Zanoni' Shipwreck − Light River - Port River Estuary 39 − Prime IUCN Conservation Values: cultural values, biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subjected to human-induced change), ecological (range of marine habitats-reefs, seagrass meadows, significant reef fish populations), economic (marine scalefish fisheries, tourism), social (cultural-shipwreck, shipwreck diving), practicality (insulation, compatibility-Historic Shipwreck). Wills Creek-Clinton Conservation Park 38 − Prime IUCN Conservation Values: biodiversity, aesthetics, rare and endangered species/habitats, social values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, most significant nursery in Gulf St Vincent for Western King Prawn, geological monument-Port Julia), ecological, (wide range of coastal marine wetlands and habitatsextensive seagrass meadows and mangrove forests, estuaries-Wills Creek, Shag Creek, Wakefield River, major nursery area and feeding area for fisheries in Gulf St VincentKing George Whiting, Garfish, Western King Prawn, Yellow-Eye Mullet, threatened waterbirds-Eastern Curlew, Fairy Tern, Whitebellied Sea-Eagle, breeding colonies of Pied Cormorants, Great Cormorants, Little Black Cormorants, Little Pied Cormorants, Little Terns, Caspian Terns), economic (marine scalefish fisheries, Western King Prawn, tourism), social (aesthetic values, recreation), national/international (international importance for shorebirds, Wetlands of National Importance-Wills Creek, Clinton Conservation Park, Register of the National Estate-Clinton Conservation Park, potential for listing as a RAMSAR site), practicality (insulation, accessibility, compatibility-adjacent to Wills Creek wetland, Clinton Conservation Park). Prime IUCN Conservation Values: biodiversity, education, social values, rare and endangered species/habitats (IUCN Category II). IUCN Identification Criteria: biogeographic (`geological monument', most extensive marine wetlands in Gulf St Vincent), ecological, (wide range of coastal marine wetlands and habitats, extensive and diverse coastal saltmarsh flats, estuaries-Light River, Gawler River, Chapman Creek, Port River, most significant fisheries nursery and feeding area in entire gulf-King George Whiting, Garfish, Yellow-fin Whiting, Yellow-Eye Mullet, Jumping Mullet, Bream, Blue Swimming Crab, most extensive mangrove forests and seagrass meadows in Gulf St Vincent, threatened waterbirds-White-bellied Sea Eagle, Cape Barren Goose, Little Egret, Fairy Tern, breeding colonies of Pied Cormorants, Caspian Terns, Australian Pelicans), economic (marine scalefish fisheries, Western King Prawn, tourism), social (education-St Kilda Mangrove Trail Interpretation Centre, extensive recreation, historic shipwrecks- `Santiago’, `Norma’, `John Robb’, `Grecian’'), scientific (fisheries research/monitoring-Barker Inlet), national (Wetlands of National Importance-Port Gawler and Buckland Park, Barker Inlet and St Kilda, Register of National Estate-Port Gawler Conservation Park, Conservation Park), practicality (insulation, accessibility, compatibility-adjacent to Port Gawler Conservation Park, Torrens Island Conservation Park, St Kilda-Chapman Creek Aquatic Reserve, Barker Inlet Aquatic Reserve). Glenelg Shipwrecks Prime IUCN Conservation Values: cultural values, biodiversity (IUCN Category III). IUCN Identification Criteria: ecological (seagrass meadows, significant reef fish populations), economic (marine scalefish fisheries, tourism), social (shipwrecks-Glenelg dredge, Glenelg barge, shipwreck diving), practicality (insulation, compatibility-Historic Shipwreck). 39 38 Mangrove areas between Port Clinton to Port Wakefield were nominated for declaration as Aquatic Reserves by the former South Australian Department of Fisheries in 1974, for fisheries management and conservation purposes (Wynne 1980). The region from Port Prime, south to, and including, Torrens Island, and also, the St Kilda-Chapman Creek and Barker Inlet Aquatic Reserves, is presently the subject of a multiple-use Marine Protected Area (draft Northern Adelaide Coastal Wetlands Background Paper). Page 180 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT XXII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE YANKALILLA BIOUNIT This biounit extends from Marino Rocks (just north of Hallett Cove) to Rapid Head and covers an area of 51,561 ha. It faces west into Gulf St Vincent. MARINE BIOGEOGRAPHY 1 − OCEANOGRAPHY Predominantly moderate wave energy environment with moderate to high wave energies during winter. Major Benthic Communities • 2 GEOLOGY AND GEOMORPHOLOGY40 COASTAL − In the Hallett Cove region, pre-Cambrian aged rocks form spectacular cliffs separating the Adelaide Plain from the Willunga Basin. There are several pocket beaches along the coast. In the Willunga region, large exposures of Tertiary marine sediments form low soft cliffs and headlands with numerous pocket beaches. A significant river outlet and estuary occurs at Onkaparinga. The southern end of the basin is bounded by further exposures of pre-Cambrian aged rocks (D. Fotheringham, pers.comm.) The long wide sandy beaches and high exposed cliffs in the metropolitan region that characterise the northern section of this biounit, give way to alternations of lower headlands and smaller bays. Small pocket beaches occur at intervals such as at Myponga and Normanville. • − 3 BIOLOGY Major Habitats − Major intertidal habitats in the region include mostly bays, rocky cliffs and platforms, and sandy beaches. Of the total inshore subtidal habitats mapped in the biounit (25,456 ha), sandy bottoms comprise 15,845 ha (62.2%), seagrass meadows comprise 7,646 ha (30.0%), and reefs comprise 1,966 ha (7.7%). Macroalgal Wave exposure increases from Aldinga Bay to Cape Jervis. On moderately exposed rocky shores and reefs in this region (eg. Port Noarlunga Reef, Aldinga Reef, Carrickalinga Head), shallow reef areas are dominated by Ecklonia radiata and species of Cystophora (C.siliquosa, C.subfarcinata, C.monilifera, C.moniliformis, C.expansa, C.brownii), and Sargassum (S.decipiens, S.fallax), with an understorey of Lobophora variegata, Caulerpa (C.racemosa and red algae. In more sheltered areas (eg. Rapid Bay), species such as Scaberia agardhii and Caulocystis ulvifera occur as sub-dominants with species of Sargassum (S.decipiens) and Cystophora (C.expansa, C.monilifera) and with an understorey of the prostrate brown algae, Lobophora variegata. Seagrasses Extensive seagrass meadows occur in this region, in Aldinga Bay and Yankalilla Bay, and also in shallow, sandy, offshore areas adjacent to reefs and boulder fields. Sandy sediments are commonly colonised by species of Posidonia (P.sinuosa, P.angustifolia), Amphibolis antarctica and Halophila australis, which often occurs adjacent to reef communities and in deep water (ie. 20m). Patches of Posidonia coricea also occur in the shallow waters of Aldinga Bay. 40 From Fleurieu Coast Protection District Study Report (Llewellyn-Davies et al. 1977). Page 181 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT Coastal and Offshore Islands (or Reefs) − Marino Rocks is a wide intertidal platform with large boulders that is exposed to moderately high wave energy. Barnacles, mussels, various gastropods and sea anemones are found here. − Port Noarlunga Reef. − Aldinga Reef. − `Five mile reef' (offshore from Wirinna). − The estuary itself extends 16 km inland from the mouth, and is protected as the Onkaparinga Conservation Park (1 587 ha) and the Onkaparinga Estuary Aquatic Reserve. It is comprised of three major habitat types: (i) the upper tidal reaches of the river, (ii) the lagoon/floodplain habitat in the lower reaches of the estuary, and (iii) the remnant sand dunes near the river mouth. The floodplain of the Onkaparinga Estuary is characterised by salt-tolerant samphires and areas of sandy marine and estuarine mudflats which are in part colonised by Eelgrass, Zostera muelleri. The seagrass habitat in turn provides food and/or shelter for the fishes which frequent the lower reaches of the river. The estuary is a recognised spawning area for Black Bream, Acanthopagrus butcheri, and a nursery area for Yellow-Eye Mullet Aldrichetta fosteri. As total of 23 species of fish have been recorded in the estuary, including Yellow-Eye Mullet, Jumping Mullet, Liza argentea, Black Bream, and Congolli, Pseudaphritis urvilli, Australia Salmon, Arripis truttacea, Southern Sea Garfish, Hyporhampus melanochir, and Bridled Goby, Gobius bifrenatus. Large birds such as White-Faced Heron, Egretta novaehollandiae, Great Egrets, Ardea alba, and Royal Spoonbills, Platalea regia, commonly feed in the shallows and swamp areas on the diverse animal life consisting mainly of polychaete worms and crustaceans (small crabs etc.). Threatened species of waterbirds recorded in the area include the Musk Duck, Biziura lobata (Sv), Cape Barren Goose, Cereops novaehollandiae (Sv), Latham’s Snipe, Gallinago hardwickii (Sv) and the Australasian Shoveler, Anas rhynchotis (Sr). A total of 50 species of waterbird have been recorded in the area: 7 are listed under international treaties. Adjacent to the estuary there is a recreation park, managed by the South Australian National Parks and Wildlife Service. − The Onkaparinga River is tidal as far as the township of Old Noarlunga. During the summer months the river receives minimal freshwater flow and deposits of sand inshore close the mouth of the river, creating a lagoon in the lower portion of the estuary. Hundreds of years ago the former mouth of the river was further north and its exit was through "The Gap" of Port Noarlunga Reef. The sand dunes near the river mouth are sparsely vegetated with introduced species, planted as part of a dune stabilisation program, and provide protection to the lagoon/floodplain to the east of the dunes. Rivers and Estuaries − Onkaparinga Estuary (which flows out to sea at Port Noarlunga). − Pedler Creek (which flows out to sea at the Moana Sands Conservation Park). − Myponga River. − Yankalilla River. − Bungala River. − Carrickalinga Creek. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance − The Onkaparinga Estuary (60 ha) comprises an environment which is not common elsewhere in Australia. It represents the largest estuary between the Glenelg River in south-western Victoria and Blackwood River in south-western Western Australia, and the third largest permanent river in South Australia (after the Murray and Port Adelaide River). The coastal samphire community within the reserve is the only example of this community type south of Adelaide along the eastern shores of Gulf St.Vincent. Page 182 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT Within the pools on the shoreward edge of the reef, Ulva sp. (green Sea Lettuce), and patches of seagrass occur, including Heterozostera (Eelgrass) or Zostera muelleri (Garweed). Small rock crabs and hermit crabs (Paguristes frontalis) are also found. On the outer intertidal edge of the reef is a band of red turf algae, the most common species present is Gelidium pusillum. Off the edge of the reef to about 10 m deep, kelp plants (Ecklonia radiata), about one metre high, are most common. In rocky areas Cystophora spp. and Sargassum spp. occur. Some of the sandy areas between the rocks and to the north and west of the reef support the seagrasses, Zostera muelleri (Garweed), Amphibolis antarctica (Wireweed) and Posidonia sinuosa (Tapeweed). There are numerous reef fish, shells, sponges, hydroids and sea squirts. Some 1200 m offshore, north-west from Snapper Point, there is a spectacular under water cliff (the "drop-off") of about 10 m down to 21m. Here gorgonian corals, numerous sponges and many reef fish may be observed. Further away from the reef, where the seafloor is sandy, the occasional scallop and clump of stalked orange red ascidian (Pyura spinifera) are found. Other Areas of Recognised Conservation Significance − − Port Noarlunga Reef (240 ha) which is part of the Onkaparinga Estuary Aquatic Reserve. The reef is formed from a consolidated Pleistocene sand dune, is 1.6 km long and lies some 400m offshore. It is separated into two reefs by a channel called "The Gap". A jetty runs out from the shore almost to the reef, so swimming is the only access to the reeftop, which may be explored at low tide. On the flat reeftop is an algal-mussel community dominated by the small black mussel, Modiolus pulex, and an assemblage of turf algae including species of Corallina, Gelidium and Codium capitulatum. Below the low water mark, kelp plants (Ecklonia radiata) about one metre high, dominate the outer reef slope. Other large brown algae, such as Cystophora moniliformis, C.subfarcinata and C.monilifera, and Sargassum species are common on the calmer, inside edge of the reef. Beneath the canopy of these large brown algae, smaller green, brown and red seaweeds form an understorey. In addition to the abundant plant life, numerous sedentary organisms such as bryozoans, sponges, hydroids, ascidians (Sea-Squirts) and molluscs, including the Blacklip Abalone, (Haliotis rubra) and Pheasant shells (Phasianella spp.), also form part of the reef marine community. A rich sponge-hydroid community may be seen at the southern end of the northern reef. Many species of reef fish including Magpie Perch, Scalyfin, Leatherjackets, Wrasses, Herring Cale, Coral Fish, Tommy Ruff, and Salmon Trout may also be seen near the reef. Aldinga Reef Aquatic Reserve (505 ha) is a large intertidal platform and reef complex. The intertidal platform consists of tertiary limestone that extends approximately 500 m offshore. The reef complex extends some 1,200 m offshore from Snapper Point where, at the seaward edge of the reef, there is a spectacular 'drop-off' with a precipitous underwater cliff of about 10 m. The cliff and overhangs are extremely rich in marine life, particularly sponges. Locally endangered species include: Gorgonia (Melithaea species) and Blue Groper (Achoerodus gouldii). The most common organism of the northern reef flat is the brown alga, Hormosira banksii (or Sea Grape). The southern section of the intertidal reef provides more sandy and rock pool areas and is colonised by a larger variety of marine plants including H. banksii, and the brown alga, Caulocystis uvifera. − Yankalilla Bay, is a large shallow, seagrassdominated embayment, which extends from Carrackalinga Head to Rapid Head. The bay contains the most extensive meadows of seagrass of any area south of metropolitan Adelaide, along the eastern shores of Gulf St Vincent. Within the bay, the relatively unspoilt isolated shallow, reef areas and seagrass meadows are also home to a wide range of fauna and flora, including rare fish species, such as the Leafy Sea Dragon, Phycodurus eques and species such as Blue Groper, which have been heavily reduced in many parts of the gulf. In particular, reef areas with subtidal boulders and rocks around Second Valley (eg. `Lasseter’s reef’), Rapid Head, Carrickalinga and Normanville, although not formally documented, are known to be rich in marine flora and fauna, and rare or uncommon fish species. Lasseter’s reef, in Second Valley, and Rapid Head are popular dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The 50m dome-shaped reef is home to a wide range of marine life, including Leafy Sea Dragons, and is very exposed. Page 183 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT − 1.2 Further offshore, `Five mile reef' is a popular place for fishers and divers. Fish observed here include reef fish such Harlequin, Boarfish, Blue Groper and the Blue Devil, species which have generally disappeared from shallow offshore reef areas closer to metropolitan Adelaide Physical − 2 2.1 Geological Monuments − Hallett Cove: Palaeozoic glaciation and type section in Waterfall Creek. The adjacent Hallett Cove Conservation Park is on the Register of the National Estate. − O'Sullivan Beach: glacial dropstone Precambrian Reynella Siltstone. in − Witton Bluff, South Bank: Tertiary beds. − Onkaparinga Mouth-Seaford: Tertiary beds (reference sections). − Maslin Bay-Aldinga Bay: Tertiary Type sections in the coastal cliffs. The area is also on the Register of the National Estate. − Sellicks Beach: Willunga Fault. − Myponga Beach: Sellick Hill Limestone and Fork Tree Limestone. Part of the area is also on the Register of National Estate, while the whole area is on the State List. − Carrickalinga Head: Heatherdale Shale and Type Locality for Carrickalinga Head Formation. This area is also on the Register of the National Estate. − Normanville Sand Dunes: recent dunes along coast. This area is also on the Register of the National Estate. − South Yankalilla Beach, Little Gorge Area: Unconformity Precambrian Inlier with Adelaidean. − Second Valley Harbour: coastal cliffs containing structures in Precambrian marbles and slates. This area is also on the State Heritage List. Cape Jervis: type section for Cape Jervis Beds, and Permian Glaciation. This area is also on the State Heritage List and the Register of the National Estate. OTHER VALUES Commercial Fisheries The major single species fishery that operates in this northern area is the Western King Prawn. Boats trawl in the gulf sometimes within a few kilometres of the shore. There is also a marine scalefish fishery, especially netting. Commercial harvesting of abalone in this region is negligible. Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours, respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster This biounit encompasses 2 fishing zones: Fishing Zone 43 and 44. No lobsters were recorded in 1995/96 and 1996/97 off the southern metropolitan coast, in the northern section of this biounit (ie. Fishing Zone 43). However, lobster fishing is present in the southern section of this biounit which encompass the waters of the southern Fleurieu Peninsula and Backstairs Passage (and also, north western Kangaroo Island) (ie. Fishing Zone 44). In 1995/96 and 1996/97 a total of 8 and 6 licensed operators fished in this region (ie. Fishing Zone 44), catching approximately 7,036 and 5,390 kg of lobsters, respectively (or 0.14% and 0.11% of the total catch for Southern Rock Lobster in South Australian waters). Page 184 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT The major single species fisheries that operates in this southern area is Western King Prawn. Abalone There is negligible commercial harvesting of Greenlip Abalone in this biounit, (ie. MapCode 25A-D, Yankalilla Bay to Port Elliot, including Backstairs Passage and the Pages). In 1995/96 a total of 3498 kg of Blacklip was harvested within this region, which represented 8.3% of the total Blacklip Central Zone catch (or 0.76% of the total catch for Blacklip in South Australian waters). No Blacklip were harvested in this region in 1994/95. Marine Scalefish Fisheries The Yankalilla Biounit encompasses 2 fishing zones: Fishing Zone 43 and 44. During 1995/96 and 1996/97, 26 and 17 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the northern section of this biounit (ie. Fishing Zone 43), respectively. License holders expended approximately 733 and 720 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 43) represented 29,984 kg in 1995/96 and 40372 kg in 1996/97(or 0.29% and 0.39% of the total catch for the marine scalefish fishery in South Australian waters). In the southern Fleurieu and Backstairs Passage region, (ie. Fishing Zone 44), a total of 47 and 37 licensed operators fished 2,496 and 2,126 days in this region in 1995/96 and 1996/97, catching approximately 171,288 and 129,167 kg of lobsters, respectively (or 1.65% and 1.27% of the total catch for the marine scalefish fishery in South Australian waters). At Cape Jervis there are 10-15 full time line fishers (hand and long line). Main species caught are Southern Calamari (Sepioteuthis australis) over seagrass beds, and Snapper (Pagrus auratus) between 50m and 10m. Beach seining occurs on sandy beaches adjacent Cape Jervis for Salmon and Mullet. Backstairs Passage has an active hand/long line snapper industry. Southern Calamari is taken by jig nearer to Cape Jervis. Some Garfish is also taken here. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − 2.2 Port Willunga: 1 unrestricted marine scalefish − Glenelg: 1 unrestricted marine scalefish − Port Noarlunga: scalefish 1 unrestricted Aquaculture There is currently no aquaculture development in this region. The Gulf St Vincent/Fleurieu Aquaculture Management Plan (Berggy 1996) proposes limited aquaculture development in this region: Fleurieu Policy Area − West Fleurieu Management Zone (coastal waters, within 3nm of the coast, from Sellicks Beach, south to Cape Jervis, excluding Rapid Bay) – zoned for limited aquaculture development. Licenses will be considered for a total of 30ha of aquaculture development in this zone, excluding the culture of Pacific Oysters. − Rapid Bay Aquaculture Zone (coastal waters of Rapid Bay) – zoned for aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development in this zone. − East Fleurieu Zone (coastal waters, within 3nm of the coast, from Cape Jervis to the Murray Mouth) – zoned to protect tourism, recreation and conservation values. Licenses will not be considered for aquaculture development in this zone. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Cape Jervis: 5 restricted marine scalefish. marine − Normanville: 2 unrestricted marine scalefish − O'Sullivan's Beach: 2 unrestricted marine scalefish Page 185 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT 2.3 Recreation and Tourism − Myponga: boat, rock and river fishing. Major species: King George Whiting, Black Bream, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − There are three artificial reefs located at Glenelg (dredge, suction barge and tyre modules), one at Grange (tyre modules), and one at Port Noarlunga (tyre modules). − Normanville, Carrickalinga: boat, beach and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Second Valley: boat, jetty and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Rapid Bay: jetty and boat fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Garfish, Yellowtail Kingfish, Tommy Rough, Trevally, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − Cape Jervis: jetty, boat and rock fishing. Major species: King George Whiting, Australian Salmon, Snapper, Snook, Garfish, Bluefin Tuna, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. Fishing − − Because of its proximity to Adelaide and the coastal suburbs, this entire biounit is very popular for recreational fishing and is subject to intense use. Metropolitan coastline: boat, shore and jetty fishing (Largs Bay, Semaphore, Grange, Henley Beach, Glenelg, Brighton, Port Noarlunga). Major species: King George Whiting, Yellowfin whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Garfish, Blue Swimming Crab and Tommy Rough. − O'Sullivan Beach ramp: boat, beach and rock (breakwater) fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Silver Drummer and Southern Calamari. − Onkaparinga River: river and shore fishing. Major species: Yellowfin whiting, Black Bream, Yelloweye Mullet, Mulloway and Garfish. − Moana: boat and beach fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. − − Aldinga Beach: boat and beach fishing. Major species: King George Whiting, Sand Flathead, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Toothbrush Leatherjacket, Silver Drummer and Southern Calamari. Sellicks Beach: boat, shore and wharf fishing. Major species: King George Whiting, Yellowfin Whiting, Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Garfish, Blue Swimming Crab and Tommy Rough. Tourism − The metropolitan coast is the main swimming and boating area for Adelaide residents. Maslins Beach, south of Adelaide, has a section for nudist bathing which has proven to be very popular. Page 186 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT − SCUBA diving: there are several popular dive spots in the southern metropolitan Adelaide region and Fleurieu Peninsula. Port Noarlunga reef, Noarlunga tyre reef, the `Lumb’, the Stanvac barges, the Aldinga dropoff, Aldinga Pinnacles, Lasseters reef (Second Valley), Rapid Bay jetty, Rapid Head, the Bluff (Victor Harbour), West Island, and Blowhole Creek, are all recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). The dive at Rapid Bay jetty has been described by Reg Lipson as one the best jetty dives in Australia. Both Rapid Bay and Second Valley jetties are used an open water dive training sites. − Port Noarlunga Reef and the Onkaparinga estuary Aquatic Reserve is one of South Australia’s most intensively used and best known Aquatic Reserves, with over 170 000 visitors each year (Sutherland 1987) and an estimated 6000 SCUBA divers over summer (Papple 1990). − Onkaparinga estuary: fishing, canoeing, picnicking, bushwalking, bird watching and swimming. − Myponga: boating, fishing, holiday shacks, boat ramp, hang-gliding. − Normanville/Carrickalinga: jetty boating, swimming, SCUBA diving, 2.4 Scientific Research and Education − Port Noarlunga reef is used by schools, tertiary institutions and SCUBA diving clubs for education in the marine environment. It is a popular training place for new divers and snorkellers, with an estimated 6000 SCUBA divers annually over the summer period (Papple 1990). In 1994, the Port Noarlunga reef underwater interpretation trail was established on the north reef of Port Noarlunga, to raise community awareness of temperate reef environments and marine life (see Andrews & Edyvane 1996). The trail, the first of it’s kind in South Australia, was established by the SA Research and Development Institute, in consultation with the local community. The 800m trail consists of 12 underwater concrete trail markers (with educational plaques) and runs south from the Noarlunga jetty, along the shoreward edge of North reef, through the Gap, and then north along the outside of the reef. Each plaque provides information on the reef ecosystem and also, the reef inhabitants. − Port Noarlunga Primary School and Aquatic Centre plays a major role in school-based marine and coastal educational activities within the Port Noarlunga Reef and Onkaparinga Estuary Aquatic Reserve. The centre offers a wide range of outdoor activities, including snorkelling, sailing and kayaking. − Aldinga Reef is also used by many metropolitan schools and institutions for marine education activities. fishing, − Wirrina tourist resort, camping. − Lady Bay: scenic point, diving offshore at `5 mile reef'. − Second Valley: jetty fishing, boating, camping, diving, hang-gliding. This is considered a particularly spectacular scenic area. − Hallett Cove Conservation Park (51 ha). − Onkaparinga River Recreation Park (285ha) − Rapid Bay: jetty fishing, diving, camping, boating. − Onkaparinga River National Park (1,332 ha). − Cape Jervis: fishing, boating, hang gliding, ferry departures for Kangaroo Island, SCUBA diving. − Moana Sands Conservation Park (21 ha). − Aldinga Scrub Conservation Park (239 ha): preserves a significant remnant of the natural habitat that once occurred all along the southern Adelaide coastline. 2.5 Adjacent Land Use National and Conservation Parks Page 187 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT European Agriculture/Industry − − Most coastal land in this biounit is used for housing or holiday shacks. Some agricultural land occurs further south past Port Noarlunga. Very little uncleared or undeveloped land remains in this biounit. There is an oil refinery at Port Stanvac with deep port facilities. • Pollution sources: − Port Stanvac Refinery ballast water discharge − O'Sullivan Beach sewage effluent outfall − Mixed farming along the coast. − At Rapid Bay limestone mining occurs. • Pollution sources: − Rapid bay jetty/quarry − River Bungala outlet − Myponga river outlet Urban Centres − No major urban centres occur along this biounit. However, there are several small coastal centres with populations of less than 200 persons. These include, Myponga, Carrickalinga, Lady Bay, Second Valley, Rapid Bay and Normanville. These areas are predominantly used as holiday areas and consist primarily of beach houses and shacks. 2.6 Features Significant Cultural and Historical Shipwrecks − `Tigress’ (1840-1848): a two-masted wooden snow which was swept onto a reef during a storm, 2 kilometres south of the Onkaparinga River with 2 lives lost. − `Star of Greece’ (1868-1888): a three-masted iron ship that was blown ashore near Port Willunga during a storm, with 18 crew members killed. − There are also several artificial reefs in the area, including: the Noarlunga tyre reef (located 2.5kms west of the Noarlunga jetty in 20m of water); the `Lumb’ (a tug sunk in 1994 as a dive site, 20m west of the Noarlunga tyre reef); and the Stanvac barges (3 barges sunk approximately 5kms west of the Port Stanvac oil refinery). All are recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). 3 CURRENT CONSERVATION STATUS OF THE YANKALILLA BIOUNIT − Marine Reserves Port Noarlunga Reef & Onkaparinga Estuary (300 ha) − Aldinga Reef (505 ha) − Marine Parks None − Aboriginal The Kaurna people lived in this region and regularly migrated to the coast to fish and collect. Artefacts and in some instances, human remains, have been found at various locations along the coast, especially Sellicks Beach, Aldinga, Onkaparinga and Hallett Cove. A register of important sites is kept by the Aboriginal Heritage Branch of the Department of Environment and Planning. For confidentiality, these sites are not available for publication. − Netting Closures Metropolitan beaches (all waters of Gulf Saint Vincent within 600 metres of high water mark between the seaward end of the southernmost Outer Harbor breakwater and the southern boundary of the Aldinga Aquatic Reserve). Onkaparinga River (all waters of the River). Page 188 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – YANKALILLA BIOUNIT marine wetlands and habitats, seagrass meadows, reefs, estuaries-Myponga River, major fisheries-King George Whiting, Garfish, Calamari), economic (marine scalefish fisheries, tourism), social (recreation, shipwrecks-`Star of Greece), national (potential for listing on Register of National Estate), practicality (insulation, accessibility, compatibility-adjacent to Aldinga Scrub Conservation Park, Aldinga Aquatic Reserve ). 4 AREAS OF HIGH CONSERVATION VALUE IN THE YANKALILLA BIOUNIT Onkaparinga Estuary-Moana − Prime IUCN Conservation Values: education, biodiversity, social values (IUCN Category II). IUCN Identification Criteria: biogeographic (`geological monuments'-Witton Bluff, Onkaparinga Mouth-Seaford), ecological (range of coastal marine habitats, estuariesOnkaparinga River, Pedler Creek, reefs, seagrass meadows, major fisheries-King George Whiting, Garfish, Western King Prawn, breeding colonies of White-faced Herons, Egrets, Spoonbills), economic (marine scalefish fisheries, tourism), social (recreation, education-Port Noarlunga Primary School and Aquatic Centre, shipwrecks-`Tigress', aboriginal heritage area-Moana Sands), national (Wetland of National ImportanceOnkaparinga Estuary, nominated for listing on Register of National Estate), practicality (insulation, accessibility, compatibility-adjacent to Port Noarlunga and Onkaparinga Aquatic Reserve, Moana Sands Conservation Park). Aldinga Bay-Myoponga Estuary − Prime IUCN Conservation Values: biodiversity, education, social values (IUCN Category II). IUCN Identification Criteria: biogeographic (rare remnant of coastal vegetation along southern metropolitan Adelaide coastline, `geological monuments'Maslin Bay-Aldinga Bay, Sellicks Beach, Myponga Beach), ecological, (range of coastal Yankalilla Bay − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, social values (IUCN Category II). IUCN Identification Criteria: biogeographic (largest intact seagrass meadows along the metropolitan and Fleurieu Peninsula coastline, `geological monuments'Carrickalinga Head, Normanville Sand Dunes, South Yankalilla Beach, Second Valley Harbour), ecological, (wide range of coastal marine wetlands and habitats, extensive seagrass meadows, reefs-5-mile reef, Lasseter’s reef, estuaries-Bungala River, Yankalilla River, Carrickalinga Creek, reef fish populations, `endangered' Leafy Sea Dragon), economic (marine scalefish fisheries-King George Whiting, Calamari, Snapper, tourism), social (recreation, SCUBA diving), national (potential for listing on Register of National Estate), practicality (accessibility). Page 189 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT XXIII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE ENCOUNTER BIOUNIT This biounit extends from Rapid Head on the southwest Fleurieu Peninsula, to the Murray Mouth, and covers an area of 39,389 ha and a coastal distance of approximately 100 km. The waters of Backstairs Passage and the Pages offshore islands are classified within the Backstairs Biounit (see Kangaroo Island Coast). MARINE BIOGEOGRAPHY 1 3 Major Inshore Habitats OCEANOGRAPHY The coast from the Murray Mouth westward to Cape Jervis, increases from low wave energy to high energy. 2 GEOLOGY AND GEOMORPHOLOGY 41 BIOLOGY − Major intertidal habitats in the region include mostly rocky shores, sandy beaches and bays (Encounter Bay). − Of the total inshore subtidal habitats mapped in the biounit (9,439 ha), reefs comprise 5 452 ha (57.8%), sandy bottoms comprise 3 482 ha (36.9%), and seagrass meadows comprise 505 ha (5.4%). COASTAL From Cape Jervis to Rosetta Head there are spectacular steep cliffs, with direct exposure to the open waters of the Southern Ocean. At Rosetta Head the coastal morphology changes from cliffs to long sweeping beaches backed by dunes and interspersed at the western end by the granite outcrops of Rosetta Head itself, Granite Island and Freeman Nob. Granitic rocks also form rounded hills on promontories and offshore islands such as Wright Island, West Island and Seal Island. At Tunkalilla Beach, Waitpinga Beach, Victor Harbour and near Middleton, older Quaternary deposits of high level alluvium, outwash gravels, and laterised and kunkarised surface deposits form eroding cliffs three metres high exposed beneath recent sands. Tunkalilla, Parsons and Waitpinga Beaches are all high energy beaches backed by steep hills. The Inman and the Hindmarsh Rivers open to the sea only by flood waters and high tides, creating lagoons behind the beaches otherwise. The type section of the Kanmantoo Group of rocks is recorded along this stretch of coast. Major Benthic Communities • − Macroalgal The rocky shores and reefs of the south coast of Fleurieu Peninsula, east of Cape Jervis, generally experience greater wave exposure and strong tidal currents (through Backstairs Passage). On these exposed shore and reefs (eg. Porpoise Head, Tunkalilla, Newland Head, The Pages), reef areas are dominated by mixed sponges, hydroids, ascidians and bryozoans and large brown algae (ie. Scytothalia dorycarpa, Carpoglossum confluens, Ecklonia radiata, Seirococcus axillaris, Acrocarpia paniculata, Carpopeltis) with species of Cystophora (C.moniliformis, C.retorta) and species of Sargassum (S.sonderi, S.paradoxum) as sub-dominants, with an understorey of red algae (ie. Phacelocarpus, Plocamium, Rhodophyllis) and coralline algae (eg. Haliptilon, Metagoniolithon). 41 From Fleurieu Coast Protection District Study Report (Llewellyn-Davies et al. 1977). Page 190 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT • Seagrasses − Seagrass meadows are sparse in this region and are restricted to the sheltered embayments of Encounter Bay. Sandy sediments are commonly colonised by species of Posidonia (P.sinuosa, P.angustifolia), Amphibolis antarctica and Halophila australis, which often occurs adjacent to reef communities and in deep water (ie. 20m). invertebrates, a rich diversity of invertebrate species such as hydroids, bryozoans, ascidians, seastars and brittlestars, chitons, anenomes, gastropods and other molluscs, and crustaceans. (Shepherd & Watson 1970, Kangas & Shepherd 1984). The Encounter Bay region also contains highly abundant and diverse assemblages of high marine animals, such as ray and skate species, a variety of shark species (gummy, school, whiskery, bronze whalers), economically important molluscs such as Greenlip and Blacklip Abalone and the Goolwa Cockle (Baker & Edyvane 1996). Importantly, Encounter Bay also provides refuge for several rare, uncommon, and.or endangered species, such as the Southern Right Whale; the Australian Sea Lion; species of Sygnathids (ie Leafy and Weedy Seadragons, Pipefishes and Seahorses); the unusual octopus Argonauta nodosa, which creates the "paper nautilus" egg cases; a diversity of pycnogonid (sea spider) species, and has very diverse and dense articulated bryozoan communities (Baker & Edyvan 1996, S Shepherd SARDI pers.comm.). The Zostera beds in the region, particularly around Granite and West Islands, are also the only known location for a number of rare species of hemichordates (S Shepherd, SARDI pers.comm.). A rare phototrophic sponge species, Cymbastela sp., has been found in the sheltered subtidal habitats off West, Wright and Seal Islands and along the oceanic coast of Victor Harbor (Cheshire et al 1995). Rivers and Estuaries − Tent Rock Creek (Deep Creek Conservation Park). − Inman River (Victor Harbour). − Hindmarsh Harbour). River (north-east of Victor Coastal and Offshore Islands (or Reefs) − Granite Island, Wright Island, West Island, Seal Island and Pullen Island (Encounter Bay). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological − The globally protected endangered Southern Right Whale (Eubalaena australis) annually visits the Encounter Bay region during the autumn to mid spring months for mating, calving and rearing young, and can easily be seen close to shore. During the 1980s and 1990s there has been an increase in the number of whale sightings around Middleton, Victor Harbour and the coastline to the west of Encounter Bay. Apart from the Great Australian Bight, the Encounter Bay region is the most significant area in South Australia for migrant whales (Baker & Edyvane 1996). − Although the coastal sites along southern Fleurieu Peninsula are generally areas of low benthic floral diversity, the outer islands of Encounter Bay (ie Grantie, Wright, West, Seal and Pullen Islands) and Rosetta Head, display high algal diversity, with over 200 species recorded, including diverse red algal assemblages (Shepherd & Womersley 1970). Associated with these macroalgal communities are a diverse rang eof fish and − Marine life surrounding West Island is presently protected within the West Island Aquatic Reserve, which comprises approximately 84 ha. The reserve was established primarily for the protection of the marine benthic organisms around the island for long term ecological studies. The island itself is located 800 metres offshore at the north western end of Encounter Bay. As such, it’s accessibility has made it a popular research site for many marine biological studies. Major habitat types include, submarine cliffs, crevices and caverns, sandy and rocky seabed areas. The general features of the algal vegetation change markedly around the island passing from rough to more sheltered coasts. Three habitat types have been recognised: the rough water southern and western coasts; the moderately rough water sections on the eastern and northern shores; and the semi-sheltered section of Abalone Cove. To the lee of the island, extensive beds of seagrasses are present. Page 191 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT − − A number of bird species that have been recorded from the Encounter Bay region are listed as vulnerable or rare for the State, but only two of these are regularly seen – the Hooded Plover (Thinornis rubricollis) and the Fairy Tern (Sterna nereis). Hooded Plovers are regarded as nationally rare and vulnerable in South Australia, while Fairy Terns are regarded as rare at both levels (Garnett 1992). West Island and Granite Island support rich birdlife including large and important sites for breeding colonies of sea birds including, Little Penguins (Eudyptula minor), Silver Gulls, Crested Terns, Caspian Terns and Fairy Terns. Up to 50 pairs of Fairy Terns nested irregularly on Wright Island and West Island in the 1960s and in 1975-1976, but although one or two birds are seen regularly in the bay, there have been no further breeding records in the past 20 years. Hooded Plovers are seen in small numbers on sandy beaches in the region and breed nearby. Rosetta Head also has a population of Little Penguins. Birdlife is presently protected within the West Island Conservation Park, which includes Seal Island. The park is also on the Register of the National Estate. Granite Island has a Recreation Park, and is, likewise, on the Register of the National Estate. Encounter Bay appears, on the limited data available, to be one of the most signficant locations in the State for both, the Leafy Seadragon (Phycodurus eques) and the Weedy Seadragon (Phyllopteryx taeniolatus), which are listed on the IUCN Red List as data deficient (Hudson & Mace 1996). Leafy and Weedy Sea Dragons are highly ornate species of sea horse which are camouflaged to resemble the seaweeds and seagrasses in which they hide. They are considered to be highly unusual and beautiful creatures and are currently fully protected. Sea dragons are generally associated with the algal communities at West Island and Rosetta Head (ie the Bluff) and also, around the rocky areas of Encounter Bay. Encounter Bay also supports populations of other threatened species of the Family Sygnathidae (ie seahorse, pipehorse (Solegnathus robustus) and the Short-headed Seahorse (Hippocampus breviceps). The former two are rated as vulnerable and the latter as data deficient on the IUCN Red List (Hudson & Mace 1996). − Although there are no major colonies of seals in this region, sightings are made of the Australian Sea Lion (Neophoca cinerea) and Australian Fur Seal (Arctocephallus pusillis), and it is possible that they are returning to this area. For instance, Australian Fur Seals appear to be returning to Seal Rock. Although the coastal sites along southern Fleurieu Peninsula are generally areas of low benthic floral diversity, the outer islands of Encounter Bay display high algal diversity, with over 200 species recorded, including diverse red algal assemblages (Shepherd & Womersley 1970). These islands (Granite, Wright, West, Seal and Pullen Islands) also contain subtidal habitats which contain a rich diversity of invertebrate species such as hydroids, bryozoans, ascidians, seastars and brittlestars, chitons, anenomes, gastropods and other molluscs, and crustaceans. (Shepherd & Watson 1970, Kangas & Shepherd 1984). The Encounter Bay region also contains highly abundant and diverse assemblages of higher marine animals, such as ray and skate species, a variety of shark species (Gummy, school, whiskery, bronze whalers), economically important molluscs such as Greenlip and Blacklip Abalone and the Goolwa Cockle (Baker & Edyvane 1996). Importantly, Encounter Bay also provides refuge for several rate, uncommon, and/or endangered species, such as the Souther Right Whale; the Australian Sea Lion; species of Sygnathids (ie Leafy and Weedy Seadragons, Pipefishes and Seahorses); rare species of hemichordate; the unusual octopus Argonauta nodosa, which creates the “paper nautilus” egg cases; a diversity of pycnogonid (sea spider) species; and has very diverse and dense bryocoan communities (Baker & Edyvane 1996, S Shepherd SARDI pers comm. Within Encounter Bay, the almost continuous and extensive dense seagrass areas are the only signficant areas of dense seagrass on the southern Fleurieu Peninsula coast. This may explain the regional importance of this region for Sygnathids (Edyvane 1998). Likewise the extensive granite reef system, which is a feature of Encoutner Bay between Rosetta Head and the mouth of the Inman River, is the only significant reef system on the southern Fleurieu Peninsula coast (Edyvane 1998). For these and other (cultural, social, geological) reasons, Encounter Bay has been nominated as a potential Marine Protected Area several times during the past two decades (Halstead 1987, Edyvane 1998). A full list of marine conservation attributes of the Encounter Bay region is detailed in Baker & Edyvane (1996) and more recently, in Edyvane (1998). Page 192 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT − − − − − As well as displaying considerable biodiversity, the Encounter Bay region also exhibits a high level of geodiversity. This is due to the presence of the Encounter Bay Granite Province, the variation within the granite itself, and the inclusions, and also, the metamorphic eureole surrounding the bathloith. Many features are best exposed in the intertidal zone, for eg around the flanks of Rosetta Head. The waters around Granite and West Islands are also the only known location for a number of species of hemichordates (S. Shepherd, SARDI, pers. comm.). Marine life surrounding West Island is presently protected within the West Island Aquatic Reserve, which comprises approximately 84 ha. The reserve was established primarily for the protection of the marine benthic organisms around the island for long term ecological studies. The island itself is located 800 metres offshore at the north western end of Encounter Bay. As such, it's accessibility has made it a popular research site for many marine biological studies. Major habitat types include, submarine cliffs, crevices and caverns, sandy and rocky seabed areas. The general features of the algal vegetation change markedly around the island passing from rough to more sheltered coasts. Three habitat types have been recognised: the rough water southern and western coasts; the moderately rough water sections on the eastern and northern shores; and the semisheltered section of Abalone Cove. To the lee of the island, extensive beds of seagrasses are present. West Island and Granite Island also support rich birdlife including large and important sites for breeding colonies of sea birds including, Little Penguins (Eudyptula minor), Silver Gulls, Crested Terns, Caspian Terns and Fairy Terns. Rosetta Head also has a population of Little Penguins. Birdlife is presently protected within the West Island Conservation Park, which includes Seal Island. The park is also on the Register of the National Estate. Granite Island has a Recreation Park, and is, likewise, on the Register of the National Estate. Leafy and Weedy Sea Dragons are highly ornate species of sea horse which are camouflaged to resemble the seaweeds and seagrasses in which they hide. They are considered to be highly unusual and beautiful creatures and are currently fully protected. Sea dragons are generally associated with the algal communities at West Island and Rosetta Head (ie. the Bluff) and also, around the rocky areas of Encounter Bay. − The deep waters of Backstairs Passage contain massive sponges of more than 1 metre high and wide. Large erect bryozoans (e.g. Adeona grisea) dominate the bottom, and epizoic crinoids and ophiuroids are especially abundant on them. In the sediment drifts the brachiopod Magadena cuingi reaches densities of up to 80/m2 (Richardson & Watson 1975, in Shepherd & Sprigg 1976). − Although there are no major colonies of seals in this region, sightings are made of the Australian Sea Lion (Neophoca cinerea) and Australian Fur Seal (Arctocephallus pusillis), and it is possible that they are returning to this area. For instance, Australian Fur Seals appear to be returning to Seal Rock. − Deep Creek Conservation Park is on the Register of the National Estate. Within the park, Blowhole Creek is a popular diving location and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). − Newland Head Conservation Park is on the Register of the National Estate. 1.2 − Physical The high cliff coastline of this biounit is generally considered to be quite spectacular and has, therefore, aesthetic qualities. Geological Monuments − Middleton Beach: part of the Kanmantoo Group and type section of Middleton Sandstone with sedimentary structures. − Encounter Bay region (Port Elliot including Commodore Point, Pullen Island, The Sisters Rocks and Freeman Knob): Encounter Bay Granite outcrops. This area is on the Register of the National Estate. − Victor Harbour, banks of the railway cutting: Late Pleistocene Anadara shell beds. − Victor Harbour, Granite Island and Seal Island: Encounter Bay Granite and Kanmantoo Group. On the Register of the National Estate. Page 193 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT − Rosetta Head/The Bluff, Petrel Cove and Wright Island: Encounter Bay Granite contact with Kanmantoo Group rocks including Petrel Cove Formation Type Section. Rosetta Head and Wright Island are on the Register of the National Estate. − West Island, King Beach and King Point: Encounter Bay Granite and Kanmantoo Group Rocks. The Balquihidder Formation extends West to Newland Head, which is on the Register of the National Estate. − Headland between Waitpinga Beach and Parsons Beach: part of Kanmantoo Group Type section and Balquhidder Formation. This headland lies within an Aboriginal site on the Register of the National Estate. The Kanmantoo Group type section continues West from the end of Parsons Beach to Tunk Head and beyond. − Tunkalilla Beach including old cliff line: part of Kanmantoo Group type section. − Deep Creek: part of Kanmantoo Group type section. − Cape Jervis: type section for Cape Jervis Beds and Permian Glaciation. This area is on both, the State Heritage List and the Register of National Estate. 2 2.1 OTHER VALUES Commercial Fisheries Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours, respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster Backstairs Passage (and also, north western Kangaroo Island) (ie. Fishing Zone 44). In 1995/96 and 1996/97 a total of 8 and 6 licensed operators fished in this region (ie. Fishing Zone 44), catching approximately 7,036 and 5,390 kg of lobsters, respectively (or 0.14% and 0.11% of the total catch for Southern Rock Lobster in South Australian waters). Abalone There is negligible commercial harvesting of Greenlip Abalone in this biounit, (ie. MapCode 25A-D, Yankalilla Bay to Port Elliot, including Backstairs Passage and the Pages). In 1995/96 a total of 3498 kg of Blacklip was harvested within this region, which represented 8.3% of the total Blacklip Central Zone catch (or 0.76% of the total catch for Blacklip in South Australian waters). No Blacklip were harvested in this region in 1994/95. Marine Scalefish Fisheries The Encounter Biounit encompasses 2 fishing zones: Fishing Zone 44 and 45. During 1995/96 and 1996/97, 21 and 17 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the Encounter Bay section of this biounit (ie. Fishing Zone 45), respectively. License holders expended approximately 651 and 437 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 45) represented 52,019 kg in 1995/96 and 35,468 kg in 1996/97(or 0.50% and 0.35% of the total catch for the marine scalefish fishery in South Australian waters). In the southern Fleurieu and Backstairs Passage region, west of Newland Head (ie. Fishing Zone 44), a total of 47 and 37 licensed operators fished 2496 and 2,126 days in this region in 1995/96 and 1996/97, catching approximately 171,288 and 129,167 kg, respectively (or 1.65% and 1.27% of the total catch for the marine scalefish fishery in South Australian waters). At Cape Jervis there are 10-15 full-time line fishers (hand and long line). Main species targetted are Southern Calamari (Sepioteuthis australis) which are caught over seagrass beds, and Snapper (Pagrus auratus) which are caught between 50 m and 10 m. Beach seining for Salmon and Mullet occurs on the sandy beaches adjacent Cape Jervis. This biounit encompasses 2 fishing zones: Fishing Zone 44 and Fishing Zone 45. In 1995/96 and 1996/97 a total of 3 and 2 licensed operators fished in the waters of Encounter Bay (ie. Fishing Zone 45). In addition, lobster fishing is also present in the waters of the southern Fleurieu Peninsula and Page 194 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT Some line fishing occurs at Deep Creek for King George Whiting (Sillaginodes punctata) and Snapper. There is also a small amount of netting for Australian Salmon (Arripis trutta esper) and mullet (eg. Aldrichetta forsteri), particularly around Encounter Bay and Victor Harbour. − Central Gulf Management Zone (waters offshore from Port Gawler) – zoned to provide for aquaculture development. Licenses will be considered for a total of 100ha of aquaculture development in this zone, excluding the culture of Pacific Oysters. Backstairs Passage has an active hand/long line Snapper fishery, while Southern Calamari is taken by jig nearer to Cape Jervis. Some Garfish is also caught here. − Investigator Strait/Backstairs Passage Zone (waters of Investigator Strait and Backstairs Passage) – zoned for aquaculture development. Licenses will be considered for a total of 50ha of aquaculture development in this zone. Licenses will not considered for developments east of line between Cape Jervis and Penneshaw. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Victor Harbour: 5 northern zone Rock Lobster licenses, 1 southern zone Rock Lobster, 1 restricted marine scalefish license, 7 unrestricted marine scalefish licenses. − Port Elliot: 1 restricted marine scalefish licence. − Goolwa: 1 unrestricted marine scalefish license. 2.2 Fleurieu Policy Area − West Fleurieu Management Zone (coastal waters, within 3nm of the coast, from Sellicks Beach to Cape Jervis, excluding Rapid Bay) – zoned for limited aquaculture development. Licenses will be considered for a total of 30ha of aquaculture development in this zone, excluding the culture of Pacific Oysters. − − Cape Jervis: boat, jetty and rock fishing. Major species: King George Whiting, Australian Salmon, Snapper, Snook, Garfish, Bluefin Tuna, Tommy Rough, Toothbrush Leatherjacket and Southern Calamari. There is one charter boat operator based at Cape Jervis. − Waitpinga and Parsons Beach: beach and rock fishing. Major species: Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon and Mulloway. − Port Elliot and Middleton: beach, jetty and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Mulloway, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket and Southern Calamari. − Victor Harbour, The Bluff (Rosetta Head) and Granite Island: beach, boat, jetty and rock fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Sweep, Garfish, Tommy Rough, Toothbrush Leatherjacket and Southern Calamari. East Fleurieu Zone (coastal waters, within 3nm of the coast, from Cape Jervis to the Murray Mouth) – zoned to protect tourism, recreation and conservation values. Licenses will not be considered for aquaculture development in this zone. Open Waters Policy Area Central Gulf Zone (offshore waters of central Gulf St Vincent) – zoned to maintain commercial and recreational use. Licenses will not be considered for aquaculture development in this zone. Recreation and Tourism Fishing Aquaculture There is currently no aquaculture in this region. The Gulf St Vincent/Fleurieu Aquaculture Management Plan (Berggy 1996) proposes no aquaculture development in this region: − 2.3 Tourism − Deep Creek Conservation Park is a popular place for bushwalking and fishing at the mouth of Blowhole Creek. Page 195 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT − The entire Encounter Bay area is a major tourist destination in South Australia. Victor Harbour, Port Elliot and Goolwa are all popular tourist and recreation sites, chiefly due to their proximity to Adelaide and coastal outlook. Popular activities include swimming, surfing, boating, sailing, SCUBA diving, visiting Granite Island to see the penguins, whale watching during winter, visiting historical sites and general sightseeing. It is a particularly popular place for retirees and families. The long expanses of beach are ideal surfing and swimming areas, whilst the tall cliffs at Tunk Head allow for spectacular hang gliding. There is one charter boat operator in Victor Harbour. − The Bluff is also known as Rosetta Head. This 100 m granite outcrop has good walking trails and magnificent views of Encounter Bay, Victor Harbour and the surrounding countryside. The Bluff is one of the most popular dive sites in South Australia. The granite headland provides good reefal habitat for a wide range of marine life, including, lobsters, cuttlefish, seals and a wide range of fish, including Weedy and Leafy Sea Dragons. − 2.4 − − − West Island itself is a Conservation Park surrounded by an aquatic reserve (ie. West Island Aquatic Reserve). The aquatic reserve was established in 1966 specifically for scientific research purposes, in order to protect and study the resident Abalone population (Haliotis sp). As such, research studies on this species have continued for over 20 years and have provided valuable information on the population dynamics of this species. In addition to research on Abalone, scientific studies have also examined the major benthic communities around the island, in an attempt to understand fundamental marine ecological processes. A small field station is located on the island, and this is used by a number of postgraduate students, researchers, and interstate and overseas visiting researchers. No fishing is permitted within this area. − Rosetta Head (including Kings Beach and Rosetta Bay) have been used regularly by both, the University of Adelaide and Flinders University, for the past 30-15 years as an area for teaching marine biology. At Kings Beach, the rocky shore and intertidal pools support a diverse range of crustaceans, molluscs, starfish, sea cucumbers, sea anemones and other benthic organisms. This whole area has suffered a substantial decline in the populations of some of the species, especially starfish and sea cucumbers (Dr. J. Orbach, pers. comm.). As this area is not currently protected, it is possible that people are removing the organisms as souvenirs or food items. SCUBA diving: Rapid Head, the Bluff (Victor Harbour), West Island (Victor Harbour), and Blowhole Creek (Deep Creek Conservation Park) are all popular diving locations in this region and are all listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia. Scientific Research and Education The Botany Department of The University of Adelaide has ongoing research into the ecology of marine plant communities near the Cape Jervis jetty. The whole of the West Island, Seal Island, Granite Island, and Rosetta Head region is one of the most significant areas for marine biological research in South Australia. This is primarily because of the rich diversity of marine habitats and its proximity to metropolitan Adelaide. As such, many marine research studies have been, and will continue to be, undertaken in this important locality. 2.5 Adjacent Land Use National and Conservation Parks − Deep Creek Conservation Park (4,228 ha). − Newland Head Conservation Park (1,036 ha). − West Island Conservation Park (18 ha), includes Seal Island and the West Island Aquatic Reserve (65 ha) (SANPWS 1983). − Granite Island Recreation Park. − Pullen Island Conservation Park (SANPWS 1983). Page 196 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT whaling company arrived. The industry flourished until the 1860's. In 1839, the first settlers arrived under the leadership of Reverend Ridgeway Newland. Victor Harbour and Port Elliot soon became important ports. However, after many shipwrecks and the extension of the railway to Victor Harbour, Port Elliot's days as a shipping port ceased. Victor Harbour declined as a predominant port when river trade was diverted directly to Adelaide, and the towns became tourist resorts. Agriculture/Industry − Areas not set aside for conservation parks in this biounit have generally been cleared of native vegetation and used for agriculture and grazing, or for urban development. − Major sources of marine pollution in this biounit include: outlets at Hindmarsh River, Inman River (also a sewage outlet) and Watson Gap. Urban Centres − Victor Harbour (population , 318). − Goolwa (population 2,360). 2.6 Features − There are historic sites along the foreshore between Rosetta Head and south Goolwa associated with early settlement of the area. − Cape Jervis is also a significant site for European history as it was named by Matthew Flinders is 1802 and a whaling industry established during the 1840's, continuing until 1855. The town is also the site of a lighthouse established in 1871. Significant Cultural and Historical Aboriginal Shipwrecks − − The Aboriginal group occupying the Encounter Bay area at the time of European settlement of South Australia were the Ramindjeri people. According to Aboriginal legend, Granite Island and West Island feature in the legend of the great totemic being Ngurunderi. He was responsible for making these islands and other features during his Dreamtime journey down the Murray Valley in pursuit of his two unfaithful wives. Aboriginal sites at Waitpinga cover approximatley 20 ha, and are on the Register of the National Estate (Bilney et al, 1981, cited by Baker and Edyvane, 1996). The sites comprise campsites, Kartan tools, hearths and shell middens. at other Aboriginal sites at Cape Jervis, large pebble and block Kartan tools are indication sof some of the earliest Aboriginal occupation on the Fleurieu Peninsula (Ross, 1984, cited by Baker and Edyvane, 1996). On King’s Beach exists a natural sandtrap, which was made and used by the Ramindjeri living in Encounter bay (Shepherd, pers. comm. cited by Baker and Edyvane, 1996). − Encounter Bay was the site of the earliest shipwreck the `South Australian' in 1837. − The historic shipwreck `Victoria’ lies off Tunkalilla Beach. − `Solway' in 1837 was built in Britain and was wrecked near Victor Harbour whilst transporting German immigrants to Adelaide. The wreck is located on a sandy patch 150 metres inshore from the face of Blacks Reef in 3-4 metres of water. − `Harry', built at Dorset, United Kingdom in 1842 and wrecked near Port Elliot in 1856. The remains of this vessel are located in 3-4 metres of water near Commodore Point and are an excellent example of wooden ship construction from the 1840's. − A total of seven other ships were wrecked in Horseshoe Bay, Port Elliot between 1853 and 1864. European − The Encounter Bay area is an important area for European History in South Australia. It was so named by Captain Matthew Flinders after he met the French navigator Baudin here in 1802. The first settlement at Encounter Bay occurred in 1837 when the Robert Campbell Page 197 GULF OF ST VINCENT – FLEURIEU PENINSULA REGION – ENCOUNTER BIOUNIT 3 CURRENT CONSERVATION STATUS OF THE ENCOUNTER BIOUNIT − Marine Reserves West Island Aquatic Reserve (65 ha) − Marine Parks None − Encounter Bay 42 − Netting Closures Parson's Beach (north of a line from the eastern end of the beach to the western end). − Waitpinga Beach (north of a line from Newland Head to the western end of the Waitpinga Beach) − Hindmarsh and Inman Rivers (the waters of Hindmarsh and Inman Rivers and within 200 m of their mouths). 4 AREAS OF HIGH CONSERVATION VALUE IN THE ENCOUNTER BIOUNIT Deep Creek - Newland Head − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (`geological monuments'-Deep Creek, Tunkalilla Beach), ecological (range of coastal marine habitats, reefs, estuaries-Tent Rock Creek, `endangered' Leafy Sea Dragon, reef fish populations), economic (marine scalefish fisheries-King George Whiting, Shark, Calamari, Snapper, Salmon, Mullet), social (aboriginal significance-Waitpinga Beach, recreation, historic shipwrecks- `Victoria’), scientific (marine biological research/monitoring at Cape Jervis region), national (Register of the National Estate-Deep Creek, Newland Head Conservation Parks, Waitpinga Beach), practicality (insulation, accessibility, compatibility-Deep Creek, Newland Head Conservation Park). Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, cultural, social values (IUCN Category II). IUCN Identification Criteria: biogeographic (representativeness, wide range of geological features, `geological monuments'-entire Encounter Bay region, Middleton Beach, Encounter Bay), ecological (range of coastal marine habitats, reefs, seagrass meadows, estuaries-Inman River, Hindmarsh River, islands, `endangered species'-Leafy Sea Dragon, Southern Right Whale, `rare' Australian Sea Lion, seabird breeding coloniesLittle Penguins, Crested Terns, Caspian Terns, Little Terns, Silver Gulls, White-breasted Sea Eagles, Little Falcons, numerous coastal wading birds), economic (marine scalefishShark, Calamari, Snapper, Snook, Australian Salmon, Abalone, tourism-diving, fishing, boating), social (recreation, education-Whale Watch Centre, penguin watching, Rosetta Head, historic shipwrecks-`Solway', `Harry', `South Australian', aboriginal fish traps-Kings Beach, aboriginal sites-Middleton, Sir Richard Peninsula), scientific (marine biological research/teaching-Rosetta Head, West Island, Granite Island), national (Register of the National Estate-Rosetta Head, Wright Island, Granite Island, Seal Island), practicality (accessibility, compatibility –adjacent to West Island Aquatic Reserve/Conservation Park). Pages Conservation Park − Prime IUCN Conservation Values: rare and endangered species/habitats, research, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative marine habitats, global importance for Australian Sea Lions), ecological (largest breeding colony of `rare' Australian Sea Lion in the world, spawning area-Snapper, Western King Prawn, high marine biodiversity-sponge gardens, brachiopod diversity), economic (marine scalefish-Shark, Calamari, Snapper, Snook, Australian Salmon, Southern Rock Lobster), scientific (research/monitoring-Australian Sea Lions), national (potential for listing on the Register of the National Estate), practicality (insulation, accessibility, compatibilityadjacent to Pages Conservation Park). 42 The Encounter Bay region was formally nominated for conservation management as an Aquatic Reserve by Halstead (1987). Page 198 KANGAROO ISLAND COAST MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE KANGAROO ISLAND COAST MARINE BIOGEOGRAPHY 1. 2. 3. 4. 5. Kangaroo Island Oceanography Climate Geology and Coastal Geomorphology Biology MARINE CONSERVATION VALUES 1. 2. 3. Significant biological and Physical Features Significant Cultural and Historical Features Current Conservation Status of the Kangaroo Island Coast BIOUNITS 1. Nepean and Backstairs 2. Gantheaume 3. Cassini Page 199 KANGAROO ISLAND COAST MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE KANGAROO ISLAND COAST MARINE BIOGEOGRAPHY 1 KANGAROO ISLAND Kangaroo Island, off the southern coast of Fleurieu Peninsula, South Australia, is Australia's third largest Australian isle (following Melville Island and Tasmania). The island encompasses some of South Australia's most popular tourist destinations (such as Seal Bay and American River) and is well-known for its spectacular coastline and coastal wilderness areas (such as the Flinders Chase National Park). The island currently contains all 5 of South Australia’s wilderness areas declared under the Wilderness Protection Act 1992. Kangaroo Island (along with the Pages Islands in Backstairs Passage), is also a region of considerable conservation significance for marine fauna and flora, particular mammals, and includes not only major breeding areas for the rare Australian Sea Lion and the New Zealand Fur Seal, but also areas which are regularly frequented by the endangered Southern Right Whale on their northward migration to the calving and breeding areas at the Head of the Great Australia Bight (Inns et al. 1979). Historically, the rugged southern and western coast of Kangaroo Island also comprises some of the major sites of maritime significance in South Australia. The latter, containing an unusual concentration and density of shipwrecks of high cultural value. Kangaroo Island is also characterised by a wide range of coastal landforms from the sheltered tidaldominated coastal lagoons on the northeast coast (eg. Pelican lagoon, American River inlet), to spectacular wave-exposed coastal cliffs along the south coast (such as Cape de Couedic). The island itself has a strong influence on the oceanography, and thus geomorphology, of the South Australian coastline, particularly the Gulf St Vincent Bioregion. Situated at the head of Gulf St Vincent, the large island essentially shelters the adjacent mainland coastal regions from the high wave energies of the Southern Ocean. 1.1 Biogeography of Kangaroo Island Along the southern coast of Australia, marine biogeographers recognise a major biogeographic region, known as the Flindersian Province, which extends from southwest Western Australia to southern New South Wales and includes the waters of Victoria and Tasmania. Within this broad region, the coastal waters of the Great Australian Bight (west of Robe) are recognised as warm to cool temperate (in contrast to the cold temperate waters of the southeast of Australia, east of Robe). Within the Flindersian Province, the Kangaroo Island coastal and marine ecosystems encompass 2 welldefined biogeographical regions known as the Gulf St Vincent Bioregion and the Eyre Bioregion. The north coasts of Kangaroo Island encompass the Gulf St Vincent Bioregion, which extends from West Cape to Cape Borda (Kangaroo Island), and from Cape Jervis to Cape Willoughby (IMCRA 1997). However, the southern and western coast of Kangaroo Island, from Cape Borda to Cape Willoughby, falls within another marine biogeographic known as the Eyre Bioregion, which extends from Cape Bauer to Cape Borda, to West Cape, to Port Neill and Cape Willoughby (IMCRA 1997). A complete physical and ecological biogeographic description of the Gulf St Vincent Bioregion and also, the Coorong Bioregion, including marine fauna and flora, has been described by IMCRA (1997). Based on coastal geology, wave climate, and coastal orientation, Short and Fotheringham (1986), identified three coastal geomorphological regions (or subprovinces) for the Kangaroo Island coast: 1. 2. 3. Northern Coast Subprovince (from Cape Borda to North Cape, 111 km) North-Eastern Coast Subprovince (from North Cape to Cape Willoughby, 114 km) Southern and Western Coast Subprovince (from Cape Willoughby to Cape Borda, 232 km) Page 200 KANGAROO ISLAND COAST These coastal subprovinces correspond to 3 finerscale marine biogeographical regions or biounits: 1 2 3 2 2.1 Cassini Biounit (from Cape Borda to North Cape, 111 km) Gantheaume Biounit (from North Cape to Cape Willoughby, 114 km) Nepean Biounit (from Cape Willoughby to Cape Borda, 232 km) OCEANOGRAPHY Wave Climate The western and southern coasts of Kangaroo Island have a distinct cool-temperate climate. Most of this coastal region is fully exposed, almost year round, to strong prevailing winds (from the south and west) and the Southern Ocean, which result in moderate to high energy, south west to westerly swells and surge conditions. Areas along the more exposed regions of this coast (eg. Cape du Couedic, Cape Borda and Cape Willoughby), show a persistent year round southwest to westerly swell of 2-4 m for approximately 50% of the year. This swell is most persistent from March to October, but decreases slightly in occurrence between November and February. Lower wave energy areas occur only in the east-facing D’Estrees Bay. In contrast, the north coast of Kangaroo Island has a predominantly low wave energy regime. This is due principally to its sheltered northern aspect. The calmest part of the north coast of Kangaroo Island is the almost landlocked area of American River inlet. Here wave action is almost negligible on the tidal flats except when strong winds blow across the lagoons. The tides in this province are typical for South Australian waters, ie. they are a `mixed' type, comprising both a semi-diurnal (ie. two high tides and two low tides daily), and a diurnal (one high tide and one low tide daily) phase. `Dodge tides' or periods of minimal semi-diurnal tidal movement, occur during neap periods on the northern side of Kangaroo Island and around the American River inlet region. During this time, only one tide per 24 hr occurs over 2-4 days in the neap period, but two tides of less amplitude may occur. When the single tide occurs, the low level is usually lower than tides before and after, while the high may be nearly as high as some spring tides. The neap period varies from a day before the first and third quarters of the moon to 4 or 5 days after. Tides are of relatively small amplitude and show some variation from place to place. On the exposed coasts of this province, the spring range is approximately 0.8-1.3 m, increasing to 1.3-1.7 m on the north coast of Kangaroo Island. The height of the tide may be greatly modified by winds. On exposed coasts, a strong offshore wind generally keeps the sea-level down. Mean sea-level, and other tidal means, are highest during winter and lowest during summer months, the difference being as much as 15-20 cm. January-February is the period of the lowest sea-level and thus the lowest tides. In general, the lower of the two daily low tides occurs during the middle of the day in summer (October-April) and in the middle of the night in winter (June-September). The higher of the two daily low tides occurs in the early hours of the morning during summer, and in the afternoon during the winter. The lower of the high tides is the opposite of this. 2.2 Water Temperature and Salinity Offshore sea surface temperatures along the Kangaroo Island coast are typical for the western and central coasts of southern Australia, ranging from mean sea surface temperatures of approximately 1820oC in summer to 14-16oC in winter. Inshore temperature variations, particularly in sheltered bays and inlets, are generally much greater. Temperature anomalies may also arise from the deep water submarine canyons located 60 km south of the Kangaroo Island. On the shallow, sheltered, northeastern coast of Kangaroo Island, the depth of water and degree of wave action causes a greater temperature range. For instance, on the tidal flats of American River inlet, water temperatures range from 320C to 100C. In the Vivonne Bay area, isolated rock pool temperatures of 30 to 400C are frequent in summer. The salinity of the waters in Backstairs Passage and around Kangaroo Island and Encounter Bay is relatively uniform (35.5%. to 36%.). However, slight salinity increases do occur in the sheltered lagoons of Kangaroo Island during summer. 2.3 Currents and Upwellings A surface current flows from west to east along both sides of Kangaroo Island and is strongest in the period from May to July. The currents in Backstairs Passage are largely tidal and dominate the northern part of the coastline. Page 201 KANGAROO ISLAND COAST The inshore regions of the northwest coast of Kangaroo Island are under the influence of seasonal coldwater, nutrient-rich coastal upwellings which occur close to the coast, and can result in an offshore sea surface temperature gradient of 18oC to inshore temperatures of 11oC in inshore areas during the summer months. The major focus of the coastal upwelling extends from Point Sir Isaac (Coffin Bay Peninsula) to Cape Borda (Kangaroo Island) (Wenju et al. 1990), and is responsible for the very high levels of productivity and pilchard abundance in the region (Ward & McLeay 1998), and may be linked to the abundance of seabirds, marine mammals, and high levels of marine benthic biodiversity in the region. Geologically, Kangaroo Island is an extension of the most southerly part of the Mt Lofty Ranges known as Fleurieu Peninsula, but separated from it by the waters of Backstairs Passage (Daily et al. 1979). As such, the southern Fleurieu Peninsula, from Cape Jervis to the mouth of Murray River, is geomorphologically very similar to the Kangaroo Island coast and hence, is considered a part of the Kangaroo Island Province. The coastal geomorphology of Kangaroo Island has been extensively studied (see Short & Fotheringham 1986) and is detailed below under the relevant biounits. 3 5.1 CLIMATE 5 BIOLOGY General Ecology The climate of Kangaroo Island and southern Fleurieu Peninsula is typically `cool temperate', with a distinct winter rainfall maximum, but with relatively mild conditions during summer and winter. The main influences on the climate of this region are the prevailing mid-latitude anticyclones or high pressure systems, and the moderating effect of the surrounding ocean. The biology of Kangaroo Island, and particularly it’s marine component, has long been recognised by marine biologists as one of the richest and most fascinating biotas of the southern Australian coasts: 4 This richness is partly due to the great variety of coastal habitats provided by the island (Womersley & Edmonds 1979). These marine habitats include: exposed rocky shores, estuaries and tidal flats, sandy beaches, protected bays, open ocean surf zones, reefs, islands and offshore submarine canyons. GEOLOGY AND GEOMORPHOLOGY 43 COASTAL Kangaroo Island is primarily composed of folded Precambrian and Cambrian metasediments of the Adelaide Geosyncline series. These metasediments are exposed at many locations along the coast. Igneous rocks of Cambrian, Permo-Carboniferous rocks of glacial origin, marine Tertiary and marine Quaternary are also exposed along the coast. Beach and aeolian sediments of Pleistocene and Holocene Epochs occur along the coast and particularly along the south and west coasts. The overall outline and much of the detailed shoreline configuration of Kangaroo Island is controlled by the pre-Quaternary bedrock geology and denudation. Under various sea levels the bedrock has been attacked to form sea cliffs and large amounts of carbonate shell detritus from the inner shelf has been moved through beaches to form massive dune systems along the south and west coasts. These systems have in turn been lithified during low sea levels which are then eroded during higher sea levels to form calcarenite sea cliffs. Elsewhere the seas have reworked terrigenous material along the north and northeast coasts where they form generally low energy beach and tidal flat deposits. The pre-Quaternary bedrock geology and Tertiary denudation dominates the gross morphology of the entire Island. 43 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). "...a thorough analysis may well show that the diversity of marine life is as great or even greater than on the Great Barrier Reef.” (Womersley & Edmonds 1979). The intertidal coast of Kangaroo Island is similar to the central and western coasts of South Australia (Womersley & Edmonds 1958). In the supralittoral Littorina unifasciata is dominant (except where conditions are very calm) and at high levels on very exposed coasts Calothrix fasciculata is found. The littoral zone, where the coast is most exposed, consists of barnacles - Chthamalus antennatus and Chamaesipho columna in the upper littoral, Catophragmus polymerus in the mid littoral, and Balanus nigrescens in the lower littoral - but where the coast is more sheltered it consists of molluscs in the upper and mid littoral and algae (Corallina cuvieri, Gelidium pusillum, or Hormosira banksii) in the lower littoral. In the upper sublittoral fucoid algae or in calm regions, marine angiosperms, are dominant. Womersley & Edmonds (1979), in their account of the intertidal ecology of Kangaroo Island, described 3 distinct regions: (i) coasts subject to strong wave action (ie. south and west coasts, extending along the north coast to approximately Western River; (ii) coasts subject to moderate wave exposure (ie. most of the north coast); and (iii) protected coasts with no or little wave action and sandy-mud tidal flats (ie. American River inlet). Page 202 KANGAROO ISLAND COAST The marine benthic flora of Kangaroo Island is extremely rich and diverse and includes over half of the species found in southern Australia (Womersley & Edmonds 1979). Rocky coasts are dominated by algae and in sheltered coastal waters and estuaries, seagrasses are dominant. Five genera of seagrasses, plus two normally brackish water angiosperms (Ruppia and Lepilaena) and approximately 500-600 species of marine algae have been recorded from the coastal waters. These include the brown algae Cystophora intermedia which occupies the sublittoral fringe where strong wave action occurs. In more sheltered areas it is replaced by other species of Cystophora or Ecklonia radiata. Sand and sandy mud formations (eg. American River tidal inlet), are dominated by extensive seagrass meadows, dominated by species of Posidonia and Zostera. 5.2 Subtidal Ecology 44 5.2.1 Strong Wave Action Coasts The southern and western coasts of Kangaroo Island are characterised by strong wave action, steeply sloping coasts of Palaeozoic rock (ie. granite, gneisses) which form most of the headlands, interspersed with horizontal calcareous platforms, and sandy beaches. In zonation, the steeply sloping Palaeozoic rocky coasts of southern and western coast of the island are similar to Point Sinclair, Cape Carnot (western Eyre Peninsula) (Womersley & Edmonds 1958). The sublittoral fringe on the rocky coasts are typically dominated by Cystophora intermedia, while the sublittoral is dominated by species of Cystophora, and Sargassum and red algae. On calcareous reefs in particular, the kelp Ecklonia radiata, numerous species of fucalean algae (ie. Cystophora, Sargassum, Myriodesma, and Scytothalia), and a great variety of red algae occur (Womersley & Edmonds 1979). Within the sublittoral, the following zones have been recognised: upper sublittoral zone: dominated by a turf of Corallina cuvieri, with Cystophora intermedia and Balanus barnacles, Gelidium glandulaefolium and Curdiea gymnogongroides, Melanthalia spp., Sargassum spp. and Zonaria sinclairii; the mid sublittoral zone: dominated by Ecklonia radiata and other brown algae (Scytothalia dorycarpa, Acrocarpia paniculata, Cystophora spp. and Myriodesma spp.), and Melanthalia; and the lower eulittoral zone: lies below the zone of larger brown algae and consists of a dense cover of diverse red algae, including especially species of Plocamium (Womersley 1990). The fauna becomes more prominent as the limits of the photic zone are approached. 44 From Edyvane KS & JL Baker (1996). Marine Biogeography of Kangaroo Island. 5.2.2 Moderate Wave Action Coasts The northern coast of Kangaroo Island is characterised by rocky sheltered coasts of moderate wave action, interspersed with sandy beaches. In zonation, the moderately sheltered coasts of the north coast are similar to the southern parts of Gulf St Vincent (Womersely & Edmonds 1958). On rocky coasts subject to some wave action, the upper sublittoral zone is typically dominated by larger brown algae, especially Ecklonia radiata, Cystophora subfarcinata, C.retorta, C.polycystidea, C.moniliformis and other species, Caulocystis cephalornithos, Cystophyllum onustum and Sargassum spp. (such as S.decipiens, S.lacerifolium), with an understorey of coralline algae (for eg. Amphiroa anceps, Cheilosporum elegans), Cladostephus spongiosus and often species of Caulerpa (Womersley 1990). On sandy bottom below rocky areas the seagrasses Amphibolis and Posidonia often cover very extensive areas as dense, often pure, communities. Aeolianite dunes along the north coast of Kangaroo Island form prominent sea floor eminences and a rough bottom topography. This provides an excellent substrate for a rich variety of benthic organisms such as algae, sponges, crinoids and reef molluscs. A varied fish population including excellent Southern Rock Lobster and Snapper grounds are also found in these habitats (Shepherd & Sprigg 1976). 5.2.3 Coasts of Slight Wave Action The coast of north-eastern Kangaroo Island comprises coasts of slight wave action, with sandy or muddy flats or beaches, comprising almost landlocked bays, such as American River inlet. The intertidal and subtidal ecology of American River inlet has been well described by Womersely (1956). The lower eulilttoral zone of American River inlet is dominated by Hormosira banksii (Sea Grapes or Neptunes Necklace) which is usually growing on the large mussel Austromytilus erosuss. Mats of Chaetomorpha and other small algae may occur here. Fauna includes the starfishes Patiriella exigua and Uniophora. In the upper sublittoral zone there is a marked change to a seagrass dominated habitat. Species of green and red algae are common in the uppermost sublittoral zone. Heterozostera is found just above low tide level to 2 m deep and Posidonia covers extensive areas of the flats below low tide level. Halophilia is found along the edge of the channel or in deeper areas. Large plants of the brown algae Sargassum biforme and Scaberia occur in the channel, usually attached to submerged boulders or rocks. Epiphytic algae is found on Posidonia (Womersley 1956). Fauna include sponges, starfishes, anemones, holothurian, polychaetes and Page 203 KANGAROO ISLAND COAST the razor fish Pinna. Fish species include sting rays, eagle ray and small sharks (Womersley & Edmonds 1979). American River is also a known nursery area for King George Whiting (Sillaginodes punctatus) and an extensive feeding area for aquatic birds. On the sheltered coasts in this region, seagrass beds are generally well developed on sandy-muddy areas of tidal flats, extending several metres deep. Heterozostera tasmanica forms dense and pure masses in thick, firm mud from low tide level down for 3-4 m, with occasional plants as deep as 20m (Womersley 1990). Posidonia (tapeweed) extends large distances from about 0.5m below low tide to 20m or so deep. P.australis is the most widespread species of tapeweed and it grows sympatrically with P.sinuosa and P.angustifolia in the shallower part of their range. P.sinuosa is widely distributed to a depth of 15m in sheltered bays and inlets, either in pure stands or growing sympatrically with P.australis or P.angustifolia. In more exposed areas it may form meadows with Amphibolis spp.. P.angustifolia grows subtidally from 2-35 m deep. It frequently grows in deeper water than P.australis. In its deeper range it is often found in association with Heterozostera tasmanica or Halophila australis and in sheltered positions in its shallower range in association with Amphibolis antarctica. The Posidonia leaves often carry a wealth of epiphytes but only few macroalgae (for eg. Caulerpa cactoides, C.remotifolia) occur in or adjacent to the beds. Common algae at and just below low tide level are Hypnea musciformis, Spyridia filamentosa, Ulva lactuca, Enteromorpha clathrata, Centroceras clavulatum, Cladophora spp., and often Polyphysa peniculus epiphytic on old cockle shells. Molluscs, echinoderms, crustaceans and small fish are usually common in this zone. 5.3 Fish The fish fauna of the Kangaroo Island Province is diverse but typical of the species found along the southern coast of Australia. As such, the fish fauna of this province falls within the biogeographical province known as the Flindersian Province. Along the inshore coastal waters and inland waters of Kangaroo Island, some 231 known species of fish have been recorded. Seahorses, Seadragons), Gobiidae (Gobies), Ophiclinidae (Snake Blennies), Clinidae (Weedfishes), Labridae (Parrot Fishes), Neoodacidae (Weedy Whiting, Rock Whiting, Herring Cale), Gobiesocidae (Clingfishes, Shore Eels) and Monacanthidae (Leatherjackets). 5.4 Reptiles A number of itinerant species of marine turtles have been recorded along the Kangaroo Island coast. These include, the Loggerhead Turtle (Caretta caretta), Green Turtle (Chelonia mydas) and the Leathery Turtle (Dermochelys coriacea) (Houston & Tyler 1979). 5.5 Seabirds Some 216 species of birds have been reported from Kangaroo Island (Ford 1979). Seabirds include Little Penguins (Eudyptula minor), four species of cormorants, Black-faced Shags (Leucocarbo fuscescens), and Silver and Pacific Gulls (Larus novaehollandiae, L.pacificus). Caspian, Crested and Fairy Terns (Hydroprogne caspia, Sterna bergii, S.nereis) are present throughout the year and all probably breed on the island. In winter, albatrosses such as the Yellow-nosed (Diomedea chlororhynchos) or Black-browed (D.melanophrys) are seen. The Wandering (D.exulans), Grey-headed (D.chrysostoma) and Shy Albatrosses (D.cauta) have also been recorded on the island. 5.6 Marine Mammals Two species of pinniped breed in this region: the rare Australian Sea Lion (Neophoca cinerea) and the New Zealand Fur Seal (Arctocephalus forsteri). Of particular significance in this region is the Pages in Backstairs Passage, which comprise the largest breeding colony for sea lions in Australia (and the world). In this region, breeding colonies occur on North Pages Island (310 pups, estimated population 1,491), South Pages Island (260 pups, estimated population 1,251) and the southern coast of Kangaroo Island, particularly Seal Bay (180 pups, estimated population 866). Such diversity, over a relatively small geographic range, is in part due to the wide variety of aquatic habitats found along the island's extensive coastline, and also, the island's close proximity to the South Australian mainland (Glover 1979). Well represented taxonomic groups include the families, Sygnathidae (Pipefishes, Pipehorses, Page 204 KANGAROO ISLAND COAST Together, the Pages and the south coast of the Kangaroo Island comprise two of the three major breeding sites for the rare Australian Sea Lion in South Australia (Robinson & Dennis 1988, Gales et al. 1994), and represent 30% of the Australian or world population of 12,400 for this species (Gales et al. 1994). The southern and western coasts of Kangaroo Island comprise the second largest breeding area for New Zealand Fur Seals in South Australia (after the Neptune Isles). Major breeding sites for fur seals occur at Cape Gantheaume (525 pups, estimated population 2,573), North Casuarina (442 pups, estimated population 2166) and Cape du Couedic (477 pups, estimated population 2,337) (Robinson & Dennis 1988, Shaughnessy et al. 1994). Together, these colonies comprise an estimated 7076 individuals, representing some of the major breeding sites for Fur Seals in South Australia (ie. 26% of the SA population), along with the Neptune Islands (estimated population of 16,886) and Liguanea Island (estimated population of 2,720). Several species of whales frequent the waters around Kangaroo Island and Encounter Bay, and strandings also occur occasionally. In particular, the endangered Southern Right Whale (Eubalaena australis) appears regularly in the winter months during its northward migration from Tasmanian waters to the waters at the Head of the Great Australian Bight. Along Encounter Bay in particular, the whales can be easily from shore. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Backstairs Passage The Backstairs Passage region is unparalleled in it’s diversity of marine invertebrate assemblages and is one of the richest areas for sessile invertebrate fauna in South Australia (Dr Scoresby Shepherd, SARDI, pers.comm.). Strong current flows in the narrow Passage provide optimal conditions for filter-feeding organisms and many organisms, particularly sponges and bryozoans, reach very large proportions and also, importantly, outcompete plant communities in colonising shallow reefal areas in high current regions. The deep water (ie. 75 m) sessile invertebrate fauna of the Passage is of national importance with regard to the diversity of brachiopods (Dr Scoresby Shepherd, SARDI, pers.comm.), and possibly, global importance if records of stalked crinoids by the SA Museum (ie. Dr J Mitchell) are confirmed. The Snapper Point region (including Cable Hut Bay) is of particular significance within Backstairs Passage. Reef communities extend from the shoreline out to 500-700 from the rocky headlands and form habitat for a diverse, shallow water, animal-dominated community (ie. 15 metres and deeper) which is usually found in much deeper waters (50-70 metres). Within the Passage, this community is found in a rocky channel at 75m. This is the first shallow water record of this rich, deep water sessile marine invertebrate community in South Australia, and is also the only recorded site in South Australia where this community type is accessible on SCUBA. The community is characterised by very large filter-feeding organisms, particularly very large sponge, bryozoans and crinoid assemblages. The region which contains these assemblages appears to be restricted to the southern part of the Backstairs Passage (ie. the Kangaroo Island coast). The shallow water, sponge-bryozoan-crinoid community is highly localised within the southernwestern part of the Passage (ie. Snapper Point region). Australian Sea Lions - Seal Bay Seal Bay is an important area for a large breeding colony of the rare Australian Sea Lion. Its importance is reflected by its status as both a conservation park and an aquatic reserve. It is also one of the major tourist destinations on Kangaroo Island, and for South Australia. The south coast of the Kangaroo Island, particularly Seal Bay, comprises the third largest breeding area for the rare Australian Sea Lion in South Australia, after the Pages and Dangerous Reef (Robinson & Dennis 1988, Gales et al. 1994). The population on the southern coast of Kangaroo Island, particularly Seal Bay, is estimated at 866 (ie. 180 pups), and represents a significant proportion of the estimated Australian or world population of 12,400 for this species (Gales et al. 1994). A total of 331 adults and 156 pups were recorded at Seal Bay in 1977 (Robinson & Dennis 1988), while 427 adults and 162 pups were recorded in 1990 (Gales 1990). Page 205 KANGAROO ISLAND COAST Coastal Wetlands of National Importance New Zealand Fur Seals – Cape Gantheaume, Cape du Couedic, North Casuarina The southern and western coasts of Kangaroo Island comprise the second largest breeding area for New Zealand Fur Seals in South Australia (after the Neptune Isles). Major breeding sites for fur seals occur at Cape Gantheaume (525 pups, estimated population 2,573), North Casuarina (442 pups, estimated population 2,166) and Cape du Couedic (477 pups, estimated population 2,337) (Robinson & Dennis 1988, Shaughnessy et al. 1994). Together, these colonies comprise an estimated 7,076 individuals, representing some of the largest breeding sites for Fur Seals in South Australia (ie. 26% of the SA population), and Australia, along with the Neptune Islands (estimated population of 16,886) and Liguanea Island (estimated population of 2,720). A Directory of Important Wetlands in Australia (ANCA 1996) list the following coastal wetlands of national importance along the Kangaroo Island Coast: 1 2 3 4 5 6 7 8 American River Wetland System Busby and Beatrice Islets Cygnet Estuary D’Estrees Bay Flinders Chase River Systems (NW River, Breckneck River, Rocky River) Grassdale Lagoons (SW River) Lake Ada Lashmar Lagoon (Chapman River, Antechamber Bay) Encounter Bay Pages Conservation Park The Pages represent the largest breeding colonies of the rare Australian Sea Lion in South Australia, and the world. The Pages consists of two small islands and a rocky reef in Backstairs Passage. Breeding colonies occur on North Pages Island (310 pups, estimated population 1,491) and South Pages Island (260 pups, estimated population 1,250) (Gales et al. 1994). Together, these comprise a major proportion of the Australian (and world) population (estimated at 12,400 individuals). In 1990, 595 sea lions (including 280 pups) were recorded on North Page, 417 seals (242 pups) on South Page, and 140 were recorded on SW Pages Reef, which is a recognised haul out site (Gales 1990). Metamorphosis of the sediments deposited during the latter part of the Cambrian Period produced phyllite rock of the Brukunga Formation, which now forms the rock of the islands. North Page (24 m high) and South Page (20 m high) are the two main islands and both have precipitous slopes and deep chasms. The tops of the islands are relatively flat with small soil pockets. The islands can be considered remote and the only reliable means of access is by helicopter. The islands feature in the Kaurna Aboriginal legend which describes the journey of the totemic being Ngurunderi as he pursued his unfaithful wives. Upon catching them he transformed them into the islands. A reed basket carried by the younger wife was transformed into a nearby reef. The Pages is an important area for sea birds and seals - a fact recognised by their declaration as part of a Bird Protection District under the Birds Protection Act in 1900. The Pages Conservation Park (20 ha) is now under the control of the National Parks and Wildlife Service. − Macroalgae assemblages, Whales, Little Penguins, Leafy Seadragons, Seabirds, Hemichordates. Coastal Wilderness Areas The Kangaroo Island coast has some of the most spectacular coastal wilderness and visual amenity along the South Australia coast, and is home to all 5 of South Australia’s Wilderness Protection Areas, declared under the Wilderness Protection Act 1992 (to protect natural and remote wilderness areas). These areas include: − Cape Bouguer Wilderness Protection Area (5,530 ha). − Cape Gantheaume Wilderness Protection Area (20 100 ha). − Cape Torrens Wilderness Protection Area (751 ha). − Ravine des Casoars Wilderness Protection Area (41,320 ha). − Western River Wilderness Protection Area (2,373 ha). Page 206 KANGAROO ISLAND COAST 1.2 Physical 2 Murray Submarine Canyons The Murray Submarine Canyons are giant submarine canyons 60 km south of southern Kangaroo Island. Some of these huge clefts are larger than the Grand Canyon in the U.S.A. They wind their way from the outer continental shelf to oceanic depths of approximately 4,600 m. They may be important as a valuable source of upwelling water which contributes to the nutrients of the food chain (Von der Borch 1979). The sediments of the canyon walls could also contain a record of the major geological changes that occurred during the evolution of the South Australian continental margin. GLORIA sidescan sonar images reveal steep, rugged topography that would probably contain some unique, little known ecosystems (Von der Borch pers. comm.). "Geological Monuments” There are 16 areas of geological significance on Kangaroo Island which are associated with the coastline or offshore waters. These areas have been identified and recognised as "geological monuments" by the South Australian Museum and the Geological Society of Australia, and include the following sites: 1. Kingscote (foreshore) 2. Old Government Quarry, Kingscote 3. The Big Gully 4. Emu Bay (Cape D'Estaing) 5. Smith Bay (glacial pavements) 6. Stokes Bay 7. Harveys Return 8. West Bay 9. Cape du Couedic 10. Remarkable Rocks 11. Point Ellen, Vivonne Bay 12. Cape Willoughby (granite contact) 13. Alex Lookout to Snapper Point 14. Christmas Cove, Penneshaw 15. Willson River 16. D'Estrees Bay In addition, Ravine des Casoars is also considered to be a significant geological site.45 Further details of these areas are supplied in the relevant biounit sections below. SIGNIFICANT CULTURAL HISTORICAL FEATURES AND The following description of Aboriginal and European history along the Kangaroo Island coast is necessarily brief and selective. The aim is to give the province a historical perspective with emphasis on coastal and maritime history. Only details of Aboriginal historical and cultural sites that have been published in the available literature are described. Aboriginal sites, objects and remains are protected under the South Australian Aboriginal Heritage Act (1988), and a register of such sites, objects and remains is kept with the Aboriginal Heritage Branch of the South Australian Department of Environment and Planning. 2.1 Aboriginal At the time of its discovery by Europeans, Kangaroo Island was uninhabited by Aborigines. Archaeological sites show that Kangaroo Island was occupied at several dates until as recently as 4,300 years ago. The geologist Howchin found the first prehistoric stone tools near the shore of Murray Lagoon in 1903. More hammer stones and cutting pebbles were found by Tindale and Maegraith in 1931, and Tindale continued exploration until the 1960s. Over 100 sites were found, many containing large numbers of massive stone tools made from beach cobbles and blocks of stone. Tindale named the stone industry `Kartan' after the Ramindjeri name `Karta' for Kangaroo Island. Kangaroo Island was known by the mainland Aboriginals as `Karta Island of the Dead', because it is where Ngurunderi, the great spirit ancestor, ended his long voyage down the Murray River and along the South Coast in pursuit of his unfaithful wives. 2.2 European First Discoverers Captain Matthew Flinders sighted Kangaroo Island in 1802, in what was probably the first European sighting of the island. The name was chosen because of the abundant kangaroos on the island that provided the crew with fresh meat. The French navigator Captain Nicolas Baudin was the first to circumnavigate the island in 1802, just after Flinders' visit. Following the voyages of Flinders and Baudin, the island was occasionally inhabited by sealers, whalers, escaped convicts and sailors seeking refuge. Formal settlement became more definite in the early 1830's following the explorations by Captain Charles Sturt and Captain Collett Barker, and in 1836 a whaling settlement at Nepean Bay was established. 45 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 207 KANGAROO ISLAND COAST The Encounter Bay area is a significant area for European History in South Australia. As well as being the site where Captain Matthew Flinders met the French navigator Baudin in 1802, it was also a site of early settlement and their first industy whaling. Cape Jervis is also a significant site for European history and was also a site for the whaling industry from the 1840's til 1855. Shipwrecks − Marine Sanctuaries None − − − − Netting Closures Kingscote Spit Bay of Shoals American River – Eastern Cove Kangaroo Island Rivers Wrecks in excess of 75 years old in Commonwealth waters are automatically protected by Commonwealth legislation, ie. Historic Shipwrecks Act 1976. Other wrecks may be protected if of significant value. Wrecks situated in State waters may be protected by proclamation under the State legislation, ie. Historic Shipwrecks Act 1981. The rugged and precipitous coastline of Kangaroo Island has claimed many ships with some 57 known shipwrecks between 1847 and 1985. Cape Willoughby was the first lighthouse to be built in South Australia in 1852. The west coast of Kangaroo Island in particular, is an area of significant historical and cultural value, due primarily to the number and density of shipwrecks and the associated large loss of life (B. Jefferies, State Heritage Branch, pers.comm.). Significant wrecks in this area include the `Loch Sloy', `Loch Vennachar', `Montebello', `Mars', `Emily Smith' and `Portland Maru'. 3 CURRENT CONSERVATION STATUS OF THE KANGAROO ISLAND COAST As with the other coastal provinces of South Australia, the majority of MPAs in this region comprise `netting closures'. However, many of these areas have generally not been formally recognised as MPAs by some authors (see Ivanovici 1985). Three Aquatic Reserves have been declared in this province, two on Kangaroo Island and one in Encounter Bay. No Marine Parks have been declared in this region. Present MPAs in this region include: − − − − Marine Reserves American River Aquatic Reserve (1,525 ha) Seal Beach Aquatic Reserve (1,140 ha) West Island Aquatic Reserve (65 ha) (mainland) Marine Parks None Page 208 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS XIV MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF NEPEAN AND BACKSTAIRS BIOUNITS This coastal region comprises 2 biounits: the inshore coastal Nepean Biounit, and the offshore Backstairs Biounit. The Nepean Biounit extends from North Cape to Cape Willoughby and covers an area of 102 304 ha and a coastal distance of approximately 114 km. It faces into Backstairs Passage and Investigator Strait. The Backstairs Biounit is defined by the 50 metre bathymetric contour and covers an area of 35,911 ha, encompassing the waters of the Backstairs Passage and the Pages offshore islands. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY With the exception of Backstairs Passage and `The Pages', this biounit has a predominantly low wave energy regime. This is due to its northern aspect. In the Bay of Shoals, a 10 km shoal that extends south east from Cape Rouge, effectively blocks waves from the gulf, creating low energy conditions inside the Bay. In other parts of the biounit, the North East Dudley Peninsula is a more moderate wave energy coast, whilst `The Pages' experience moderate to high wave energy conditions. American River is a tidal channel that links Pelican Lagoon to Eastern Cove. The channel is confined by the Cambrian sediments and Holocene beach sandflat deposits along the western shore and the calcarenite of Picnic Point and Holocene beach ridges and sandflats between Saphiretown and Strawbridge Point along the eastern shore. The lagoon itself occupies a shallow depression and is surrounded by low calcarenite scarps, including several low islands also formed of calcarenite. The tidal flats are sandy mud. 3 BIOLOGY Major Inshore Habitats 2 GEOLOGY AND GEOMORPHOLOGY 46 COASTAL The Bay of Shoals is dominated by intertidal to shallow subtidal sand deposits and a small section of cliffs, between North Cape and Point Marsden. Areas of low energy coastline that are subject to tidal inundation such as the southwest section of the Bay of Shoals are considered unusual on the island. Within Western Cove there are extensive Holocene beach ridges, samphire flats and sandflats. An extensive wetland area is associated with the mouth of Cygnet River, in the southwestern corner of Western Cove. − Major intertidal habitats in the region include low rocky cliffs and shores, sheltered bays and estuaries (ie. intertidal mud and sandflats) and sandy beaches. − Of the total inshore subtidal habitats mapped in the Nepean Biounit (46,876 ha), seagrass meadows comprise 23,229 ha (49.6%), sandy bottoms comprise 21,523 ha (45.9%), and reefs comprise 2,124 ha (4.5%). Of the total inshore subtidal habitats mapped in the Backstairs Biounit (1,282 ha), seagrass meadows comprise 668 ha (52.1%), reefs comprise 527 ha (41.1%), and sandy bottoms comprise 87 ha (6.8%). Eastern Cove is flanked on either side by dominant cliffs and headlands with the southern shoreline being predominantly sandy beaches. North East Dudley Peninsula has very stable rocky cliffs. Apart from minor deposits in Christmas Cove and Hog Bay, Holocene sedimentation is restricted to Antechamber Bay. There are two wide sandy beaches on the peninsula and a wetland area located at the northern end of Antechamber Bay. Major Benthic Communities • − Macroalgal The rocky shores and reefs of the northeast coast of Kangaroo Island (particularly east of Kangaroo Head), generally experiences strong tidal currents (through Backstairs Passage). In more sheltered locations (eg. Kangaroo Head), reef areas tend to colonised by species of Cystophora (C.monilifera, C.expansa), Caulocystis ulvifera and Sargassum (S.fallax, S.heteromorphum). 46 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 209 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS While on more exposed shallow shores and reefs (eg. Cable Bay, Snapper Head), reef areas tend to be dominated by more robust brown algae (ie. Scytothalia dorycarpa, Carpoglossum confluens, Ecklonia radiata, Seirococcus axillaris, Acrocarpia paniculata, Carpopeltis) with species of Cystophora (C.moniliformis, C.monilifera) and species of Sargassum (eg. S.fallax, S.hetermorphum) as sub-dominants, with an understorey of Caulerpa, mixed sponges, ascidians and bryozoans and encrusting coralline algae. At deeper depths (ie. >12m), reef areas are colonised by a rich faunal assemblage, dominated by sponges (eg. Thorecta, Dendrilla, Aplysina), soft corals (eg. Capnella), octocorals, gorgonians (eg. Mopsella), large bryozoans (eg. Adeona grisea, Triphyllozoon sp. Celloporaria sp., Orthoscuticella ventricosa) crinoids (eg. Cenolia trichoptera) and other echinoderms (eg. basket stars, brittle stars, sea stars), hydroids, and filamentous red algae. The shallow depth of this community, and also, the diversity and size of the sessile invertebrate fauna, makes this type of marine habitat unique in South Australia. The habitat is most probably a consequence of the strong tidal flows within Backstairs Passage. • − Seagrass Seagrass meadows are extensive in this region, but are largely confined to Nepean Bay (ie. Bay of Shoals, Western Cove, Eastern Cove, Pelican Lagoon), Hog Bay and Antechamber Bay. particularly wit and are restricted to the sheltered embayment of Encounter Bay. In Western Cove considerable seagrass has been lost and replaced by large drifts of the red alga, Chiracanthia arborea. In other areas, sandy sediments are commonly colonised by species of Zostera muelleri (from low tide level to 24m) and Posidonia australis (2-4m) in shallow waters, with P.sinuosa, Amphibolis antarctica, Heterozostera tasmanica, Halophila australis generally occurring in deeper water (3-17m). Other species also colonise sandy sediments, particularly species of Caulerpa (eg. C.cactoides). Hard substrata within the meadows (eg. isolated reefs, rocks) are commonly colonised by large fucoids (Scaberia agardhii, species of Sargassum), and species of red algae, Botrycladia obovata, and Osmundaria prolifera. Rivers/Estuaries − Cygnet River estuary. − American River inlet. Coastal and Offshore Islands (or Reefs) − North Pages, South Pages, Pages Reef (Backstairs Passage). − Busby Islet, Beatrice Islet (Nepean Bay). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance − The Cygnet River estuary has been identified as a wetland of national importance (see ANCA 1996). The region includes the saltmarshes and mudflats of the estuary mouth (and surrounding supratidal flats), and also, the Nepean Bay Conservation Park. The estuary is the largest, freshwater-fed wetland on Kangaroo Island, comprising 850 hectares of low coastal dune, and supratidal and intertidal saltmarshes, saline swamps, sandbars and mudflats, which are seasonally inundated. The Nepean Bay Conservation Park represents the only reserve conserving coastal sandplain habitat on the island. The Cygnet River estuary is an important breeding and feeding refuge area for waterbirds including migratory waders and is also an important nursery area for fish. The extensive wetland at the mouth of the Cygnet River is an important area for wading and aquatic birds and the area has the largest number and highest diversity of birds on Kangaroo Island. Page 210 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS Threatened species of waterbirds in the area include the Hooded Plover, Thinornis rubricollis (Nv, Sv), White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Little Egret, Egretta garzetta (Sv), Musk Duck, Biziura lobata (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), Eastern Reef Egret, Egretta sacra (Sr), Australasian Shoveler, Anas rhynchotis (Sr) (ANCA 1996). A total of 53 species of waterbirds have been recorded in the area: 17 are listed under international treaties. A total of 20 species of waterbird breed in the area, including Yellow-billed Spoonbill, Platalea flavipes, Cape Barren Goose, Australasian Shoveler, Musk Duck, Caspian Tern, Sterna caspia and Fairy Tern. The seabird, Little Penguin, Eudyptula minor, also breeds in the area. The Cygnet River estuary has been extensively modified north of the river by the golf course, effluent ponds and rubbish dump. However, south of the Cygnet River, the estuary area is virtually inaccessible and could be regarded as a wilderness area.47 Lloyd & Balla (1986) considered it to be an area of outstanding environmental value and recommended that it should be given status as a wetland reserve. The Nepean Bay Conservation Park is listed on the Register of the National Estate. − The American River wetland system has been recognised as a wetland of national importance (see ANCA 1996). The wetland system consists of several large, permanently shallow, seagrass-dominated lagoons (Pelican Lagoon) which are connected to the open sea by a narrow channel known as American River. This area and it’s biology is particularly significant as Kangaroo Island is almost devoid of similar low-energy, sheltered tidal habitats. The wetland habitats are conserved in the American River Aquatic Reserve (1,525 ha) and the Pelican Lagoon Conservation Park (366 ha). The lagoons contain eight islets and the shorelines include shelly beaches, and tidal mud and sand flats. The area contains abundant mudflats, intertidal and subtidal seagrass meadows (dominated by Heterozostera tasmanica, Posidonia australis, Halophila australis), and to a lesser extent, subtidal algal beds (dominated by the brown algae, Sargassum biforme and Scaberia agardhii), which are important feeding grounds for waterbirds and provide important refuge, breeding and nursery habitats for many species of fish, crustaceans and invertebrates. Threatened species of waterbirds in the area include Hooded Plover, Thinornis rubricollis (Nv, Sv), Little Egret, Egretta garzetta (Sv), Osprey, Pandion haliaetus (Sv), White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Musk Duck, Biziura lobata (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), Eastern Reef Egret, Egretta sacra (Sr), Australasian Shoveler, Anas rhynchotis (Sr) (ANCA 1996). A total of 56 species of waterbirds have been recorded in the area: 17 are listed under international treaties. A total of 9 species of waterbirds have been recorded breeding in the area, including the Pied Oystercatcher, Haematopus longirostris, Sooty Oystercatcher, H.fuliginosus, Hooded Plover, Red-capped Plover, Charadrius ruficapillus, and Caspian Tern, Sterna caspia. The area is a known nursery area for King George Whiting, Sillaginodes punctata. Fauna in the region include bivalve molluscs, sponges, starfishes, anemones, holothurians, polychaetes, razor fish (Pinna bicolor), crabs and a range of fish species, including sting rays, eagle ray and small sharks (Womersley & Edmonds 1979). Commercial fish species recorded in the area include King George Whiting, Sand Flathead, Yellow-Eye Mullet, Aldrichetta fosteri, Australian Salmon, Arripis truttacea, Southern Sea Garfish, Hyporhampus melanochir, Tommy Ruff, Arripis georgiana, and Squid, Sepioteuthis australis. The area is also important for pods of local Bottle-nosed Dolphins, Tursiops truncatus. − Busby and Beatrice Islets have been recognised as wetlands of national importance (see ANCA 1996). The low-lying islets protrude from a large offshore sand spit, north-west of the township of Kingscote and are conserved in the Beatrice Islet Conservation Park and the Busby Islet Conservation Park. Beatrice island is an unvegetated, mudflat/cocklebed islet that emerges only at low tide and forms part of a larger sand spit. It is an important area for feeding and roosting birds. 47 Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 211 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS Busby Islet is a low vegetated island composed of sand and shell grit and originally declared for the conservation of wildlife habitat. Vegetation includes coastal samphire (Sarcocornia sp.) and Atriplex. Some 28 bird species have been recorded on the island. Threatened species of waterbirds recorded in the area include the White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), and Little Egret, Egretta garzetta (Sv). − A total of 38 species of waterbirds have been recorded in the area: 13 are listed under international treaties. A total of 12 species of waterbird breed in the area, including, large breeding rookeries of Pied Cormorants, Phalacrocorax varius, Little Pied Cormorants, P.melanoleucos, Black-faced Cormorants, P.fuscescens, Australian Pelicans, Pelecanus conspicillatus, and Australian White Ibis, Threskiornis molucca. Both island parks are on the Register of the National Estate. − Lashmar Lagoon and the Chapman River estuary have been identified as wetlands of national importance (see ANCA 1996). The site consists of Lashmar Lagoon, a shallow, freshwater (slightly brackish) lake and the lower reaches of the Chapman River to the river mouth, where it enters the sea at Antechamber Bay. The site is an important feeding and breeding refuge for waterbirds and migratory wader species, and provides a winter refuge for the Hooded Plover, Thinornis rubricollis (Nv, Sv). Threatened species of waterbirds recorded in the area include the Hooded Plover, Little Egret, Egretta garzetta (Sv), Freckled Duck, Stictonetta naevosa (Sv), Musk Duck, Biziura lobata (Sv), Lewin’s Rail, Rallus pectoralis (Sv), Australasian Shoveler, Anas rhynchotis (Sr), Baillon’s Crake, Porzana pusilla (Sr) and Spotless Crake, P.tabuensis. A total of 50 species of waterbird have been recorded in the area: 9 are listed under treaties. A total of 15 species of waterbird breed in the area, including the White-faced Heron, Egretta novaehollandiae, Little Pied Cormorant, P.melanoleucos, Little Black Cormorant, P.sulcirostris, Australasian Shoveler, Musk Duck, Black Swan, Cygnus atratus, Buffbanded Rail, Gallirallus philippensis, and both species of crakes. Fish recorded in the region include the Common Galaxias, Galaxias maculatus (Lloyd & Balla 1986). Offshore Islands of Recognised Conservation Significance − The Pages Conservation Park is home to the largest breeding colonies of the rare Australian Sea Lion in South Australia (and the world). Breeding colonies occur on North Pages Island (310 pups, estimated population 1,491) and South Pages Island (260 pups, estimated population 1,250) (Gales et al. 1994). Together, these comprise a major proportion of the Australian (and world) population (estimated at 12,400 individuals) (Gales et al. 1994). The total population of sea lions on the islands has increased in recent years, from a total of 422 recorded in 1982 (Robinson & Dennis 1988) to 1,012 recorded in 1990 (Gales 1990). In the 1990 census, a total of 595 and 417 sea lions (including 280 and 242 pups) were recorded on North and South Page, respectively (Gales 1990). A further 140 sea lions were recorded on SW Pages Reef, however this is most likely a haul out site (Gales 1990). New Zealand Fur Seals have also been recorded on North Page (Shaughnessy 1990). However it is not a known breeding site for this species. These islands are also an important breeding area for seabirds, as recognised by their declaration as part of a Bird Protection District under the Birds Protection Act in 1900. Other Areas of Recognised Conservation Significance − The Backstairs Passage region is unparalleled in it’s diversity of marine invertebrate assemblages and is one of the richest areas for sessile invertebrate fauna in South Australia (Dr Scoresby Shepherd, SARDI, pers.comm.). Strong current flows in the narrow Passage provide optimal conditions for filter-feeding organisms and many organisms, particularly sponges and bryozoans, reach very large proportions and also, importantly, outcompete plant communities in colonising shallow reefal areas in high current regions. The deep water (ie. 75 m) sessile invertebrate fauna of the Passage is of national importance with regard to the diversity of brachiopods (Dr Scoresby Shepherd, SARDI, pers.comm.), and possibly, global importance if records of stalked crinoids by the SA Museum (ie. Dr J Mitchell) are confirmed. Page 212 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS − The Snapper Point region (including Cable Hut Bay) is of particular significance within Backstairs Passage. Reef communities extend from the shoreline out to 500-700 from the rocky headlands and form habitat for a diverse, shallow water, animal-dominated community (ie. 15 metres and deeper) which is usually found in much deeper waters (50-70 metres). Within the Passage, this community is found in a rocky channel at 75m. This is the first shallow water record of this rich, deep water sessile marine invertebrate community in South Australia, and is also the only recorded site in South Australia where this community type is accessible on SCUBA. The community is characterised by very large filter-feeding organisms, particularly very large sponge, bryozoans and crinoid assemblages. The region which contains these assemblages appears to be restricted to the southern part of the Backstairs Passage (ie. the Kangaroo Island coast). The shallow water, sponge-bryozoan-crinoid community is highly localised within the southern-western part of the Passage (ie. Snapper Point region). − Penneshaw has breeding colonies of Little Penguins. − Nepean Bay Conservation Park. This coastal park represents the only reserved area of coastal sandplain on Kangaroo Island. It is a well vegetated area with low coastal dunes. Some 80 species of birds, 8 species of reptiles and amphibians, and 4 mammal species have been recorded in the park. Tidal flats occur outside the park boundary. The park is on the Register of the National Estate. − Adjacent to the American River Aquatic Reserve is the Pelican Lagoon Conservation Park, comprising 55 hectares of low scrubland and low open scrubland/grassland. Some 115 species of birds, 16 species of reptiles and 8 species of native mammals have been recorded in the park. The park offers attractive views of Pelican Lagoon and American River. The Pelican Lagoon Conservation Park is on the Register of the National Estate. − 1.2 − Between Ballast Head and the American River township, dense coastal vegetation includes Allocasuarina verticillata which is a major feeding and breeding habitat for the Glossy Black Cockatoo, Calyptorhynchus lathami (an endangered species at the State level) and also provides a major component of the habitat for the Beautiful Firetail, Emblema bella (a rare species at the State level). Physical The Bay of Shoals and Nepean Bay differ significantly from each other. Bay of Shoals, being a more confined bay with lower wave energy, has no depositional features apart from the sand/cobble shoals at the entrance. The Nepean Bay, however, has sediments deposited into the bay from the Cygnet River and slightly higher wave energy, and hence shows depositional features such as beach ridges. The two bays are, therefore, considered different from each other, with Bay of Shoals being geomorphologically representative of a low energy, nondepositional bay, and Nepean Bay being geomorphologically representative of a slightly higher energy, depositional bay (D. Fotheringham pers. comm.). Geological Monuments • − Kingscote foreshore: Late Eocene bryozoan limestone exposed in coastal cliffs around the foreshore. Raised beach deposit of basalt pebbles at Rolls Point. A 700 m section of coastal cliffs to the southwest of Kingscote with teaching, recreation and aesthetic value. • − Old Government Quarry, Kingscote: basalt of probable Jurassic age, typical of the Kangaroo Island occurrences, but not found on the mainland. Overlies Permian glacigene and fluvial sediments. The Rock from the quarry was used in Adelaide roads in 18401841. Contained within a 900 metre section of coastal cliffs with historic and scientific value. • − The Big Gully: Early Cambrian fossiliferous strata including White Point Conglomerate, Emu Bay shale and Boxing Bay formation. Includes type section of the last. Site comprises of 2.5 km of coastline with teaching, research and scientific value. Page 213 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS • − Alex Lookout to Snapper Point: sequence of Late Precambrian and Early Cambrian metasediments. The only exposures of certain Precambrian rock on Kangaroo Island. 5 km of coastline with teaching and scientific value. • − Christmas Cove, Penneshaw: Permian glacegene sediments and erratics of glaciates surfaces of Early Cambrian sediments including polymictic conglomerate with teaching and aesthetic value. 2 2.1 OTHER VALUES Commercial Fisheries Fishing is an important industry for all of Kangaroo Island, for both commercial and recreational fishers. Major single species fisheries include the Southern Rock Lobster, Abalone and Western King Prawn. Kingscote and Penneshaw are major ports of landing for both Southern Rock Lobster and marine scalefish. Kingscote has 14 of the 24 Southern Rock Lobster boats operating from this port. American River has only a few boats using this area as their port of landing. Many of the mainland license holders also fish at Kangaroo Island. Western King Prawn This biounit is located within the waters of the Gulf St Vincent prawn fishery, which comprises 10 license holders (ie. boats). All vessels fish within the waters of the Gulf St Vincent and Investigator Strait biounits (ie. Sturt, Investigator, Orontes, Clinton, Yankalilla, Nepean, Encounter, St Vincent). In 1995/96 and 1996/97 a total of 258,459 and 210,581 kg was caught for this fishery, with a total effort of 2,996 and 3,235 hours, respectively (or 11.38% and 10.41% of the total catch for Western King Prawn in South Australian waters). Southern Rock Lobster In 1995/96 and 1996/97 a total of 4 and 3 licensed operators fished in the Nepean Biounit (ie. Fishing Zone 42). In addition, lobster fishing is also present in the waters of north western Kangaroo Island and Backstairs Passage (and also, the southern Fleurieu) (ie. Fishing Zone 44). In 1995/96 and 1996/97 a total of 8 and 6 licensed operators fished in this region (ie. Fishing Zone 44), catching approximately 7,036 and 5,390 kg of lobsters, respectively (or 0.14% and 0.11% of the total catch for Southern Rock Lobster in South Australian waters). Abalone There is limited Greenlip and Blacklip Abalone commercially harvested within the western section of this biounit, (ie. MapCode 32A-C, Nepean Bay, Hog Point to Cape Cassini region). No Greenlip was harvested in this region in 1995/96. Greater quantities of Blacklip Abalone are harvested in the eastern section of this biounit, (ie. MapCode 31A-C, Antechamber Bay to Cape Hart and False Cape, Backstairs Passage region), but due to confidentiality constraints these figures are not available. Marine Scalefish Fisheries During 1995/96 and 1996/97, 33 and 32 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species in the Nepean Biounit region (ie. Fishing Zone 42), respectively. License holders expended approximately 2,030 and 2,139 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 42) represented 84,372 kg in 1995/96 and 221,191 kg in 1996/97(or 0.81% and 2.18% of the total catch for the marine scalefish fishery in South Australian waters). Hand line fishing for King George Whiting occurs around American River, Nepean Bay (including both Western and Eastern Coves) and the Bay of Shoals. Some netting for Garfish and King George Whiting occurs in these areas as well. Dab netting occurs in Western and Eastern Coves for Garfish and a Sand Crab fisher also traps here. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Kingscote: 15 northern zone Rock Lobster, 27 unrestricted marine scalefish, 3 restricted marine scalefish, 1 Abalone. − Penneshaw: 4 unrestricted marine scalefish. − American River: 1 restricted marine scalefish, 1 Rock Lobster. Page 214 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS 2.2 Aquaculture Pacific Oyster rack farming and Blue Mussel longline farming are the major mariculture industries operating in this coastal biounit. At present, there are 6 approved oyster leases, including, 1 lease on the northern side of the Bay of Shoals; 1 lease in the Cygnet River (towards the mouth end); and 2 leases in Western Cove, near the Red Banks (ie. eastern side of Nepean Bay Conservation Park); and 2 leases adjacent to the Cygnet River (in land based ponds). In addition, there are another 11 pending oyster lease applications in this region, including, a further 7 leases in Western Cove (south of the Cygnet River); 2 more leases on the northern side of the Bay of Shoals; 1 lease near Ballast Head; and 1 lease in the Cygnet River. Oyster farming has been trialed in Bay of Shoals on a number of leases and has not proven viable (Gilliland 1996). This region has been identified as a major area for existing and future aquaculture development. The Kangaroo Island Aquaculture Management Plan (Gilliland 1996) proposes the following aquaculture development in the region: − 2.3 − − − Bay of Shoals Zone (3,840 ha of waters of Bay of Shoals and Spit, including waters adjacent Busby Islet Conservation Park) – zoned to trial aquaculture. A total of 30 ha of R&D licenses will be considered in zone, excluding finfish culture, and within 1km of HWM on Busby Inlet, within 500m of `Fannie M’ shipwreck. Eastern Cove Zone (2 450 ha of waters in northern Eastern Cove, from Point Morrison to Ballast Head, east to Kangaroo Head) – zoned to encourage sustainable shellfish longline culture. Licenses will be considered for a total of 200ha of shellfish longline culture in this zone. Western Cove Aquaculture Zone (375 ha of coastal waters east of Nepean Bay Conservation Park) – zoned to encourage sustainable intertidal oyster culture. Licenses will be considered for a total of 70ha of intertidal oyster culture in this zone. American River Aquaculture Zone (65 ha of intertidal waters between Ballast Head and American River) – zoned to encourage sustainable intertidal oyster culture. R&D licenses will be considered for a total of 30ha of intertidal oyster culture in this zone. Recreation and Tourism Fishing − Kingscote: jetty and boat fishing. Major species: King George Whiting, Black Bream, Yelloweye Mullet, Australian Salmon, Snapper, Snook, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket and Calamari. − American River: boat fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Garfish, Tommy Rough and Calamari. − Penneshaw: boat and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Sweep, Garfish, Tommy Rough, Calamari, Trevally and Toothbrush Leatherjacket. − Pennington Bay: boat fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Sweep, Tommy Rough, Trevally, Toothbrush Leatherjacket and Silver Drummer. − There is an artificial reef located off Kingscote (consisting of 450 rubber tyre modules). Nepean Bay Policy Area − Nepean Bay Aquaculture Zone (26,880 ha of offshore waters of Nepean Bay) – zoned to provide for future interest in aquaculture. Licenses will be considered for a total of 250ha of aquaculture in this zone, comprising a total of 200ha of longline shellfish culture, in this zone. Tourism − Bay of Shoals: boating, fishing, historic area (Reeves Point) − Western Cove and Kingscote: boating, jetty fishing, historic area, scenic area. − Eastern cove: boating, jetty fishing, camping, historic area, scenic area. − Penneshaw: penguin `parades', historic area, camping, jetty fishing, boating. − Penneshaw to Cape Willoughby: scenic area, historic area, camping, fishing, boating. Page 215 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS − 2.4 − − 2.5 SCUBA diving: there are many popular diving locations in this region, particularly near Kangaroo Head and Penneshaw. Several of these are utilised by local dive operators for training (eg. Adventureland Diving). The Penneshaw jetty is a very popular local diving spot for training novice divers, night diving and underwater photography. Strong tidal flows in the area have produced a wide range of marine life on the pylons, particularly very large gorgonian or fan corals. Scientific Research and Education Pelican Lagoon Wildlife Research Centre is situated on the shores of Pelican Lagoon (American River inlet), and provides research facilities and accommodation for a wide range of national and international scientists. The field centre is globally recognised for the range of research facilities and activities conducted, and also, the diversity of natural habitats and biota available for scientific research. Studies encompass a wide range of ecological and physiological projects on the terrestrial fauna and flora (particularly mammals and reptiles), to more recently, studies on the marine habitats of Pelican Lagoon, as part of a `CoastCare’ community grant. Pelican Lagoon has been the site of marine research investigations by the University of Adelaide (and more recently, the SA Herbarium), since the 1940s. American River inlet, and the coastal areas surrounding Kingscote and Penneshaw, have been regular research sites since the early 1940's for marine algal collections and intertidal studies (see Womersley 1950, 1956, Womersley & Edmonds 1958, 1979). Adjacent Land Use National and Conservation Parks − − − − Nepean Bay Conservation Park (30 ha) (SANPSW 1987). Pelican Lagoon Conservation Park (365 ha) (SANPWS 1987). Dudley Conservation Park (1,122 ha) (SANPWS 1987). Lashmar Conservation Park, Antechamber Bay (188 ha). Offshore Island Parks: − The Pages Conservation Park (15 ha). − Busby Islet Conservation Park (10 ha). − Beatrice Islet Conservation Park (10 ha). Agriculture/Industry The majority of land surrounding the eastern portion of Eastern Cove is used for rural purposes, whereas the southern portion contains a significant belt of vegetation. A major shipping jetty is located at Ballast Head in connection with the gypsum mining industry which ceased operation in 1992. On the Kingscote foreshore there is an old basalt quarry and wharf. Major sources of point-source pollution in this biounit include: a major storm water outfall near the Kingscote Yacht Club building; a septic tank overflow outlets along the foreshore north of Pelican Point; septic overflow pipes at American River from the hotels and motels along the coast. 48 Urban Centres − Kingscote (population 1,450). Kingscote also has a permanent coastal mooring facility for recreational craft. − Penneshaw (population 300). − American River (population 250). American River also has a permanent coastal mooring facility for 81 recreational craft. Whilst Penneshaw and American River are relatively small urban centres, they are important tourist destinations and hence experience considerably higher populations during the warmer months of the year. 2.6 Features Significant Cultural or Historical Aboriginal − Reeves Point contains land that has been proclaimed an Historic Reserve under the Aboriginal and Historic Relics Act 1975. 48 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 216 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS European − − − The first band of pioneers landed from the Duke of York at Kingscote on 27th July 1836. Reeves Point, the actual site of the first landing and South Australia's first official settlement, is of great historical significance and archaeological value. Reeves Point is registered on the State Heritage Register, Register of the National Estate and is classified on the National Trust. American River is one of the oldest known areas of South Australia. It was originally called Pelican Lagoon by Matthew Flinders in 1802 because of the large number of pelicans found there. There are numerous heritage items within the township and on the coast. These include, the Anchor Memorial on the foreshore, a cairn on the site where the 40 ton schooner, `Independence', was constructed from native pine in 1803 by Americans, the Muston jetty ruins on the western shoreline of Pelican Lagoon and the Matthew Flinders Cairn situated in the south western corner of Pelican Lagoon. There are also several heritage sites within the existing Pelican Lagoon Conservation Park. The lagoon itself is considered to be of State heritage significance due to its variety of historical associations relating to initial contact and primary industries and is on the Register of the National Estate. Kangaroo Head is where Flinders landed and from which he saw and named Mount Lofty on the mainland. Christmas Cove was chartered and named by Flinders in 1802. As the first documented landfall on the island by Flinders, Christmas Cove is a site of high memorial value and is one of the historically significant natural coastal features in the State. The wreck site lies in 2-3 metres of water in a slight sand depression but only a small amount of the surviving hull structure is visible above the seabed. − `Fannie M’, lost in 1885 (off the Bay of Shoals), and is protected under Commonwealth legislation. 3 CURRENT CONSERVATION STATUS OF THE NEPEAN AND BACKSTAIRS BIOUNIT − Marine Reserves American River Aquatic Reserve (1,525 ha) − Marine Parks None − Netting Closures Kingscote Spit (waters enclosed by lines from Cape Rouge to south to the The Bluff then to Kingscote jetty, and then around Kingscote Spit to Point Marsden). − Bay of Shoals (all waters west of the line from Cape Rouge and The Bluff are closed from 1 January to 31 March every year). − American River – Eastern Cove (all waters south a line from American Beach to western shore of Eastern Cove, approximately one nautical mile south west of Ballast Head jetty). − Kangaroo Island Rivers (Chapmans, Harriet, Eleanor, Western and Middle Rivers and all waters within a 50 metre radius of the mouths of those rivers). 4 AREAS OF HIGH CONSERVATION VALUE IN THE NEPEAN AND BACKSTAIRS BIOUNITS 49 − The Penneshaw jetty is also a site of historical significance. Shipwrecks − 49 `Robert Burns' was built as a fore and aft schooner at Long Bay, Hobart, Tasmania in 1857. It went ashore on the sand spit in Nepean Bay in 1908 when the master confused the leading lights on the shore for those of the Ozone Hotel. From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Ironstone Point – Antechamber Bay − Prime IUCN Conservation Values: rare and threatened species/habitats, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to humaninduced change), biogeographic (high tidal flow environment, rare shallow-water sponge communities, geological monument-Alex Lookout to Snapper Point), ecological (representative habitats, soft bottom spongeascidian communities, seagrass meadowsPage 217 KANGAROO ISLAND COAST – NEPEAN AND BACKSTAIRS BIOUNITS Antechamber Bay, high diversity of marine flora and fauna-brachyiopod fauna, rare and threatened species-Hooded Plover, Little Egret, Baillons Crake, Spotless Crake, breeding colonies of White-faced Heron, Little Pied Cormorant, Little Black Cormorant, crakes), economic (fisheries-Western King Prawn, Blacklip Abalone), social (recreation, tourism, SCUBA diving), national (Wetland of National Importance - Lashmar Lagoon and Chapman River estuary), practicality (insulation, accessibility, compatibilityadjacent to Lashmar Lagoon). American River − Prime IUCN Conservation Values: rare and endangered species/habitats, research, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subjected to human-induced change), biogeographic (representative habitats), ecological (ecological integrity, extensive seagrass meadows, nursery, feeding, and breeding for fish and crustaceans-eg. King George Whiting, rare and threatened species– Sygnathids, waterbirds-Hooded Plover, Little Egret, Osprey, White-bellied Sea Eagle, Cape Barren Goose, Eastern Curlew, Fairy Tern, Eastern Reef Egret, Australasian Shoveler, breeding colonies of Pied Oystercatcher, Sooty Oystercatcher, Hooded Plover, Redcapped Plover, Caspian Tern), economic (fisheries-King George Whiting, Southern Sea Garfish), social (recreation, tourism, European heritage-American River, Pelican Lagoon), scientific (Pelican Lagoon Research Centre), national (Wetlands of National Importance and Register of the National Estate-American River Aquatic Reserve, Pelican Lagoon Conservation Park), practicality (accessibility, insulation, compatibility-adjacent to Pelican Lagoon Conservation Park, American River Aquatic Reserve). Lions), national (Register of the National Estate - Pages Conservation Park), practicality (insulation, compatibility-adjacent to Pages Conservation Park). Bay of Shoals - Western Cove − Prime IUCN Conservation Values: biodiversity, rare and threatened species/habitats, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (representative habitats), ecological (ecological integrity, extensive seagrass meadows, key nursery, feeding and breeding area for fish and crustaceans, significant breeding area for seabirds and waderbirds-Pied Cormorants, Little Pied Cormorants, Black-faced Cormorants, Australian Pelicans, Australian White Ibis, Yellow-billed Spoonbill, Cape Barren Goose, Australasian Shoveler, Caspian Tern, Fairy Tern, Little Penguin, rare and threatened fauna-Hooded Plover, Whitebellied Sea Eagle, Cape Barren Goose, Little Egret, Eastern Curlew, Fairy Tern, Eastern Reef Egret), economic (marine scalefish fisheries-King George Whiting, Southern Sea Garfish), social (recreation, tourism, shipwrecks-`Robert Burns’, `Fannie M’), national (Wetlands of National ImportanceCygnet River estuary, American River wetland system, Busby and Beatrice Islets, Register of the National Estate–Nepean Bay Conservation Park, Busby and Beatrice Islets Conservation Parks), practicality (accessibility, compatibility-adjacent to Nepean Bay Conservation Park, Busby Islet and Beatrice Islet Conservation Parks). Pages Islands − Prime IUCN Conservation Values: rare and threatened species/habitats, research, biodiversity (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (representative habitats), ecological (high biodiversity, reef habitats, rare and threatened fauna – largest breeding colony of Australian Sea Lions in the world, haul out site for New Zealand Fur Seals, breeding colonies of Little Penguin, Crested Tern), economic (fisheries-Southern Rock Lobster, Abalone), social (recreation), scientific (research/monitoring-Australian Sea Page 218 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT XXV MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE GANTHEAUME BIOUNIT From Cape Willoughby to Cape Borda, this biounit covers an area of 167,363 ha and encompasses 51% of the Kangaroo Island shoreline (232 km). It faces south into the Southern Ocean. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY This section of Kangaroo Island by virtue of its southern and westerly aspect, contains all of the high wave energy areas of the island. Most of this coastal region is fully exposed to the Southern Ocean, experiencing strong prevailing southerly and southwesterly winds which result in a heavy surge or swell environment, with waves up to 2m high. Lower energy areas occur only in the east-facing D'Estrees Bay. 2 GEOLOGY AND GEOMORPHOLOGY 50 COASTAL Calcarenite blankets all of the southern and western fringe of the island. The coastline is characterised by bedrock headlands, extensive bedrock and/or calcarenite cliffs and shore platforms, with a few Holocene beach deposits. All beaches and cliffs are capped and backed by dunes. Lower energy Quaternary beach-foredune ridges only occur in D'Estrees Bay. Around Cape Willoughby, granite headlands reach up to 100 m high and slope moderately toward the coast. At Cape Hart Conservation Park, the granites are replaced by Middleton sandstone which forms 40 to 80 metre high cliffs fronted by 40 to 100 m wide supratidal horizontal shore platforms. There is also a shingle beach in the Cape Hart Conservation Park. Stable dune calcarenite scarped and fronted by intertidal shore platforms dominates the coastline from False Cape to Cape Tinline. Most of the cliffs are capped by stable Holocene cliff top dunes. Wave energy is highest in the east area producing high energy intermediate beaches and surf zones often containing reefs. The energy gradually declines to the west, producing current generated sand waves in D'Estrees Bay. Pleistocene dune transgressions that have lithified into dune-calcarenite cliffs and shore platforms, and Holocene dune transgressions that appear in a few high energy beaches dominate the coast from Cape Linois to Bales Beach. Vivonne Bay and Bales Beach represent one of the few remnants along the south coast of the once extensive beach-dune systems. The Eleanor and Harriet Rivers reach the coast at Vivonne Bay, where they are often dammed by a berm resulting from the infrequent flow of the rivers and the high waves at the coast. Brackish lagoons lie in lee of the berm. Approximately 8 km of eroding dune calcarenite cliffs and shore platforms separate Vivonne Bay and Seal Beach. The Cape Kersaint section of coast is dominated by Pleistocene calcarenite cliffs 20 to 70 m high and extending inland between 1 and 5 km. Wide sloping supratidal bedrock shore platforms occur in front of the cliffs. The Stun'sail Boom River empties out at the coast on the eastern side past Kelly Hills Conservation Park. Its mouth is usually blocked by a 150 m long beach, forming a brackish lagoon. Hanson Bay is similar to the other south coast sections of substantial Holocene dune transgression, with cliffs ranging from 30 to 60 m and fronted by wide intertidal shore platforms. Cape Younghusband to Cape du Couedic is mainly granite headlands, which have been blanketed by multiple episodes of Pleistocene dune transgression. The dunes are highest in the west where they reach altitudes of 150 m, decreasing in elevation and thickness eastward. At the coast the highest dune calcarenite cliffs and escarpments are between Cape du Couedic and Kirkpatrick Point where they reach elevations of 130 m. The 34 km section of coast from Cape Bedout to Cape Borda is cliffed throughout (except for four river mouths), with cliffs averaging 70 m in height and generally increasing in height northward from 30 to 50 m to 100 to 130 m by Cape Borda. The four rivers empty out at the coast at beaches that are susceptible to high wave attack and overwashing aeolian processes. 50 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 219 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT 3 BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include mostly exposed rocky cliffs, bays and sandy beaches. − Of the total inshore subtidal habitats mapped in the biounit (52,641 ha), reefs comprise 31,857 ha (60.5%), sandy bottoms comprise 19,521 ha (37.1%), and seagrass meadows comprise 1,263 ha (2.4%). • Seagrasses − Seagrass meadows are sparse in this region and are restricted to the shallow, sheltered regions of D’Estrees Bay (Pennington Bay) and Vivonne Bay. Sandy sediments are commonly colonised by species of Posidonia (P.sinuosa, P.angustifolia), and Amphibolis antarctica. In Pennington Bay and Point Tinline, Posidonia robertsoniae occurs. On exposed coasts (eg. Seal Bay, Vivonne Bay, Cape Hart, Cape Gantheaume, Cape Kersaint, Hanson Bay, West Bay), species of Caulerpa (C.longifolia, C.brownii, C.flexilis, C.obscura, C.scapelliformis, C.simpliuscula) tend to dominate the sand-covered reefs and sandy areas. Major Benthic Communities • − Macroalgal The rocky shores and reefs of the southern and western coast of Kangaroo Island, generally experience strong swells and high wave exposure. Shallow, sand covered, exposed reefs tend to dominate this region. In areas with heavy granite boulders (eg. Cape Kersaint, West Bay), hard substrata is commonly dominated by large fucoid brown algae (ie. Scytothalia dorycarpa, Carpoglossum confluens, Seirococcus axillaris, Acrocarpia paniculata) with species of Cystophora (C.moniliformis, C.retorta). Limestone reefs tend to be dominated by species of Caulerpa (C.longifolia, C.flexilis), with species of Sargassum (S.fallax, S.sonderi), Melanthalia and species of Cystophora (C.moniliformis, C.retorta, C.grevillea, C.platylobium, C.pectinata), or large mixed red algal assemblages (ie. Osmundaria prolifera, Callophyllis, Phacelocarpus, Plocamium), Homeostrichus sinclairii and coralline algae (eg. Haliptilon, Metagoniolithon). Species of Caulerpa in this region, tend to form major communities, codominating with fucoid and red algal communities in sand-covered reefal and boulder habitats. Rivers and Estuaries − Stun'sail Boom National Park). − Small estuarine wetland associated with the mouth of the Willson river. − Small estuaries at Breakneck, Sand and Rocky Rivers (Flinders Chase National Park). − Small estuaries at Eleanor, Harriet and South West Rivers. River (Flinders Chase MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance − D’Estrees Bay has been identified as a wetland of national importance (see ANCA 1996). The site, from Shag Rock to 8km south of Point Tinline, occupies the southern part of D’Estrees Bay and provides an important feeding grounding for waterbirds, particularly migratory waders. Page 220 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT Threatened species recorded in the area include, the Hooded Plover, Thinornis rubricollis (Nv, Sv), Osprey, Pandion haliaetus (Sv), Fairy Tern, Sterna nereis (Sv), and the Eastern Reef Egret, Egretta sacra (Sr) (ANCA 1996). A total of 27 waterbirds have been recorded in the area: 10 are listed under international treaties. A total of 6 species have been recorded breeding in the area: including the Osprey, Pied Oystercatcher, Haematopus longirostris, Sooty Oystercatcher, H.fuliginosus, Hooded Plover, Red-capped Plover, Charadrius ruficapillus and Caspian Tern, Sterna caspia. The southern end of the Bay is included in the Cape Gantheaume Conservation Park. Cape Gantheaume Conservation Park lies within the Gantheaume Wilderness Protection Area proclaimed under the Wilderness Protection Act 1992. − The river systems of Flinders Chase National Park (ie. North West River, Breakneck River, Rocky River) has been identified as a wetland of national importance (see ANCA 1996). The rivers combined represent an unique ecosystem in South Australia, and are the best examples of pristine river systems and plateau swamps in South Australia (ANCA 1996). The catchments of Rocky River and Breakneck River are the only undisturbed river catchments in South Australia. Threatened flora in the area include, the Kangaroo Island Daisy, Achnophora tatei (Sr) and Port Lincoln Mallee, Eucalyptus lansdowneana spp. lansdowneana (Sr). Threatened species of waterbirds recorded in the area include the Hooded Plover, Thinornis rubricollis (Nv, Sv) White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Musk Duck, Biziura lobata (Sv), Lewin’s Rail, Rallus pectoralis (Sv), Painted Snipe, Rostratula benghalensis (Sv), Latham’s Snipe, Gallinago hardwickii (Sv), Australasian Bittern, Botaurus poiciloptilus (Sv), Baillon’s Crake, Porzana pusilla (Sr) and Spotless Crake, P.tabuensis (Sr). A total of 35 species of waterbirds have been recorded in the area: 6 are listed under treaties. A total of 6 species of waterbirds breed in the area, including the Cape Barren Goose, Australian Wood Duck, Chenonetta jubata, White-bellied Sea-Eagle, Baillon’s Crake, Masked Lapwing, Vanellus miles, and Red-capped Plover, Charadrius ruficapillus. The Rocky River and Breakneck River support important colonies of Platypus (Sv) in South Australia. The Breakneck River and Larrikin Lagoon lie within the Ravine Des Casoars Wilderness Protection Area proclaimed under the Wilderness Protection Act 1992. − Grassdale Lagoons and the estuary of the South West River are recognised as wetlands of national importance (see ANCA 1996). The site is located within the Kelly Hill Conservation Park, and consists of 2 permanent freshwater lagoons and the down stream portion of the South West River (down to the river mouth at Hanson Bay). The estuary is a winter and rough weather refuge for the Hooded Plover, Thinornis rubricollis (Nv, Sv) and Osprey, Pandion haliaetus (Sv). Two species of threatened plants are recorded in the area: the Kangaroo Island Daisy and Schoenus discifer (Sr). Threatened species of waterbirds recorded in the area include, the Hooded Plover, Osprey, White-bellied SeaEagle, Haliaeetus leucogaster (Sv), Musk Duck, Biziura lobata (Sv), Freckled Duck, Stictonetta naevosa (Sv), Latham’s Snipe, Gallinago hardwickii (Sv), Eastern Reef Egret, Egretta sacra (Sr), and the Australasian Shoveler, Anas rhynchotis (Sr). A total of 51 species of waterbirds have been recorded in the area: 10 are listed under treaties. A total of 11 species of waterbirds are recorded breeding in the area: including, the Little Pied Cormorant, Phalacrocorax melanoleucos, Australian White Ibis, Theskiornis molucca, Chestnut Teal, Anas castanea, Australian Wood Duck, Chenonetta jubata, Musk Duck, Australian Spotted Crake, Porzana fluminea, and Purple Swamphen, Porphyrio porphyrio. The Kelly Hill Conservation Park is on the Register of the National Estate. Most of the park is in the Cape Bouguer Wilderness Protection Area proclaimed under the Wilderness Protection Act 1992. Other Areas of Recognised Conservation Significance − The southern and western coasts of Kangaroo Island, particularly Seal Bay, comprise one of the three major breeding areas for the rare Australian Sea Lion (Neophoca cinerea) in South Australia (after the Pages and Dangerous Reef). The population of the south coast of Kangaroo Island, particularly Seal Bay has been estimated at 866 (ie. 180 pups) (Gales et al. 1994). Page 221 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT Breeding colonies occur at Seal Bay (Pup Cove, Western and Eastern Prohibited Area, and the main beach), and Cape Gantheaume (Robinson & Dennis 1988, Gales 1990). Haul out sites occur at Cape du Couedic, North and South Casuarina, West Bay Island and Cape Bouger (Robinson & Dennis 1988). − − − The southern and western coasts of Kangaroo Island comprise the second largest breeding area for New Zealand Fur Seals (Arctocephalus forsteri) in South Australia (after the Neptune Isles). Major breeding sites for fur seals occur at Cape Gantheaume (525 pups, estimated population 2573), North Casuarina (442 pups, estimated population 2166) and Cape du Couedic (including Admirals Arch, Ladders South, Ladders North, Nautilus Rock, Nautilus North) (477 pups, estimated population 2337) (Robinson & Dennis 1988, Shaughnessy et al. 1994). Together, these colonies on the south coast comprise an estimated 7076 individuals, representing some of the major breeding sites for Fur Seals in South Australia (ie. 26% of the total estimated population of 27,616 in South Australia) - along with the Neptune Islands (estimated population of 16,886) and Liguanea Island (estimated population of 2720). Fur Seals have also been recorded at Cave Point, Cape Bouguer, Seal Beach, South Casuarina, Weir Point, Vennachar Point, Paisley Island and Cape Borda. However no breeding has been recorded at these sites (Shaughnessy 1990). The Seal Beach Aquatic Reserve and Seal Bay Conservation Park provides a sanctuary for the resident Australian Sea Lion colony which represents more than 10% of the total population of the species. Major habitats include sandy beach, offshore reefs, high wave energy coastline and exposed rocky coast. Seal Bay and Cape Gantheaume National Park are on the Register of the National Estate. − Flinders Chase National Park is the largest park on the island. The coast is characterised by high cliffs broken by small sandy bays and estuaries where rivers reach the sea. Native fish found in the rivers include the Mountain Galaxia (Galaxias olidus), Common Galaxias (G.maculatus), and the Climbing Galaxias (G.brevipinnis). Flinders Chase is considered to be one of the few remaining areas of wilderness in South Australia. This park is on the Register of the National Estate. Most of the park is now contained in the Ravine des Casoars Wilderness Protection Area proclaimed under the Wilderness Protection Act 1992. − The Stun'sail Boom River (Flinders Chase National Park) was considered by Lloyd & Balla (1986) to be an area of outstanding environmental value and they recommended that it should be given status as a wetland reserve. − Cape Hart Conservation Park was originally dedicated as a representative sample of coastal vegetation and soils of the southern part of the eastern end of Kangaroo Island. There have been six native mammals recorded in the park. It has impressive coastal cliffs and scenery, and the vegetation consists of open scrub/low shrubland/open heath and low open forest. − Vivonne Bay Conservation bay is an area of outstanding scenic coastal landscape with vegetation not found in other areas. Sixty five species of birds have been recorded in the park. This park is on the Register of the National Estate. − Basement "highs" such as Sanders Bank and Carter Knoll south and east of Kangaroo Island appear to represent zones of vigorous growth of reef flora and fauna, including bryozoans (C.Von der Borch, pers. comm.). Harriet River (Vivonne Bay Conservation Park) was considered by Lloyd & Balla (1986) to be an area of outstanding environmental value and recommended it should be given status as a wetland reserve. Page 222 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT 1.2 − − − Physical The Murray Submarine Canyons are giant submarine canyons 60 km south of southern Kangaroo Island. Some of these huge clefts are larger than the Grand Canyon in the U.S.A. They wind their way from the outer continental shelf to oceanic depths of approximately 4,600m. They may be important as a valuable source of upwelling water which contributes to the nutrients of the food chain (Von der Borch 1979). The sediments of the canyon walls could contain a record of the major geological changes that occurred during the evolution of the South Australian continental margin. GLORIA sidescan sonar images reveal steep, rugged topography that would probably contain some unique, little known ecosystems (Von der Borch, pers. comm.). Along a rocky section of coast 100 metres north of the Ravine des Casoars, the back part of a Holocene dune containing multiple soil horizons has been preserved at the entrance to a sea cave. The dune provides evidence that during part of the Holocene period the now rocky coast was fronted by a beach/dune system, and as such illustrates the dynamic nature of coasts and the dramatic changes since the Holocene period. The site is significant for both geomorphological research and teaching. Cape Hart Conservation Park (see above). Geological Monuments • − West Bay: Pleistocene aeolianite unconformably overlying Early Cambrian metasediments within Flinders Chase National Park. 300m of coastline with teaching and aesthetic value. • − Cape du Couedic: coastal geomorphology, including Admiral Arch - a major tourist attraction within Flinders Chase National Park. 300m of coastline with teaching, recreation and aesthetic value. • − Remarkable Rocks: spectacular sculptured granite landforms at Flinders Chase National Park. A major tourist attraction. • − Point Ellen, Vivonne Bay: Early Cambrian migmatites and schists overlain by Pliocene shell bed. Spectacular convolute folding in the migmatites and cross cutting pegmatite. 1km of coastline with teaching, scientific and aesthetic value. • − Cape Willoughby Granite Contact: Late Cambrian granite and metasediments of the Kanmantoo Group (Middleton Sandstone). 600m of coastline with teaching, scientific and aesthetic value. 2 OTHER VALUES 2.1 Commercial Fisheries Major single species fisheries in this biounit include the Southern Rock Lobster and Abalone. The biounit is one of the major areas for commercial harvesting of Blacklip Abalone in South Australia. Southern Rock Lobster The southern coast of Kangaroo Island consists principally of 3 fishing zones: Fishing Zone 39 (see Cassini Biounit), Fishing Zone 48 (south western coast) and Fishing Zone 49 (southern coast). In 1995/96 and 1996/97 a total of 37 and 35 licensed operators fished along the south coast of Kangaroo Island (ie. Fishing Zone 48 and 49), catching approximately 128 941 and 118 486 kg of lobsters, respectively (or 2.52% and 2.32% of the total catch for Southern Rock Lobster in South Australian waters). However, the catch is significantly greater (almost twice) in the southern sector (ie. Fishing Zone 49). Approximately 10 of the 24 boats based at Kangaroo Island use Vivonne Bay as their port of landing for Southern Rock Lobster. Abalone Both Blacklip Abalone and Greenlip Abalone are presently commercially harvested within the Gantheaume Biounit. The region, particularly near Cape Gantheaume, represents one of the major areas for the harvesting of Blacklip Abalone in South Australia. In 1994/95 and 1995/96 a total of 8,046 and 11,943 kg of Greenlip was harvested within this region (ie. MapCode 26A-B, 27A-B, 28A-B, 29A-D, 30A-C, West Bay to Charlies Gulch, Destres Bay region), and represented 5.6% and 8.4% of the total Greenlip Central Zone catch Page 223 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT (or 2.14% and 3.19% of the total catch for Greenlip in South Australian waters). In 1994/95 and 1995/96 a total of 33,168 and 32058 kg of Blacklip was harvested within this region, and represented 83.8% and 76.0% of the total Blacklip Central Zone catch (or 6.71% and 6.92% of the total catch for Blacklip in South Australian waters). Hanson Bay Policy Area − Inner Hanson Bay Zone (3,000 ha of coastal waters, within 1km of the coast, from Sanderson Bay to Cape Kersaint, excluding waters adjacent to Cape Bouger Wilderness Area) – zoned for limited coastal aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development in this zone, excluding intertidal oyster culture. − Outer Hanson Bay Zone (3,000 ha of offshore waters from Sanderson Bay to Cape Kersaint) – zoned for R&D open water aquaculture development. Licenses will be considered for a total of 12ha of R&D aquaculture development in this zone. Marine Scalefish Fisheries The southern coast of Kangaroo Island consists principally of 3 fishing zones: Fishing Zone 39 (see Cassini Biounit), Fishing Zone 48 (south western coast) and Fishing Zone 49 (southern coast). During 1995/96 and 1996/97, a total of 42 and 44 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species along the south coast of Kangaroo Island (ie. Fishing Zones 48 and 49), respectively. License holders expended approximately 1620 and 1230 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zones 48 and 49) represented a total of 269,658 kg in 1995/96 and 168,256 kg in 1996/97(or 2.59% and 1.66% of the total catch for the marine scalefish fishery in South Australian waters). Marine scalefish fisheries are not large in this area, and this is mainly due to the rugged nature of the southern coast. There is one Salmon purse seine netter in D'Estrees Bay who nets approximately 400 tonnes/year, although this includes figures from the Eyre Peninsula coast. Deep Sea fishing for Trevalla occurs on the edge of the continental shelf. Commonwealth licence holders in this area use dropline and also shark netting. 2.2 Vivonne Bay Policy Area − Inner Vivonne Bay Zone (840 ha of coastal waters within bay, excluding waters adjacent to Vivonne Bay Conservation Park, Seal Bay Conservation Park and Cape Gantheaume Wilderness Protection Area) – zoned for limited coastal aquaculture. Licenses will be considered for a total of 40ha of aquaculture development in this zone, excluding intertidal oyster culture. − Licenses will not be considered for remaining waters of Vivonne Bay. Cape Gantheaume Policy Area − Inner Cape Gantheaume Zone (5,120 ha of coastal waters, within 1 km of coast, adjacent Cape Gantheaume Wilderness Protection Area to Destres Bay, Point Reynolds, excluding all waters south of southern Destres Bay) – zoned for limited coastal aquaculture development. Licenses will be considered for a total of 40ha of aquaculture development in this zone, excluding intertidal intertidal oyster culture. − Outer Cape Gantheaume Zone (22,280 ha of offshore waters, adjacent Cape Gantheaume Wilderness Protection Area to Destres Bay, Point Reynolds, excluding all waters south of southern Destres Bay) – zoned for R&D open water aquaculture development. Licenses will be considered for a total of 12ha of R&D aquaculture development in this zone. Aquaculture None. The Kangaroo Island Aquaculture Management Plan (Gilliland 1996) proposes limited aquaculture development in this region: Flinders Chase Policy Area − Flinders Chase Policy Area (37,940 ha of waters adjacent to the Ravine Des Casoars Wilderness Protection Area and Flinders Chase National Park) – zoned to protect conservation areas. Licenses will not be considered for aquaculture development in this zone. Page 224 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT Cape Hart Policy Area − − − Inner Cape Hart Zone (4,660 ha of coastal waters, within 1 km of coast, from Point Tinline to Cape Willoughby, excluding Pennington Bay, Mouth Flat Beach and waters adjacent to Cape Hart Conservation Park) – zoned for limited coastal aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development in this zone, excluding intertidal intertidal oyster culture. Outer Cape Hart Zone (22,280 ha of offshore waters, from Point Tinline to Cape Willoughby) – zoned for R&D open water aquaculture development. Licenses will be considered for a total of 12ha of R&D aquaculture development in this zone. Cape Hart Aquaculture Zone (1,000 ha of offshore waters, west of Pennington Bay) – zoned for open water aquaculture development. Licenses will be considered for a total of 200ha of aquaculture development in this zone. Penneshaw Policy Area − − Penneshaw Aquaculture Zone (570 ha of coastal waters, within 1 km of coast, in the west of Cuttlefish Bay and Snapper Point) – zoned for open water aquaculture development. Licenses will be considered for a total of 200ha of aquaculture development in this zone, excluding intertidal aquaculture development . Licenses will not be considered for remaining waters of the Penneshaw Policy Area (19,080 ha, from Cape Willoughby, west to Kangaroo Head). 2.3 Recreation and Tourism − Tourism − Pennington Bay: scenic area, historic area. − D'Estrees Bay and Flour Cask Bay: historic area, fishing. − Cape Gantheaume National Park: scenic area, fishing, diving, wilderness area. − Seal Bay: Australian Sea Lions, scenic area. This is one of South Australia’s major tourist destinations for both national and international tourists. − Vivonne Bay: scenic area, jetty fishing, lighthouse. − Kelly Hill conservation park and Flinders Chase National Park: camping. − 2.4 Pennington Bay: boat fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, Snook, Garfish, Sweep, Toothbrush Leatherjacket, Tommy Rough, Trevally and Silver Drummer. wilderness, scenic area, Cape Borda: scenic area, historic area. Scientific Research and Education − Pennington Bay and surrounding coastal areas have been regular research sites since the early 1940's for marine algal collections and intertidal studies (see Womersley 1948, 1950, Womersley & Edmonds 1958, 1979). − The University of Adelaide has a field research station in Flinders Chase National Park. − SANPWS monitoring of Australian Sea Lion and New Zealand Fur Seal populations. Fishing − Vivonne Bay: boat and jetty fishing. Major species: Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, King George Whiting, Snook, Garfish, Sweep, Toothbrush Leatherjacket, Tommy Rough, Trevally, Silver Drummer and Southern Calamari. Page 225 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT 2.5 Adjacent Land Use National and Conservation Parks − Cape Hart Conservation Park (1,030 ha) (SANPWS 1987). − Seal Bay Conservation Park (1,911ha), Cape Gantheaume Conservation Park (4,220 ha), Cape Gantheaume Wilderness Protection Area (20,100 ha). − Vivonne Bay Conservation Park (1,481 ha) (SANPWS 1987). − Flinders Chase National Park (32,600 ha), Ravine des Casoars Wilderness Protection Area (41,320 ha). − Kelly Hill Conservation Park (2,180 ha), Cape Bouguer Wilderness Protection Area (5,530 ha). Agriculture/Industry Shipwrecks − The west coast of Kangaroo Island is an area of significant historical and cultural value, due primarily to the number and density of shipwrecks and the associated large loss of life (B. Jefferies, pers.comm.). The wrecks in this area include the `Loch Sloy', `Loch Vennachar', `Montebello', `Mars', and the `Emily Smith'. This region has considerable potential for a maritime heritage trail, similar to Wardang Island. − `Loch Vennachar' was one of the finest and fastest three-masted iron ships built at Glasgow in 1875. It disappeared in 1905 in the vicinity of the Neptune Islands. A decomposed body was later found in West Bay of Kangaroo Island. The ship remains were found in 1976, 1 km north of West Bay. The remains are relatively untouched by salvage operations which make them of significant archaeological value. − `Montebello' was a three-masted iron barque, built in France in 1900. The vessel was under charter to the South Australian Farmers Union when it was wrecked off the south coast of Kangaroo Island while sailing from Hobart to Port Pirie. A storm forced the ship onto the rocks on 18 November 1906 near Stun'Sail Boom River. The `Montebello' was quickly broken up by the storm and many of the remains were scattered on the sea bed. All persons survived. This is a spectacular dive but access can be dangerous due to the Southern Ocean swell. − `Osmani’ was lost in 1853, off Point Tinline, Destres Bay and is protected under Commonwealth legislation. 3 CURRENT CONSERVATION STATUS OF THE GANTHEAUME BIOUNIT Those areas not designated in conservation and national parks are mainly agricultural. Urban Centres − Vivonne (population <250). 2.6 Features Significant Cultural or Historical Aboriginal − Not known. European − There is a whaling station located in between the Harriet River mouth and Point Ellen, Vivonne Bay/Flour Cask Bay. It operated in the early 1840's and the area was later used as a landing site in the expanding pastoralism years in the 1880's. It is of State Heritage significance. − Marine Reserves Seal Beach Aquatic Reserve (1,140 ha) − Marine Parks None − Marine Sanctuaries Seal Beach Aquatic Reserve (as above) Page 226 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT − Kangaroo Island Rivers (Chapmans, Harriet, Eleanor, Western and Middle Rivers and all waters within a 50 metre radius of the mouths of those rivers). 4 AREAS OF HIGH CONSERVATION VALUE IN THE GANTHEAUME BIOUNIT Hooded Plover, Osprey, White-bellied Sea Eagle, Eastern Reef Egret, protected waterbirds – 10 species), economic (fisheries-Southern Rock Lobster, Abalone), social (recreationKelly Hill Conservation Park), national (Wetlands of National Importance–Grassdale Lagoons and South West River, Register of the National Estate–Kelly Hill Conservation Park), practicality (insulation, accessibility, compatibility-adjacent to Cape Bouguer Wilderness Protection Area, Kelly Hill Conservation Park). Flinders – Ravine des Casoars Cape Kersaint – Vivonne Bay Netting Closures − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, aesthetic values, cultural values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (geological monumentWest Bay, Cape du Couedic, Remarkable Rocks), ecological (importance for Southern Rock Lobster, Abalone, breeding sites for NZ Fur Seal –Cape du Couedic, North Casuarina, haul out sites for Australian Sea Lions–Cape du Couedic, North and South Casuarina, West Bay Island, high diversity of marine flora and fauna, reefs, estuaries – North West, Breakneck, Sand, Rocky River, Stun'sail Boom River, threatened waterfowl and seabirds– Hooded Plover, White-bellied Sea Eagle, Redcapped Plover, protected waterbirds – 6 species), economic (fisheries-Southern Rock Lobster, Abalone), social (recreation-Flinders national Park, heritage–Cape Borda, shipwrecks-`Loch Sloy', `Loch Vennachar', `Montebello', `Mars', `Emily Smith', `Portland Maru'), scientific (Seal Bay, University of Adelaide field research station), national (Wetlands of National Importance–Flinders Chase National Park), practicality (insulation, accessibility, compatibility-adjacent to Ravine des Casoars Wilderness Protection Area, Flinders Chase National Park). Cape Bouguer – Kelly Hill − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, aesthetic values, cultural values (IUCN Category IB). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (geological monumentRemarkable Rocks), ecological (importance for Southern Rock Lobster, Abalone, haul out sites for NZ Fur Seals and Australian Sea Lions–Cape Bouguer, high diversity of marine flora and fauna, reefs, estuaries–South West River, threatened waterfowl and seabirds– − Prime IUCN Conservation Values: rare and endangered species/habitats, research/education, biodiversity, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (geological monument-Point Ellen), ecological (importance for Southern Rock Lobster, Abalone, breeding sites for Australian Sea Lions–Seal Bay, haul out sites for NZ Fur Seals–Seal Beach, high diversity of marine flora and fauna, reefs, estuaries– Eleanor River, Harriet River, threatened waterfowl and seabirds–Hooded Plover, Whitebellied Sea Eagle), economic (tourism – Seal Bay, fisheries-Southern Rock Lobster, Abalone), social (recreation-Vivonne Bay and Seal Bay Conservation Parks), national (Wetlands of National Importance, Register of the National Estate–Vivonne Bay Conservation Park, Seal Bay), practicality (insulation, accessibility, compatibilityadjacent to Vivonne Bay Conservation, Seal Bay Conservation Park and Aquatic Reserve). Cape Gantheaume − Prime IUCN Conservation Values: rare and endangered species/habitats, biodiversity, research, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (geological monument-Remarkable Rocks), ecological (importance for Southern Rock Lobster, Abalone, significant breeding sites for NZ Fur Seals–Cape Gantheaume, breeding sites for Australian Sea Lions–Cape Gantheaume, high diversity of marine flora and fauna, reefs, estuaries, threatened waterfowl and seabirds– Hooded Plover, White-bellied Sea Eagle), economic (fisheries-Southern Rock Lobster, Abalone), social (recreation-Cape Gantheaume Conservation Park), national (Register of the National Estate–Cape Gantheaume Conservation Park), practicality (insulation, accessibility, compatibilityPage 227 KANGAROO ISLAND COAST – GANTHEAUME BIOUNIT adjacent to Gantheaume Protection Area, Cape Conservation Park). Wilderness Gantheaume D’Estres Bay − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, cultural, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (largest seagrass meadows on south coast of Kangaroo Island), ecological (extensive seagrass meadows, estuaries–Willson River, threatened waterbirds breeding sites, migratory waders and seabirds – Hooded Plover, Osprey, Fairy Tern, Pied and Sooty Oystercatcher, Caspian Tern, Red-capped Plover), economic (fisheries-Southern Rock Lobster, Abalone), social (recreation-Cape Gantheaume Conservation Park, Flour Cask Bay-Whaling Station, shipwrecks-`Osmani'), scientific (Pennington Bay-marine studies), national (Wetland of National Importance-D’Estres Bay, Register of the National Estate–Cape Gantheaume Conservation Park), practicality (insulation, accessibility, compatibilityadjacent to Cape Gantheaume Conservation Park). Submarine Canyons & Basement Highs − Prime IUCN Conservation Values: biodiversity, research (IUCN Category IB). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (deepwater canyon habitat-Sprigg and Murray Canyons, basement highs-Sanders and Carter Knoll), ecological (importance for preservation of unknown canyon ecosystems and habitats, reef flora and fauna of basement highs), economic (fisheries-unknown), national (potential for listing on the Register of the National Estate), practicality (insulation from external threats). Cape Hart − Prime IUCN Conservation Values: aesthetic values biodiversity (IUCN Category III). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), ecological (importance for Southern Rock Lobster, Abalone, high diversity of marine reef flora and fauna), economic (fisheries-Southern Rock Lobster, Abalone), social (recreation-Cape Hart Conservation Park, coastal aesthetic values), practicality (insulation, accessibility, compatibility-adjacent to Cape Hart Conservation Park). Page 228 KANGAROO ISLAND COAST – CASSINI BIOUNIT XXVI MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE CASSINI BIOUNIT This biounit extends from Cape Borda to North Cape, and covers an area of 45,760 ha and represents 24% of the Kangaroo Island coastline (111 km). It faces northwards into the Investigator Strait. MARINE BIOGEOGRAPHY 1 3 Major Inshore Habitats OCEANOGRAPHY This area generally experiences moderate wave energies, with coves and beaches being of low to moderate wave energy. 2 GEOLOGY AND GEOMORPHOLOGY 51 BIOLOGY − Major intertidal habitats in the region include mostly rocky cliffs and shores, estuaries and some sandy beaches. − Of the total inshore subtidal habitats mapped in the biounit (15,868 ha), sandy bottoms comprise 12,943 ha (81.6%), reefs comprise 2 263 ha (14.3%), and seagrass meadows comprise 662 ha (4.2%). COASTAL The Cassini Biounit is dominated by moderate to high sea cliffs usually fronted by shore platforms. Shingle and boulder beaches occur in several locations and are associated with most sand beaches (eg. Dashwood, Smith and, to a lesser extent, Boxing Bays). All beaches are composed of quartz carbonate sands, and are usually fronted by transverse bar and rip surf zones. The beaches are susceptible to winter flooding of creeks across the foreshore and storm wave erosion and overwash which in turn leads to scarping of the parallel foredunes. Emu Bay is bounded by fossil rich Cambrian shales backed by 20 to 50 m high scarped Pleistocene dune calcarenite. The 5 km long low energy beach is prone to storm wave erosion and overwash. The foredune is semi-stable, but dune transgression is prevented by the backing dune calcarenite. Boxing Bay is 2 km in length and similar to Emu Bay. However, a deficiency of the fine quartzcarbonate sand (40% carbonate) plus the occurrence of conglomerate boulders and extensive intertidal calcarenite provide a significant contrast to Emu Bay. Major Benthic Communities • Macroalgal − The rocky shores and reefs of the north west coast of Kangaroo Island, west of North Cape, generally experience moderate wave exposure but strong swell and tidal currents (through Investigator Strait). On these exposed shores, headlands and reefs (eg. Cape Borda, Cape Torrens) are dominated by large, robust, brown algae (ie. Scytothalia dorycarpa, Carpoglossum confluens, Ecklonia radiata, Acrocarpia paniculata, Seirococcus axillaris, Cystophora platylobium), with an understorey of red algae (ie. Plocamium, Callophyllis, Phacelocarpus), green algae (Caulerpa flexilis, C.longfolia) and coralline algae (eg. Haliptilon, Metagoniolithon). In moderate to sheltered areas (eg. Western River Cove, Stokes Bay, Emu Bay), reef areas tend to be dominated by Seirococcus axillaris, with Ecklonia radiata, Scytothalia, Melanthalia and species of Cystophora (C.moniliformis, C.retorta, S.siliquosa, C.expansa) as subdominants, and understorey species of red algae (Plocamium, Phacelocarpus, Sonderopelta, Cladurus elatus) and species of Dictyotales (Zonaria, Dictyota). 51 From Kangaroo Island Coast Protection District Study Report (Edwards 1987). Page 229 KANGAROO ISLAND COAST – CASSINI BIOUNIT • Seagrasses − Seagrass meadows are sparse in this region and are restricted to the sheltered embayments (Emu Bay, Stokes Bay, Western River Cove) and in shallow offshore waters. Sandy sediments are commonly colonised by species of Posidonia (P.sinuosa, P.angustifolia), in shallow water and Heterozostera tasmanica, Amphibolis antarctica and Halophila australis, which tend to extend to deeper waters (ie. 15m). Other species also colonise sandy sediments, particularly species of Caulerpa (eg. C.trifaria). • − Cape Torrens Conservation Park Is a representative example of the spectacular coastal cliffs of the north coast. Some 57 species of birds have been recorded in the park. The cliff top coastal vegetation consists of Acacia paradoxa with some Olearia and Goodenia spp. The park is on the Register of the National Estate, and was abolished in 1993 and proclaimed as the Cape Torrens Protection Wilderness Protection Area under the Wilderness Protection Act 1992. • − De Mole River Estuary: has a surrounding stand of Allocasuarina verticillata, which is an important habitat for the rare and threatened Glossy Black Cockatoo. The De Mole River estuary is also considered to be an area of great scenic beauty (E. Oks 1986). • − Middle River: The mouth of Middle River (at Snelling Beach) has the densest and largest area of coverage of Sea Rocket (Cackile maritima) found near any of the river mouths on Kangaroo Island or the mainland. Wading birds use the mudflats and lagoon areas for feeding and breeding. Rivers and Estuaries − Western River estuary. − De Mole River estuary. − Middle River estuary. − There are some twenty other named creeks and rivers that enter the sea along this section of the coast. MARINE CONSERVATION VALUES 1 1.1 • − SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES 1.2 AND − Coastal areas that are considered to be particularly spectacular include the coast from Cape Borda to Cape Torrens. This section of coast has the highest coastal cliffs on Kangaroo Island (263 m). Snelling Beach is also a popular viewing area. − Cape Torrens Conservation Park (see above). − Western River Conservation Park (see above). Biological Western River Conservation Park The Western River estuary and outstanding coastal cliffs have been conserved in the Western River Conservation Park (2,364ha). A total of 78 species of birds have been recorded in the park. The estuary and conservation park is also considered to be an area of outstanding beauty. The park is on the Register of the National Estate. Its natural and wilderness values are also protected as the Western River Wilderness Protection Area under the Wilderness Protection Act 1992. Western River Cove is a very popular diving location with local dive operators and is recognised for a wide range of marine habitats and species (over 270 species), and abundant fish life (including Leafy Sea Dragons, Telma Butterfly fish, Old Wives, Blue Devils, Morwong, Harlequins and Blue Groper). Physical Geological Monuments • − Smith Bay: Striated glacial pavements of Permian age developed on Early Cambrian strata. A raised beach along 1k m of coastline. The site has high teaching value. • − Stokes Bay: Geomorphological features derived form Pleistocene aeolianite unconformably overlying Early Cambrian felspathic sandstone. 300 m of coastline with teaching and research value. Page 230 KANGAROO ISLAND COAST – CASSINI BIOUNIT • − Harveys Return: Spectacular slumping and folding in metasediments of the Kanmantoo Group. Distinctive regular layering of black biotiterich and grey quartz-rich bands. 400m of cliffs and shoreline around a rocky cove with teaching, research, scientific aesthetic and recreational value. Fishing also occurs in Fishing Zone 39, along the north western coast of the island, and also the offshore islands in this region (Gambier Islands, Neptune Islands, and Thistle Island). In 1995/96 and 1996/97, a total of 21 and 31 licensed operators fished in the area (ie. Fishing Zone 39), catching a total of 66,188 and 86,753 kg, respectively (or 0.64% and 0.86% of the total catch for the marine scalefish fishery in South Australian waters). • − Emu Bay - Cape D'Estaing: Type section of Emu Bay Shale and part of an outstanding sequence of Early Cambrian rocks. Two sections of coast 300 m and 1.5 km long with teaching and scientific value. Marine scalefish fishing in this region includes 1 Salmon purse seining operation along the north coast of the island, and in the bays. Some line fishing also occurs along the north coast. 2.2 2 2.1 OTHER VALUES Commercial Fisheries Major single species fisheries in this biounit are the Southern Rock Lobster, and Abalone. This section of the coast of Kangaroo Island is frequented by license holders from the mainland as well as those on the island itself. − Cape Cassini Policy Area − Inner Cape Cassini Zone (inshore waters from Point Marsden, west to Cape Dutton, excluding Stokes Bay, Emu Bay and Boxing Bay) – zoned to provide for limited coastal aquaculture development. Licenses will be considered for a maximum of 60ha of aquaculture development in this zone, excluding intertidal oyster culture. − Outer Cape Cassini Zone (21,380 ha of offshore waters from Point Marsden, west to Cape Dutton) – zoned for R&D open water aquaculture development. Licenses will be issues for a total of 12 ha of R&D aquaculture development in this zone. − Cape Cassini Aquaculture Zone (1 000 ha of offshore waters between Cape Cassini and Emu Bay) – zoned for open water aquaculture development. Licenses will be considered for a total of 200ha of aquaculture development in this zone. Marine Scalefish Fisheries During 1995/96 and 1996/97, 28 and 31 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species along the north coast of Kangaroo Island (ie. Fishing Zone 41), respectively. License holders expended approximately 823 and 799 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 41) represented 182,476 kg in 1995/96 and 60,654 kg in 1996/97(or 1.76% and 0.60% of the total catch for the marine scalefish fishery in South Australian waters). None. The Kangaroo Island Aquaculture Management Plan (Gilliland 1996) proposes the following aquaculture development in this region: Southern Rock Lobster In 1995/96 and 1996/97 a total of 8 and 4 licensed operators fished along the north coast of Kangaroo Island (ie. Fishing Zone 41). However, the north western coast of the island, and the offshore islands in this region (Gambier Islands, Neptune Islands, and Thistle Island), represent a major region for lobster fishing in South Australia. In 1995/96 and 1996/97, a total of 51 and 47 licensed operators fished in the area (ie. Fishing Zone 39), catching approximately 108,867 and 136,826 kg of lobsters, respectively (or 2.13% and 2.68% of the total catch for Southern Rock Lobster in South Australian waters). Aquaculture Cape Torrens Policy Area − Inner Cape Torrens Zone (5,310 ha of coastal waters, within 1 km of the coast, from Cape Dutton, west to Ravine Des Casoars, excluding Snelling Beach and waters adjacent to Western River and Cape Torrens Wilderness Protection Areas) – zoned for limited coastal aquaculture development. Licenses will be considered for a total of 60ha of aquaculture development in this zone, excluding intertidal oyster culture. Page 231 KANGAROO ISLAND COAST – CASSINI BIOUNIT − − Outer Cape Torrens Zone (21,340 ha of offshore waters from Cape Dutton, west to Harvey’s Return, Ravine Des Casoars) – zoned for R&D open water aquaculture development. Licenses will be considered for a total of 12ha of R&D aquaculture development in this zone. Cape Torrens Aquaculture Zone (1 000 ha of offshore waters between Snelling Beach and Western River Cove) – zoned for open water aquaculture development. Licenses will be considered for a total of 200 ha of aquaculture development in this zone. − Western River Cove and Stokes Bay: fishing, camping, swimming, surfing, shacks. The eastern part of Stokes Bay has a small beach area that is protected by the offshore reef and is consequently a safe swimming area. − Emu Bay: boating, swimming, fishing, scenic area, diving in underwater caves and around Cape D'Estaing. − Snelling Beach is a relatively safe swimming beach. − Cape Torrens Conservation Park has particularly spectacular diving and coastal scenery. − Cape Cassini: diving, scenic area. − SCUBA diving: there are many popular diving sites on the north coast of Kangaroo Island, which offer accessible, all-weather diving. The whole of the north coast of Kangaroo Island, including Western River Cove, contain many popular and recognised dive spots and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Flinders Chase Policy Area − Flinders Chase Policy Area (waters adjacent to the Ravine Des Casoars Wilderness Protection Area and Flinders Chase National Park) – zoned to protect conservation areas. Licenses will not be considered for aquaculture development in this zone. 2.3 Recreation and Tourism Fishing − − − − Stokes Bay: boat and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, King George Whiting, Snapper, Snook, Garfish, Sweep, Toothbrush Leatherjacket, Southern Rock Lobster, Tommy Rough, Trevally, Silver Drummer and Calamari. Western Cove is a particularly popular diving location with local dive operators (eg. Kangaroo Island Diving Safaris) and is recognised for a wide range of marine habitats and species (over 270 species), and abundant fish life (including Leafy Sea Dragons, Telma Butterfly fish, Old Wives, Blue Devils, Morwong, Harlequins and large Blue Groper). Sea lions and seals also often frequent the sheltered inlets and rock pools on the north coast of the island. Emu Bay: jetty, boat and rock fishing. Major species: Sand Flathead, Yelloweye Mullet, Australian Salmon, King George Whiting, Snapper, Snook, Garfish, Sweep, Toothbrush Leatherjacket, Tommy Rough, Trevally, Silver Drummer and Calamari. 2.4 Tourism − Scott Cove and Harveys Return are both within Flinders Chase National Park and are popular coastal destinations for visitors enroute to the Cape Borda lighthouse - scenic and historic area. 2.5 Scientific Research and Education Not known. Adjacent Land Use National and Conservation Parks − Small section of Ravine des Casoars Wilderness Protection Area, by Cape Borda. − Cape Torrens Wilderness Protection Area (751 ha) (SANPWS 1987). Snug Cove: boating, fishing, diving. Page 232 KANGAROO ISLAND COAST – CASSINI BIOUNIT − − Western River Conservation Park (167 ha), Western River Wilderness Protection Area (2,373 ha) (SANPWS 1987). − `Fairfield’ , lost in 1874 off Cape Cassini. − `Portland Maru’, a steel steamship, measuring 385 feet, built in Japan in 1919. It was wrecked off Cape Torrens in 1935, and has been recommended for protection under Commonwealth legislation. The wreck is a very popular dive site and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). 3 CURRENT CONSERVATION STATUS OF THE CASSINI BIOUNIT Lathami Conservation Park (1,190 ha). Agriculture/Industry Most of the adjacent land in this biounit is used for agricultural purposes. Urban Centres There are no large urban centres along this section of the coast. However, holiday shacks and private developments have occurred opposite most of the pocket beaches. Public access and facilities occur at the major beaches of Western River Cove, Snelling Beach and Stokes Bay. 2.6 Features Significant Cultural or Historical Aboriginal − Sites of cultural significance have been identified along the Western River. − Marine Reserves None − Marine Parks None − Marine Sanctuaries None Netting Closures − Kangaroo Island Rivers (Chapmans, Harriet, Eleanor, Western and Middle Rivers and all waters within a 50 metre radius of the mouths of those rivers). 4 AREAS OF HIGH CONSERVATION VALUE IN THE CASSINI BIOUNIT European − − Many of the geographical names along this section of Kangaroo Island were named by the French explorer, Baudin, as detailed in Cockburn (1984). Harvey's Return was discovered by two men, Whalley and Harvey in 1834, when searching for a place to land near Cape Borda (Cockburn 1984). In 1858 the Cape Borda Lighthouse was constructed. Shipwrecks There are 3 wrecks that are located in this area, many of which are of significant historical value and are also protected under Commonwealth legislation: − `Fides' was a three masted wooden barque built at Christianastadt, Finland in 1857. It was wrecked Snug Cove whilst on its journey to Port Adelaide from London in 1860. The wreck is situated against the cliffs in about 10 metres of water on a gravel seabed. Vast numbers of beer keg taps have been recovered from the site as well as bottles, fruit preserved in bottles, bullets and an ingot of metal. Only fragments of glass and the occasional tap can now be found on the site. There is an interpretive plaque near the wrecksite. Cape Torrens – Harry’s Return − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, cultural, aesthetic values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values, coastal cliffs), biogeographic (representative habitats, geological monument–Harveys Return), ecological (rare and threatened species– Glossy Black Cockatoo, haul out sites for NZ Fur Seals and Australian Sea Lions, habitats for marine flora and fauna, reefs, estuaries– De Mole River, 57 bird species), economic (fisheries-Southern Rock Lobster, marine scalefish fisheries), social (diving and recreation, Cape Torrens Wilderness Protection Area, shipwrecks-`Portland Maru' at Cape Torrens), scientific (Harveys Return), national (Register of the National Estate–Cape Torrens Wilderness Protection Area), practicality (insulation, accessibility, compatibility-adjacent to Cape Torrens Wilderness Protection Area). Page 233 KANGAROO ISLAND COAST – CASSINI BIOUNIT Smith Bay Western River Cove – Snug Cove − − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, cultural, aesthetic values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values, coastal cliffs), biogeographic (representative habitats), ecological (haul out sites for NZ Fur Seals and Australian Sea Lions, habitats for marine flora and fauna, reefs, estuaries– Western River, 78 bird species), economic (commercial dive tourism, fisheries-Southern Rock Lobster, marine scalefish fisheries), social (diving-Western River Cove, recreationWestern River Cove, Snug Cove, aboriginal heritage–Western River region, shipwrecks`Fides’ at Snug Cove, Western River'), national (Register of the National Estate– Western River Wilderness Protection Area), practicality (insulation, accessibility, compatibility-adjacent to Western River Wilderness Protection Area and Conservation Park). Stokes Bay − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, cultural, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change, wilderness values), biogeographic (geological monument–Stokes Bay, representative habitats), ecological (haul out sites for NZ Fur Seals and Australian Sea Lions, habitats for marine flora and fauna, reefs), economic (commercial dive tourism, fisheries-Southern Rock Lobster, marine scalefish fisheries), social (diving-Stokes Bay, recreation-fishing, shipwrecks-Stokes Bay'), national (potential for listing on the Register of the National Estate–Stokes Bay), practicality (accessibility, compatibilityadjacent to Lathami Conservation Park). Prime IUCN Conservation Values: social values, biodiversity, rare and endangered species/habitats, cultural (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (representative habitats–large reef coastal reef platform, geological monument–Smith Bay), ecological (haul out sites for NZ Fur Seals and Australian Sea Lions, habitats for marine flora and fauna, reefs), economic (commercial dive tourism, fisheries-marine scalefish fisheries), social (diving, recreation-Emu Bay, heritage– shipwrecks-`Fairfield’ at Cape Cassini), national (potential for listing on the Register of the National Estate), practicality (insulation). Emu Bay and Boxing Bay − Prime IUCN Conservation Values: biodiversity, rare and endangered species/habitats, cultural, social values (IUCN Category II). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (representative habitats–largest seagrass meadows on north east coast, geological monument – Emu Bay to Cape D’Estaing), ecological (haul out sites for NZ Fur Seals and Australian Sea Lions, habitats for marine flora and fauna, reefs, seagrass meadows), economic (commercial dive tourism, fisheries-marine scalefish fisheries), social (diving-Cape D’Estaing, recreation-Emu Bay, heritage – shipwrecksEmu Bay), national (potential for listing on the Register of the National Estate), practicality (accessibility). Page 234 SOUTH-EAST COAST REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE SOUTH EAST COAST MARINE BIOGEOGRAPHY 1. 2. 3. 4. 5. The South East Coast Oceanography Climate Coastal Geomorphology and Landforms Biology MARINE CONSERVATION VALUES 1. 2. 3. Significant Biological and Physical Features Significant Cultural and Historical Features Current Conservation Status of the South East Coast BIOUNITS 1. 2. 3. 4. Coorong Canunda Nene Piccaninnie Page 235 SOUTH-EAST COAST REGION MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE SOUTH EAST COAST MARINE BIOGEOGRAPHY 1 THE SOUTH EAST COAST The South East coast extends from the Murray Mouth eastwards, to at least the Victorian border and represents a coastal distance of approximately 390 kilometres. The coastal waters of this region represent some of the most diverse and productive waters of South Australia. As such, this region contains one of the highest centres of algal or seaweed diversity in the world. This diversity is in part due to the overlap of two major biogeographical regions. Unlike rest of the South Australia, the fauna and flora east of Robe is akin to the biota of the cooler waters of Victoria and Tasmania, while west of Robe the biota is typical of the warmer waters of western South Australia and Western Australia. The South East coast is also a region of considerable coastal productivity, providing some of South Australia's most productive fisheries, in particular the Southern Rock Lobster and Abalone fisheries. This productivity is primarily a result of the unique, nutrient-rich coastal upwellings which occur in this region. These nutrient-rich upwellings represent the most significant upwellings to be found along the whole of the Southern Australian coastline. The South East coast is also characterised by spectacular coastal landforms such as the Coorong lagoons, which not only support extensive populations of migratory waterbirds, but also preserve important records of our Pleistocene history. For the most part, the coast is oriented in a south and southwesterly direction into the Southern Ocean and experiences some of the highest wave energies (eg. Canunda region) in South Australia.. 1.1 Coast Biogeography of the South East Along the southern coast of Australia, marine biogeographers recognise a major biogeographic region, known as the Flindersian Province, which extends from south-west Western Australia to southern New South Wales (Bermagui) and includes the waters of Victoria and Tasmania. Within this broad region, the coastal waters of the south east coast of Australia (east of Robe) are recognised as cold temperate, in contrast to the warm to cool temperate waters of the Great Australian Bight (west of Robe) (Womersely & Edmonds 1958). At the boundary of this major biogeographical region, the cold temperate marine fauna and flora of the lower South East coast is unlike any other coastal region of South Australia. This distinct biogeographical region (known as the cold-water Maugean Subprovince) is characterised by slightly lower temperatures and different species assemblages, compared to that found west of Robe. The Maugean Subprovince is characterised by the following biological features: − a virtual absence of barnacles in the upper and mid eulittoral zones, which are populated mainly by molluscs (especially chitons); − prominence of the red alga Porphyra columbiana in the mid eulittoral zone during winter; − presence of the giant, cold water, brown algae or kelps, such as Durvillaea potatorum (Bull Kelp) and Macrocystis angustifolia; and the − presence of other cold water algae such as Myriogloia sciuris, Eudesme harveyana, Codium fragile, Grateloupia sp. and Pleonosporium comatum. Within the Maugean Subprovince, the South East coastal and marine ecosystems encompass 2 welldefined biogeographical regions known as the Coorong Bioregion and the Otway Bioregion. The Coorong coast is encompassed within the Coorong Bioregion, which extends from Port Elliot to Cape Jaffa (IMCRA 1997). However, the lower South East region, from Cape Jaffa to the Victorian border, falls within another marine biogeographic known as the Otway Bioregion, which extends from Cape Jaffa to slightly north of Apollo Bay (Victoria) and King Island (Tasmania) (IMCRA 1997). A complete physical and ecological biogeographic description of the Coorong Bioregion and Otway Bioregion, including marine fauna and flora, has been described by IMCRA (1997). Page 236 SOUTH-EAST COAST REGION Based on coastal geology, wave climate, and coastal orientation, Short and Fotheringham (1986), identified three coastal geomorphological regions (or subprovinces) for the South East coast. 52 1 2 3 Coorong Subprovince (from Middleton, Encounter Bay to Cape Jaffa, 190 km). Robe Range Subprovince (from Cape Jaffa to Cape Banks, 140 km). Port MacDonnell Subprovince (from Cape Banks to the Victorian border, 60 km). These coastal subprovinces correspond to 4 finerscale marine biogeographical regions or biounits: Despite this, surface waters exhibit a seasonal cycle of minimum salinity and maximum temperature (35.2%., 18oC) during summer, and maximum salinity and minimum temperature (35.8%., 14oC) during winter (Lewis 1981). During winter, the water column is well mixed (35.6%.,14oC) with stratification beginning in October. From December, the lower layer exhibits decreased temperatures (11-12oC) and salinity (35.2%) due to the influence of upwellings. Shallow waters and rock pools in calmer areas are subject to a greater range in temperatures (Womersley & Edmonds 1958). 2.3 1. 2. 3. 4. 2 2.1 Coorong Biounit (from Port Elliot to Cape Jaffa,) Canunda Biounit (from Cape Jaffa to Cape Banks) Nene Biounit (from Cape Banks to Cape Northumberland) Piccaninnie Biounit (from Cape Northumberland to Victorian border) OCEANOGRAPHY Wave Climate The whole of the South East coast is subject to high deepwater wave energy attenuated by an offshorenearshore gradient. This results in varying wave energies along the coast. As such, wave energy ranges from very high, at the northern end of Younghusband Peninsula, the Robe Range, and near the Victorian Border, to moderate in Guichen Bay and Rivoli Bay, and to low in Lacepede, Bucks and MacDonnell Bays. Massive beach erosion and foredune scarping is high for most of the South East coast owing to storm surges. A predominant southwest swell also impinges on the coast for most of the year. Tides are generally micro-tidal in range and semidiurnal, with a moderate diurnal inequality. 2.2 Water Temperature and Salinity Ocean surface temperatures along the South East coast are consistently lower than for other coastal regions of South Australia (Womersley & Edmonds 1958). However, annual temperature and salinity fluctuations are complicated, due in part to local upwellings. Currents and Upwellings The considerable coastal productivity of the South East coast is primarily a result of the presence of nutrient-rich upwellings. The upwellings along this region represent the most significant coastal upwellings to be found along the whole of the Southern Australian coastline, and are due, in part, to the meterological conditions of the region. The movement of anticyclonic air streams, from west to east, induce a general easterly baroclinic water transport along the southern coast and within this, numerous anticyclonic and intermittent eddies (Bye 1970). The centres of the anticyclonic air streams are considerably further north in winter than in summer. In the lower South East, this frequently causes a north-westerly wind in winter and a south easterly wind in summer. The latter acts on the thermohaline structure of the water producing a current in the warmer upper layers which moves towards the coast and is then deflected away. As a result, there is upwelling of colder, nutrient-rich, less saline water. Three centres of upwelling have been identified in the South East region: Robe, Southend and Port MacDonnell (Lewis 1981). 2.4 Groundwater Drainage In the lower South East lie two important aquifers below the surface water system. The first is an unconfined aquifer in the Gambier Limestone, and below this, is a confined aquifer in the Dilwyn Formation. Beach springs are found along the coastline east of Port MacDonnell and offshore seepage occurs between Port MacDonnell and the Victorian border and also, in the Robe-Beachport area. Consequently, any pollution of the aquifer is likely to have some impact on the marine environment, depending on the degree of dilution achieved. 53 53 52 From South East Coast Protection District Study Report (UEPG 1982). South East Coast Protection District Study Report (UEPG 1982). Page 237 SOUTH-EAST COAST REGION 3 CLIMATE The South East is characterised by a typical `cool temperate', mesothermal climate, with cool, wet winters and warm, dry summers. Beachport has one of the highest influential rainfall periods (nine months), in the state (Gentili 1972). However, the entire South East coast suffers from a marked lack of moisture due to high evaporation rates. 4 COASTAL GEOMORPHOLOGY LANDFORMS AND There are five major macro-scale landform elements recognised along the South East coast (Short & Hesp 1984): 4.1 Outer Dune Barrier Complexes Younghusband Peninsula and Robe. of Younghusband Peninsula began as a barrier complex formed during a relatively high sea level around 80,000 years B.P. resulting in Pleistocene calcreted basal unit overlaid by Holocene noncemented dunes. Outcrops of this calcreted component can be seen along the Robe range and Beachport (Von der Borch 1976). Robe Range is a barrier complex formed during low sea level periods between 220,000 and 180,000 years B.P, and has been subsequently uplifted and surrounded by high sea levels (Sprigg 1979). It is subject to hind-dune instability due to spatial variations in breaker wave energy, nearshore gradients and beach and foredune instability. The most unstable areas are mid-Younghusband Peninsula and Canunda, with Canunda experiencing the highest breaker wave energy along the southeast coast (Short & Hesp 1984). Moderate breaker wave energy and rip circulation has caused fore-dune erosion and consequential hind dune instability between Nora Creina and Beachport. 4.2 Beach-Ridge Plains of Lacepede, Guichen and Rivoli Bays The Beach-Ridge Plains may be a unique expression of sea level changes during the Holocene, and as such it represents a geologically significant area. More than 7,000 years ago the inter-barrier depression between the Robe and Woakwine Ranges was breached by the sea, causing the Lower River Murray Valley to flood, and the Younghusband Peninsula and the Robe Range to become nearshore islands. Deposition of Holocene sediments caused the inter-barrier depression to become a tidal estuary, with openings in the outer barrier. A subsequent high rate of sediment supply in the Lacepede, Guichen and Rivoli embayment, combined with low to moderate breaker wave energy, resulted in the closure of the estuaries and a prograded coastline backed by plains of low stranded dunes extending from the Woakwine Range to the present shoreline (Short & Hesp 1984). Generally, the foredune complexes and their backing beach-ridge systems are relatively stable. Higher breaker wave energies may contribute to some instability in Guichen Bay. 4.3 Coorong and Robe Range-Woakwine Range Depressions. The Coorong Depression extends from Murray lakes to Cape Jaffa, and contains the Coorong Lagoon, ephemeral pipe clay lakes and swamps. 5,000 years ago, this depression was an estuarine environment. Subsequent infilling of the estuary with the Lacepede Bay beach ridge occurred and together with the closing off of the Southern Coorong to the sea, created the ephemeral saline environments of the Kingston Lake Chain. The Robe Range-Woakwine Depression consists of a corridor of estuarine, clay and shell beds, deposited during the mid-Holocene when the corridor contained an unconfined lagoon, with estuaries at Guichen and Rivoli Bays. Infilling of the estuaries resulted in the corridor formation. 4.4 Stranded Pleistocene Barriers and Relict Coast of the Robe Range Outer Barrier. This landform occurs in three major areas: 1 landward of the Coorong inter-barrier depression: relatively stable and not subject to active coastal processes. 2 as the Woakwine Range stranded barrier complex: relatively stable and not subject to active coastal processes. 3 as outcropping calcrete remnants along the Robe Range: remnants found as rocky headlands, offshore islands, wave-cut platforms and reefs. Page 238 SOUTH-EAST COAST REGION 4.5 Tertiary Limestone Plain of the Lower Southeast. Characterised by low undulating plain, sometimes outcropping at the coast as reefs and rocky headlands, and sometimes capped with Holocene beach and dune deposits. Depressional areas are relatively common and contain swamps and peat deposits. Holocene Beach Dune Systems Offshore reefs along the coast reduce wave energy and interrupt sediment transport, influencing the morphology of the beach dune systems such that relatively low energy, stable shoreline in the lee of the reefs occurs with a tendency to build shingle beach ridges. Shingle beach-ridges are common near Blackfellows Caves, and in Umpherstone, Blanche, Racecourse and Riddoch Bays. Rocky Coast This comprises the Gambier limestone formations which consists of limestone outcrops at the coast producing dominant cliffed headlands, and the low, gently undulating plain developed over the Gambier limestone back from the coastline. Major coastal outcroppings occur at Bucks Bay, Blackfellows caves, Douglas Point and Cape Northumberland. 5 5.1 BIOLOGY General Ecology A diverse range of marine and estuarine habitats are represented along the South East coast. These include: rocky shores, seagrass meadows, sandy beaches and dunes, estuaries and lagoons, sheltered embayments, and subtidal and offshore reefs. No stands of the Grey Mangrove, Avicennia marina are present in this region. The coastal region of the South East coast is typically dominated by extensive offshore, parallel, flat platform aeolianite reef systems which extend offshore from, approximately 350 km to the continental shelf margin in the Coorong and Murray Mouth region (ie. south of Kangaroo Island), to a narrow continental margin, approximately 10 km wide in the coastal areas south of Robe. This reef system generally extends from, the 11 metre depth contour off the Coorong, to approximately 8 metres in the coastal areas south of Robe. In low wave energy areas, these offshore reefs make possible the existence of seagrass beds which also provide food and shelter for numerous organisms, including the Southern Rock Lobster (Jasus edwardsii) (eg. Kingston). The waters of the South East coast, contain some of the highest levels of marine biodiversity and also, productivity in South Australia. East of Robe, nearshore marine habitats are characterised by cold temperate fauna and flora (ie. the Maugean Subprovince of Tasmania, Victoria, south-east South Australia), particularly the presence of the kelps, Macrocystis angustifolia and Durvillea potatorum, which occur west of Cape Jaffa. Despite the productivity and biodiversity of the region, few marine biological studies, particularly subtidal research, have been undertaken in the region. This is largely due to the very exposed and inaccessible nature of the coast. The intertidal assemblages on the rocky coastline of the South East has been relatively well-described by Womersley and Edmonds (1958). Animals dominate the littoral fringe, the upper eulittoral and the mid-eulittoral zones, while plants dominate the lower eulittoral and sublittoral zones. In the littoral fringe blue green alga, lichen and small gastropods may be found, whilst in the eulittoral zone, worms, algae (eg. Hormosira banksii), and various species of gastropod molluscs such as chitons and limpets will be found. In the sublittoral zone the Bull Kelp (Durvillaea potatorum) occurs east of Cape Jaffa, on the outer edges of reefs subject to high wave energy. In the deeper, protected rock pools, other species are common such as algae (eg. Cystophora sp., Sargassum sp.), abalone (eg. Haliotis laevigata) and various ascidians, asteroids, echinoids, anemones, and crustaceans. 5.2 Subtidal Ecology The whole south-east region of South Australia is typified by both, low and high wave energies, depending on the presence/absence of these offshore reefs, which attenuate wave energy. Exposed coastal areas, particularly from Cape Buffon to Cape Banks, are typified by a high swell (2-4m), high wave energy environment, which is strongly erosional in nature and characterised by conditions of strong surge and sand scour. Low wave energies occur in the few coastal embayments of Lacepede, Guichen, Rivoli Bays and Nora Creina, due to attenuation by offshore reefs. The offshore reef system is patchy in areas, and is interspersed with areas of medium to coarse sand (without seagrass). Page 239 SOUTH-EAST COAST REGION Due to the lack of depositional environments, soft bottom habitats (colonised by seagrass communities) are rare along the south-east coast region of South Australia. Seagrass habitats (dominated by Posidonia australis, Amphibolus antarctica and Heterozostera tasmanica are present, but rare, being mainly confined to the sheltered areas of southern Lacepede Bay (where extensive meadows occur), northern Rivoli Bay, Nora Creina, Guichen Bay and the sheltered interreefal areas west of Port MacDonnell. The dune calcarenite bedrock characteristically forms low platform reefs, with abundant crevices and microhabitats for calcareous organisms (particularly coralline algae and bryozoans) and sponges. As on Kangaroo Island, species of Caulerpa (eg. C.obscura, C.cactoides, C.brownii) appear to play a key role in colonising sediments and consolidating sediments on low platform reefs. Kelp forests (dominated by Macrocystis angustifolia), dominate in exposed to moderately areas areas (from Cape Jaffa eastwards), in the 1025 metre depth range - providing significant shelter for inner reefs (ie. via reducing wave energy). Kelp forests are generally absent from the Canunda region (ie. from Cape Buffon to Cape Banks) due to the general absence of reefs and high wave energies. Few detailed subtidal marine biological studies have been conducted along the South East coast. Shepherd (1979) recorded over 180 algal species from Cape Northumberland, and recognised three distinct algal communities, which are probably characteristic of most of the lower South East region: 1 a red algal community at 4-10m comprising plants up to 0.1m high (ie. Chondria, Gelidium glandulaefolium, Hymenena affinis, Laurencia elata, L.filiformis, Melanthalia concinna, M.obtusata and Phacelocarpus complanatus) with only scattered plants of larger brown algae (ie. Acrocarpia paniculata, Ecklonia radiata, Carpoglossum confluens, Perithalia caudata) and patches of Caulerpa flexilis. 2 an Ecklonia radiata/red algal community from 10m to 15-30m, with Ecklonia as the dominant canopy species, with an understorey of red algae (eg. Callophyllis lambertii, Melanthalia obtusata, Nizymenia australis, Phacelocarpus complanatus, P.labillardieri). 3 a deep water (30-38m to 61m), sparse red algal community (ie. Lenormandia marginata, Phacelocarpus complanatus, Pterocladia lucida, Rhodophyllis multipartita and Ptilonia australasica). In shallow waters, down to 13m, major macrofaunal reef species include grazing molluscs, Subninella undulata and Haliotis rubra (Blacklip Abalone), and the Southern Rock Lobster (Jasus edwardsii), which is typically found in crevices or caves, and feeds on the sea urchins, Halopneustes porossima and Amblypneustes sp. The Red Rock Crab and Rough Rock Crab are found occasionally, as well as the stalked ascidian, Pyura australis. At deeper depths (from 13-15m), the molluscs, Aplysia parvula, Anthochiton tricostalis, Choriplax pattisoni and Paricoplax crocina and the isopods, Cilicaea curtispina and Synischia sp, the Weed Crab, Naxia tumida, and the echinoderm, Aporometra wilsoni, are commonly found (Shepherd 1979). 5.3 Fish The coastal and adjacent offshore fish fauna of the South East is significant because of its considerable commercial importance. However, the lesser-known inland fish fauna is also significant in this region because it occupies the most westerly part of Australia's South East Coast Drainage Division. The inland waters in the Coorong range in salinity from fresh through brackish to very saline. They can, therefore, be selectively occupied by marine fishes, as well as species which tolerate intermediate ranges of salinity. At least twenty four marine and freshwater species have been recorded from the inland waters of the Coorong (Glover 1983). Of these, five are known to regularly move between the sea and fresh or brackish estuarine waters to breed. A further four species are essentially marine forms which regularly enter brackish estuarine and fresh inland waters, as well as inland saline waters. Other marine fishes recorded in inland waters include several marine fishes such as Shark and Ray, Flounder, Sea Bream, Trevally, King George Whiting and Australian Salmon/Salmon Trout. Species that live in both the sea and fresh or brackish water at some stage during their life cycle include: − − − − − − Short Headed Lamprey (Mordacia mordax) Wide Mouthed Lamprey (Geotria australis) Short Finned Eel (Anguila australis) Common Galaxias (Galaxias maculatus) Sea Mullet (Mugil cephalus) Yellow Eye Mullet (Aldrichetta forsteri) Page 240 SOUTH-EAST COAST REGION Small Mouthed Hardyhead (Atherinosoma microstoma) Marine Hardyhead (Pranesus ogilbyi) Mulloway (Argyrosomus hololepidotus) Black Bream (Acanthopagrus butcheri) Congolli (Pseudaphritis urvillii) Along rocky shores in the cooler areas, the marine flora is dominated by spectacular forests of kelp (Macrocystis angustifolia) in the deeper waters, and in the upper subtidal, by a zone dominated by the giant, Bull Kelp (Durvillea potatorum). Of particular significance in the lower South East is the Australian Grayling (Prototroctes maraena), which is one of Australia's rarest and most extinction-threatened fishes. This species probably spends part of its life in the sea. In the lower South East it has only been recorded in Ewens Ponds and Picanannie Ponds (Glover 1983, Thurgate 1992). The coastal waters off the South East are among some of the most productive waters along the whole of the southern Australian coastline. This is primarily a result of the presence of nutrient-rich upwellings. As such, this region is significant for a number of commercially important species, including the Southern Rock Lobster, Abalone and the Goolwa Cockle. − − − − − 5.4 Seabirds Bird life is prolific along the South East coast, particularly along the Younghusband Peninsula, due mainly to the estuarine conditions of the Coorong. The Murray Mouth is an area rich in fish and bird species such as the Cape Barren Goose (Cereopsis novaehollandiae), Plovers (Vanellus sp. and Pluvialis sp.) and Dotterels (Charadrius sp.). Rare or endangered bird species that might nest in the sand dunes of the Coorong region include the Rufous Bristlebird (Dasyornis broadbenti), and the Orange-bellied Parrot (Neophema chrysogaster). 5.5 Marine Mammals Cetaceans have also been found washed up on the beach and include notable specimens of a Pigmy Right Whale (Caperea marginata), a Pigmy Sperm Whale (Kogia breviceps), a Sperm Whale (Physeter macrocephalus) and a Minke Whale (Balaenoptera acutorostrata). MARINE CONSERVATION VALUES 1 1.1 Commercially Exploited Species SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND The Coorong The Coorong is a unique coastal landform with a shallow backwater estuary and ephemeral salt lake system that drains gradually into the sea behind a semi-consolidated sand barrier, the Younghusband Peninsula. The Coorong lagoons are an important feeding, breeding, spawning and nursery area for fish as well as supporting one of the largest concentrations of migratory waders in Australia. The ocean beach adjacent to the Coorong National Park and Game Reserve is an important nesting area for the Australian endemic Hooded Plover (Charadrius rubricollis) and some 27 other species of seabirds and waders have been recorded here. The marine biota of this area has received little attention, although the Coorong Lagoon area on the landward side is relatively well documented. On the high wave energy beaches of Younghusband Peninsula, it is likely there exists a paucity of species, with small invertebrates such as amphipods and isopods being most common. Known bivalve species include the commercially important Goolwa Cockle (Plebidonax deltoides). Fish species such as Mulloway (Argyrosomus hololepidotus) are thought to spawn in this area, with the juveniles subsequently moving into the lagoon nurseries. Biological Rich Diversity of Macroalgae (Seaweeds) The lower South East as a region contains one of the richest floras of marine macroalgae or seaweeds in the world. This is primarily due to the fact that this region is transitional, spanning both, the eastern cold-water Maugean biogeographical region (east of Robe) and the western, warmer element of the Flindersian (west of Robe). Coastal Wetlands of National Importance A Directory of Important Wetlands in Australia (ANCA 1996) list the following coastal wetlands of national importance along the South East coast: 1. The Coorong, Lake Alexandrina and Lake Albert 2. Butchers and Salt Lakes 3. South East Coastal Salt Lakes (Lake Robe, Lake Eliza, Lake St Clair, Lake George) Page 241 SOUTH-EAST COAST REGION 4. Ewens Ponds 5. Piccaninnie Ponds The variable coastal scenery of the South East is generally considered to be spectacular. "Geological Monuments" Southern Right Whale (Eubalaena australis) The endangered Southern Right Whale (Eubalaena australis) is often sighted each year along the South East coast in the winter months, from May-June. This region is probably part of the migratory path of whales which tend to move from the cooler waters of Tasmania, via Encounter Bay and Kangaroo Island, to the warmer waters of the Head of the Great Australian Bight, where they give birth and nurse their young (J.Ling, SA Museum, pers.comm). 1.2 Physical Coastal Upwellings The coastal upwellings of the South East are a highly significant physical and ecological process. The upwellings along this region represent the most significant coastal upwellings to be found along the whole of the Southern Australian coastline, and are due, in part, to the meterological conditions of the region. As a major source of nutrients to coastal ecosystems, they provide the essential basis for much of the region's highly productive coastal fisheries. Three centres of upwelling have been identified in the South East region: Robe, Southend and Port MacDonnell (Lewis 1981). Geology The geology of the South East coast is of immense significance both nationally and internationally. Indeed, "it must be concluded that the whole of the South East coast is of immense geological significance, not only for reasons of uniqueness but also because most of the features are not localised but cover extensive areas. The South East of South Australia is the only known area in the world which has preserved a complete record of late Pleistocene sea-level changes as stranded sand dune ridges. Thus, the South East coast holds the key to the geological and geomorphological history of the Pleistocene, which is of concern to geologists and geomorphologists studying this time period during which a large part of the present landscape was moulded."54 There are 15 areas of geological significance in the South East region which are associated with the coastline or offshore waters. These areas have been identified and recognised as "geological monuments" by the South Australian Museum and the Geological Society of Australia, and include the following sites: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 The Coorong (carbonate lakes) Taratap Rocks Guichen Bay Conservation Park (including Cape Thomas) Baudin Rocks Conservation Park (Godfrey Islands) Cape Dombey (coastal features, e.g. blowhole, arch in aeolianite) Little Dip Conservation Park Beachport Conservation Park, Cape Martin, Cowrie and Penguin Island Canunda National Park and Cape Buffon Carpenters Rocks to Cape Banks, including Admella Dunes Blackfellows Caves Nene Valley (dune area) Douglas Point Middle Point Cape Northumberland Stony Point (Flint Point) Further details of these areas are supplied in the relevant regional biounit descriptions below. 2 SIGNIFICANT CULTURAL HISTORICAL FEATURES AND The following description of Aboriginal and European history along the South East coast is necessarily brief and selective. The aim is to give the region a historical perspective with emphasis on coastal and maritime history. Only details of Aboriginal historical and cultural sites that have been published in the available literature are described. Aboriginal sites, objects and remains are protected under the South Australian Aboriginal Heritage Act (1988), and a register of such sites, objects and remains is kept with the Aboriginal Heritage Branch of the South Australian Department of Environment, Heritage and Aboriginal Affairs. 54 From South East Coast Protection District Study Report (UEPG 1982). Page 242 SOUTH-EAST COAST REGION 2.1 Aboriginal The Aboriginal history of the South East is highly complex and difficult to summarise easily. At the time of European settlement, however, there were three known tribes occupying land along the coast: 1 Tanganekald, who lived in the Coorong region, from the Murray Mouth to the Granites; 2 Meintangk, who lived along the coast from the Granites to Cape Jaffa and inland; 3 and the Buandik, who lived from Cape Jaffa to the Glenelg River (Victoria) and inland The South East and its coast is an extremely important Aboriginal heritage area. Remnants of Aboriginal activities such as middens occur all along the coast, and many of these, "provide a unique record of the events of the last 10,000 years and as such are of considerable scientific and heritage significance. Indeed it has been claimed that the diversity and preservation of many of these sites make them of national, if not international, importance."55 2.2 3 CURRENT CONSERVATION STATUS OF THE SOUTH EAST COAST The South East Province is the most underrepresented in terms of Marine Protected Areas (or MPAs) of all the coastal provinces in South Australia. As such, no Aquatic Reserves or large, multiple use Marine Parks have been declared in this region. The majority of MPAs in this region comprise `netting closures', many of which have generally not been formally recognised as MPAs (see Ivanovici 1985, McNeill 1991). However, this coast does contain three of the four Marine Sanctuaries which have declared in South Australia. All of these sanctuaries were established for the protection of a single species, the Southern Rock Lobster. Present MPAs in this region include: − Marine Reserves None − Marine Park None − − − Marine Sanctuaries Cape Jaffa (950 ha) Margaret Brock Reef (314 ha) Penguin Island and Rivoli Bay (40 ha) − − − − − − − − − − Netting Closures Murray Mouth Goolwa Guichen Bay (Robe) Robe Lakes Lake George Rivoli Bay Beachport – Salmon Hole Admella Dunes Port MacDonnell Brown Bay European Early Discoverers The South East coast was the first part of South Australia to be sighted by British subjects in 1800. Lieutenant James Grant, aboard the "Lady Nelson", viewed the coast and named Mt. Gambier, Mt. Shank, Cape Northumberland and Cape Banks. The process of exploring and settling the coast began in 1839. Robe was declared in 1847 and became the first port to facilitate safe shipping and the export of wool. Shipwrecks Some 46 shipwrecks occurred along the South East coast between 1844 and 1960. The most notable include the `Varoo’ at Cape Northumberland in 1856, the `Admella’ at Carpenter Rocks in 1859; the `Tenterden’ at Cape Northumberland in 1893 and the `Maria’ at Cape Jaffa in 1840. Wrecks in excess of 75 years old in Commonwealth waters are automatically protected by Commonwealth legislation, ie. Historic Shipwrecks Act 1976. Other wrecks may be protected if of significant value. Wrecks situated in State waters may be protected by proclamation under the State legislation, ie. Historic Shipwrecks Act 1981. 55 From South East Coast Protection District Study Report (UEPG 1982). Page 243 SOUTH-EAST COAST REGION – COORONG BIOUNIT XXVII MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE COORONG BIOUNIT The Coorong Biounit extends from Encounter Bay (near Middleton) to Lacepede Bay (Cape Jaffa) and includes the estuarine Coorong Lagoons located in the Coorong National Park. However, emphasis here is placed on the marine aspects of the lagoons and their connection with the Southern Ocean side of the Younghusband Peninsula. The biounit represents a total area of 1,290,715 ha. and a coastal distance of approximately 190 km. It faces in a southwesterly direction into the Southern Ocean. MARINE BIOGEOGRAPHY 1 OCEANOGRAPHY The gently curving sandy coast running from the Murray Mouth to Cape Jaffa represents a classic example of spatial variation in nearshore wave energy and beach surfzone morphology controlling the evolution, extent and nature of the entire coastal zone. Two factors are paramount in this evolution of this coast; (i) the gradient of the nearshore and (ii) the breaker wave energy. For the first 100km, the offshore gradient is 1:260, and then declines gradually. As a result the zone of significant deepwater wave attenuation widens from 5 to 38 km, causing wave power to decrease beyond 100km to the degree that it is nonexistent between 168 and 190km, the waves having lost all their energy crossing the low gradient nearshore zone. The longshore variation in breaker wave power has produced four zones within the Younghusband Subprovince: 1 2 3 4 Coorong I (0 to 100m from the Murray Mouth) characterised by high wave power. Coorong II (100m to 145km) characterised by moderate energy transition zone. Coorong III (145km-168km) a low energy transition zone (waves are the dominating force in all zones). Lacepede Bay (168km-190km) - zero breaker power has resulted in nearshore currents and locally generated wind waves being the dominating components of marine energy (Short & Hesp 1980). 2 GEOLOGY AND GEOMORPHOLOGY56 COASTAL The Coorong Biounit is dominated by sandy beach dunes, beach ridges and blowouts. Of particular geological note are the `Granites', north of Kingston, which are an unusual outcrop of coarse granite on a sandy beach. As the only visible evidence of Paleozoic bedrock along the entire South East coast, they are of considerable geological significance. The beach ridge plains of Lacepede Bay are also of considerable geomorpholgical significance, providing evidence of shoreline progradation over the past 500 to 7,000 years. The Murray River empties into the sea via a narrow but shifting mouth between the high dunes of Sir Richard and Younghusband Peninsulas. Holocene dune complexes extend from the mouth to Lacepede Bay. The largest and most well-known coastal landform along this biounit is the Coorong. The Coorong is a unique coastal landform with a shallow backwater estuary and ephemeral salt lake system that drains gradually into the sea behind the Younghusband Peninsula. Averaging about 1.2 km wide and over 145 km long, the Coorong is composed of a basal Pleistocene calcrete unit and an overlying dune sheet associated with the Holocene Marine transgression. The presence of water in the interdunal depression in the southern section is seasonal and the lagoon is replaced by a series of ephemeral lakes and swampy mud flats. 56 From South East Coast Protection District Study Report (UEPG 1982). Page 244 SOUTH-EAST COAST REGION – COORONG BIOUNIT 3 Inside the reefs, under moderate wave conditions, species such as Cystophora retorta, C.monoliformis, and Sargassum sonderi also occur. Margaret Brock Reef is the most westerly extent of the range of Macrocystis angustifolia and Durvillea potatorum along the southern temperate coastline of Australia. BIOLOGY Major Inshore Habitats − Major intertidal habitats in the region include sandy beaches, and some sections of rocky shore in the southern section of the biounit. − Of the total inshore subtidal habitats mapped in the biounit (170,935 ha), sandy bottoms comprise 75,497 ha (44.2%), reefs comprise 70,376 ha (41.2%), and seagrass meadows comprise 25,062 ha (14.7%). • − Major Benthic Communities • − Macroalgal Offshore rocky areas in this region, essentially consist of a series of parallel rocky reefs, which stretch offshore from the Coorong (from Encounter Bay to Cape Jaffa) from 11 metres (and deep offshore) on the broad continental shelf known as the Lacepede Shelf. These parallel reefs are submerged beach ridge systems, consisting of Pleistocene dune calcarenite, and form low profile reefs, subject to sand scour. At depths of 20m and deeper (down to 50-60 m), these low profile reefs are dominated by a sparse mixed red algal assemblage and bryozoans. At shallower depths and in areas of high wave energy, these reefs are dominated by Cystophora platylobium, and to a lesser extent, Seirococcus axillaris, Ecklonia radiata, and Carpoglossum confluens, with a mixed red algal understorey (eg. Areschougia congesta, Dictymenia tridens) and encrusting coralline algae (eg. Metagoniolithon). These high wave energy reefs are generally low in species of molluscs, crustaceans, and fish. In areas of moderate wave exposure (in southern Lacepede Bay, south of the Granites), these reefs are dominated by the fucoids, Scaberia agardhii, Cystophora retorta, and Cystophora gracilis and the red algal, Osmundaria prolifera. Margaret Brock Reef and North Reef (west of Cape Jaffa) comprises a series of low profile, limestone (ie. dune calcarenite) reefs, dominated by fucoids (such as Cystophora platylobium, and to a lesser extent, Perithalia caudata, Carpoglossum confluens, Seirococcus axillaris, Scytothalia dorycarpa, Ecklonia radiata), and a mixed red algal assemblage (eg. Sonderpelta coriacea), with Giant Kelp (Macrocystis angustifoliadominated) communities on the outer, more exposed parts of the reef system. Seagrasses Seagrass beds are absent along most of the offshore and nearshore coast off the Coorong, until south of the Granites. High wave energy and active sand movement probably prevent the colonisation of the sandy areas north of this area. Seagrass in the Coorong-Cape Jaffa region is principally located in nearshore region of southern Lacepede Bay, extending north along the coast to the Granites. Dense meadows of Posidonia australis (particularly in shallow waters), Amphibolus antarctica and Posidonia angustifolia occur in the bay from 0.5-12 metres. Patches of Posidonia coriacea and Heterozostera tasmanica also occur. Rivers and Estuaries − The Coorong. − River Murray. Coastal and Offshore Islands (or Reefs) − Offshore parallel reefs occur throughout the biounit. MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National and International Importance − The Coorong lagoons and Lakes Albert and Alexandrina have been identified as wetlands of national importance (see ANCA 1996) and have also been proclaimed as a Wetland of International Importance under the Ramsar Convention. Page 245 SOUTH-EAST COAST REGION – COORONG BIOUNIT The Coorong National Park, Carbonate Lakes, Finniss River/Currency Creek mouths area, Mud Islands Game Reserve, Mundoo Island and surrounding area, Salt Lagoon Conservation Park, Tolderol and Mosquito Points and Tolderol Game Reserves are listed on the Register of the National Estate. The area has also been identified as an area of international importance for shorebirds by Watkins (1993). − The Coorong is a shallow, saline to hypersaline, coastal lagoon system more than 100 km in length and separated from the Southern Ocean by a narrow sand dune peninsula known as the Younghusband Peninsula. The Coorong is connected to the sea via a narrow channel at the mouth of the Murray River (which is the principal source of freshwater for the Coorong). The Coorong Lagoon waters support a range of aquatic plants and animals and are an important feeding, breeding, spawning and nursery area for key commercial fish species as well as supporting one of the largest concentrations of waterbirds and migratory waders in Australia. The Coorong supports important nesting colonies of cormorants, herons, egrets, ibises and terns. Mosquito and Tolderol Points support a high diversity of waterbirds and are one of the best localities in the State for waders and terns. The Coorong lagoons are very important areas for migratory waders, and provide a drought refuge when central or eastern Australian wetlands dry out (ANCA 1996). The area is one of the ten major areas for large concentrations of waders in Australia, and one of the few south of the Tropic of Capricorn (ANCA 1996). During drought years, up to a quarter of a million migratory waders may be present during summer. In 1981, the Australasian Wader Study Group estimated the summer population of waders for the Coorong at 122 000, compared with a South Australian population of 200 000 and an Australian population of 403 000. The Coorong is a major migration stopover for shorebirds, with over 21 species recorded in the area. The ocean beach and foredunes adjacent to the Coorong National Park and Game Reserve is an important nesting area for the Australian endemic Hooded Plover (Charadrius rubricollis) and some 27 other species of seabirds and waders have been recorded here. Threatened species of waterbirds recorded in the area include the Orange-bellied Parrot, Neophema chrysogaster (Ne, Se), Little Tern, Sterna albifrons (Ne, Sv), Hooded Plover, Thinornis rubricollis (Nv, Sv) White-bellied Sea-Eagle, Haliaeetus leucogaster (Sv), Cape Barren Goose, Cereopsis novaehollandiae (Sv), Little Egret, Egretta garzetta (Sv), Australasian Bittern, Botaurus poiciloptilus (Sv), Musk Duck, Biziura lobata (Sv), Painted Snipe, Rostratula benghalensis (Sv), Latham’s Snipe, Gallinago hardwickii (Sv), Eastern Curlew, Numenius madagascariensis (Sv), Fairy Tern, Sterna nereis (Sv), Australasian Shoveler, Anas rhynchotis (Sr), Baillon’s Crake Porzana pusilla (Sr) and Spotless Crake P.tabuensis (Sr). A total of 90 species of waterbird have been recorded in the area: 33 are listed under treaties. Many species of waterbirds breed in the area, including the largest breeding colony of Pelicans, Pelecanus conspicillatus, in the world (and the only area in South Australia where Pelicans breed annually). The lagoons itself contains important breeding sites for Crested Tern Sterna bergii, Fairy Tern and Chestnut Teal, Anas castanea. A total of 24 species of marine and freshwater fish have been recorded from the inland waters of the Coorong, including the following economically important species, Mulloway, Argyrosomus hololepidotus, Yellow-Eye Mullet, Aldrichetta fosteri, Greenback Flounder, Rhombosolea tapirina, Australian Salmon Arripis truttacea, and Black Bream, Acanthopagrus butcheri. Other commercially important species in the area include the Goolwa Cockle, Plebidonax deltoides, which provides the major source of cockles for bait in south east Australia. − The Coorong National Park and Game Reserve itself is an important area as it contains a representative sample of coastal and salt-influenced terrestrial habitats as well as an unusual set of aquatic habitats in the Coorong Lagoon and ephemeral lakes, which are an important ecological (and aesthetic) component of the region. The empheral salt lakes are highly productive ecosystems and are of unusual geological and biological significance, and are actively forming unique associations of carbonate minerals and dolomite muds. The hydrology of the Coorong Lagoons is determined by a complex interaction of water from a number of sources including sea water, the River Murray, rainfall and groundwater. Page 246 SOUTH-EAST COAST REGION – COORONG BIOUNIT Lloyd & Balla (1986) considered this area to be of outstanding environmental value and recommended that it be given status as a wetland reserve. The Coorong National Park and Game Reserve are on the Register of the National Estate. − Butchers Lake and adjacent salt lakes have been identified as wetlands of national importance (see ANCA 1996). The area comprises three shallow lakes on the inland side of coastal dunes in Lacepede Bay, approximately 7km south west of the township of Kingston. The three lakes act an a important refuge for waterbirds in summer or during drought and is one of the few known habitats of the nationally endangered Orangebellied Parrot, Neophema chrysogaster (Ne, Se) (ANCA 1996). The area also contains some of the last remaining significant stands of coastal vegetation between the Coorong Lagoon and the township of Robe. A total of 16 species of waterbird have been recorded in the area: 3 are listed under treaties. The area is conserved within the Butchers Gap Conservation Park, which is listed on the Register of the National Estate. Other Areas of Recognised Conservation Significance − Lacepede Bay. This bay contains extensive beds or meadows of seagrasses such as Posidonia australis, Amphibolis antarctica and Heterozostera tasmanica, which are ecologically important as nursery and feeding areas particularly for species of fish and crustacea. Leafy Sea Dragons, Phycodurus eques, have been recorded on offshore reefs off the Kingston jetty (B.Lowry pers.comm.). In this region, the economically important Southern Rock Lobster (Jasus edwardsii) also forages in these seagrasses. Lacepede Bay was recommended as a scientific reserve by the Southeast Coast Protection Board (1982). − Cape Jaffa is located on the southern headland of Lacepede Bay and is a designated Marine Sanctuary for Southern Rock Lobsters (CONCOM workshop designation as a Marine Reserve). The reserve was declared in 1971 and proposed by the rock lobster fishing industry. Removal of juvenile Southern Rock Lobster is prohibited within 1 km of the High Water Mark of the defined area. The area is also a popular diving location and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). − Margaret Brock Reef is located west of Cape Jaffa and is a designated Marine Sanctuary for Southern Rock Lobsters (CONCOM workshop designation as a Marine Reserve). The reserve was declared in 1971 and proposed by the former SA Department of Fisheries. Removal of Southern Rock Lobster is prohibited within 1 km of the lighthouse on Margaret Brock Reef. The area is also a popular diving location and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). − The Pinnacles. Cape Jaffa is protected by a reef running in a line from the point south of the jetty, seaward for a distance of 5-6kms, to the old lighthouse platform on Margaret Brock reef. The reef is recognised locally for its bommies and an abundant range of marine life, including prolific fish life (such as schools of Banded Sweep, Silver Drummer, Leather Jackets, Cale Fish, Parrot Fish, Wrasses and also, sightings of Leafy Sea Dragons). The area is also a popular diving location and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). − The endangered Southern Right Whale (Eubalaena australis) is often sighted each year along this region of coast from May-June. This region is probably part of the migratory path of whales which tend to move from the cooler waters of Tasmania, to the warmer waters of the Head of the Great Australian Bight, where they give birth and nurse their young (J.Ling, SA Museum, pers.comm.). Page 247 SOUTH-EAST COAST REGION – COORONG BIOUNIT 1.2 Physical − The `Granites' north of Kingston, is the only visible evidence of Paleozoic bedrock along the entire south-east coast. − Beach ridge plains of Lacepede Bay are evidence of shoreline progradation over the past 500 to 7000 years and are of considerable geomorphological significance (i) − The Murray River empties into the sea via a narrow but shifting mouth between the high dunes of Sir Richard and Younghusband Peninsulas. Geological Monuments − Coorong: carbonate lakes. − Taratap Rocks: adamellite outcrop with diverse textures. The quarry is on Crown Land and there is an outcrop on the beach to the northwest. 2 2.1 OTHER VALUES Commercial Fisheries The main single species fishery in this region is the Southern Rock Lobster (Jasus edwardsii) industry. Together Cape Jaffa and Kingston have the third largest concentration of Southern Rock Lobster fishing boats in the South East, representing approximately 20% of the total number of boats for the Southern Zone. Southern Rock Lobster This biounit encompasses 2 fishing zones: the offshore waters of the Coorong (Fishing Zone 50) and the nearshore waters of the Coorong (Fishing Zone 51). In 1995/96 and 1996/97 a total of 16 and 13 licensed operators fished in the offshore waters of the Coorong Biounit (ie. Fishing Zone 50), catching approximately 43,529 and 31,894 kg of lobsters, respectively (or 0.85% and 0.62% of the total catch for Southern Rock Lobster in South Australian waters). In contrast, in the nearshore waters there is at least twice as much production. In 1995/96 and 1996/97 a total of 19 and 16 licensed operators fished in the nearshore waters of the Coorong (ie. Fishing Zone 51), catching approximately 94,490 and 91,905 kg of lobsters, respectively (or 1.85% and 1.80% of the total catch for Southern Rock Lobster in South Australian waters). Abalone Negligible Blacklip Abalone and Greenlip Abalone is presently commercially harvested within the Coorong Biounit, apart from the southern waters near Cape Jaffa (see Canunda Biounit). Marine Scalefish Fisheries The Coorong Biounit principally encompasses 2 fishing zones: Fishing Zones 50 and 51. During 1995/96 and 1996/97, 24 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught commercial marine scalefish species from the inshore Coorong waters of this biounit (ie. Fishing Zone 51). License holders expended approximately 836 and 829 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 51) represented 129,998 kg in 1995/96 and 142979 kg in 1996/97(or 1.25% and 1.41% of the total catch for the marine scalefish fishery in South Australian waters). In the offshore Coorong waters of this biounit (ie. Fishing Zone 50), a total of 17 and 13 licensed operators fished 559 and 448 days in this region in 1995/96 and 1996/97, catching approximately 238,182 and 144,414 kg, respectively (or 2.29% and 1.42% of the total catch for the marine scalefish fishery in South Australian waters). A well established fishery along the Coorong Beach is the removal of the Goolwa Cockle (Plebidonax deltoides) (400 tonnes/year). Commercial netting for Mulloway (Argyrosomus hololepidotus) and Shark also occurs along the Coorong beach. Around Kingston and the Granites, a small amount of Australian Salmon (Arripis trutta esper) trolling occurs, mainly to provide bait for lobster (5 tonnes/year). Shark and Abalone (Haliotis rubra and H.laevigata) are also taken from the waters of the South East coast. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: Kingston: 21 Southern Rock Lobster licenses, 1 unrestricted marine scalefish license. Page 248 SOUTH-EAST COAST REGION – COORONG BIOUNIT 2.2 Aquaculture A research and development site has been approved for trialing salmon aquaculture in this region near Cape Jaffa and another site has been sought near Robe. Additional interest has been expressed in undertaking trials for kelp culture in Lacepede Bay and around Cape Jaffa. No other marine-based aquaculture interests current exists in this region. The South East Aquaculture Management Plan (Gilliland 1996) proposes limited aquaculture development in this region: Coorong Policy Area − Coorong Zone (ie. waters adjacent to the Coorong National Park, to the Murray Mouth) – licenses will not be considered within this zone. Kingston Policy Area − Cape Jaffa Aquaculture Zone (ie. inshore Cape Jaffa) – licenses will be considered for a maximum of 40 ha of aquaculture in this zone. Industry identified this area as being suitable for aquaculture, especially finfish culture. − Kingston Exclusion Zone (ie. inshore waters adjacent to Butchers Gap and Bernouilli Conservation Parks, Granites) – licenses will not be considered for aquaculture in this zone. − Kingston Zone (ie. remaining waters in Lacepede Bay, from north of the Granites to Cape Jaffa) – licenses will not be considered for aquaculture greater than 60 ha, or for intertidal oyster culture or within 250m of the Cape Jaffa jetty. 2.3 − Tourism − Kingston: sailing, boating, diving, swimming, jetty fishing, historic area. − Kings Camp: swimming, fishing, scenic area. − Younghusband Peninsula: whale watching, Coorong National Park (beach fishing, camping, bird watching, off-road vehicles), Murray Mouth. − Lacepede Bay: Butchers Gap Conservation Park, camping, fishing, scenic area. − SCUBA diving: Margaret Brock Reef and North Reef, near Cape Jaffa, are popular dive spots in the region and are listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). North Reef is a 4-5km reef which runs parallel to shore starting from Margaret Rock, towards Kingston. The whole reef is characterised by bommies and abundant marine life, including Southern Rock Lobster. 2.4 − Recreation and Tourism Fishing − − Coorong and Murray Mouth: boat and shore fishing. Major species: Black Bream, Sand Flathead, Yelloweye Mullet, Australian Salmon, Mulloway and Flounder. Fishing in this area is centred mainly around the Murray Mouth. Kingston and The Granites: boat, beach and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook,Garfish, Southern Rock Lobster, Tommy Rough and Trevally. Cape Jaffa: beach, rock, boat and jetty fishing. Major species: King George Whiting, Sand Flathead, Yelloweye Mullet, Australian Salmon, Snapper, Mulloway, Snook, Garfish, Tommy Rough, Trevally, Toothbrush Leatherjacket and Silver Drummer. 2.5 boating, jetty Scientific Research and Education Fisheries research in this area includes, regular catch and effort monitoring of the major commercial fisheries in the region, both marine (Southern Rock Lobster, Abalone and marine scalefish) and inland waters; and regular research and monitoring of fish stocks of Southern Rock Lobster . Adjacent Land Use National and Conservation Parks − Coorong National Park (46,745 ha) (SANPWS 1988). − Butcher Gap Conservation Park, Lacapede Bay (178 ha). − Bernouilli Conservation Park (near Cape Jaffa) (242 ha). Page 249 SOUTH-EAST COAST REGION – COORONG BIOUNIT Agriculture/Industry Shipwrecks Major industries along the coast involve fishing and fish processing. There are also some brown coal deposits near Kingston that may become in demand in the future. Four wrecks are known to be located in the region and are protected under the Commonwealth legislation (ie. Historic Shipwrecks Act 1976). These include: Most adjacent land is used for livestock grazing and cereal growing. − `Margit’: lost in 1911 is located offshore from the Coorong National Park. Drain outlets at Blackford (north of Kingston), Maria Creek at Kingston (possibly impacting on the seagrass meadows) and at Butchers Gap (south of Kingston). − `Margaret Brock’: a three-masted wooden barque built at Hobart Town inn 1848, and wrecked on the Margaret Brock reef in 1852 whilst on its way to Melbourne from Port Adelaide. The remains are located in 2-10 metres of water on the Margaret Brock Reef. A bell from the ship has been recovered. − `Fanny’: a brig that ran ashore along the Coorong Ninety Mile Beach in 1838 during a gale. Her captain's favourable description of the Coorong and members of the Ngarrindjeri who helped him to safety was one of the first to be reported in the early days of the colony. − `Maria’: wrecked at Lacepede Bay in 1840. This wreck had profound effects on race relations in the colony: the surviving Europeans were killed apparently in retribution for interfering with some of the Milmenrura women and some of the guilty persons were later executed under instruction by Governor Gawler. This dramatically illustrated to the Milmenrura their lack of power when dealing with the Europeans fire power, and the eventual invasion of their country seemed inevitable. The dunes opposite Dodds Landing is the burial site of the survivors of the shipwreck and of those hanged in retribution for their killing. − Additionally there are 11 other wrecks that are believed to be located in this area, many of which are of significant historical value and are also protected under Commonwealth legislation: `Maria’ (lost in 1840), `St Vincent’ (lost in 1844), `Sophia Jane’ (lost in 1844), `Mariner’ (lost in 1845), `Victoria’ (lost in 1846), Gazelle’ (lost in 1848), `Mozambique’ (lost in 1854), `Halcyon’ (lost in 1857), `Agnes’ (lost in 1876), `Kingston’ (lost in 1895), and the `Elsie’ (lost in 1901). Urban Centres − Kingston (population 1,367). 2.6 Features Significant Cultural and Historical Aboriginal Aboriginal occupation of the Coorong area was based on a rich and complex marine economy which had evolved above a period of 8000 years. The Coorong was the territory of a single tribe of the Ngarrindjeri people, called the Tanganekald. A large number of shell middens and mounds, cooking ovens, campsite and cemeteries are found both near the ocean beach and along the lagoon shoreline in the Coorong. Other significant sites are the places where crossings across the Lagoon occurred. These crossings formed a vital communications link to the `mainland' for each clan of the Peninsula and as such, the importance of this area cannot be overstated. The physical remains of the highly cohesive and viable Aboriginal settlement of the Coorong is recognised as one of the most outstanding records of coastal adaptation in temperate Australia and as such are considered of international as well as national significance (Coorong National Park and Game Reserve Management Plan). European The Coorong region was a major section of the overland stock route, mail coach route, migrant route and the telegraph line route between Melbourne and Adelaide. As such, it is an area of significant historical and cultural value at a state level. Page 250 SOUTH-EAST COAST REGION – COORONG BIOUNIT 3 − − − − − Marine Reserves None (although, the Coorong Lagoons are within the boundaries of the Coorong National Park) Marine Parks None Marine Sanctuaries Cape Jaffa (950ha), southern headland of Lacepede Bay (removal of Southern Rock Lobster is prohibited within 1 km of the High Water Mark of the defined area) Margaret Brock Reef (314ha), west of Cape Jaffa (removal of Southern Rock Lobster is prohibited within 1 km of the lighthouse on Margaret Brock Reef). Lacepede Bay-Cape Jaffa-Margaret Brock Reef 58 59 − Netting Closures Murray Mouth (waters of the sea within 500 metres of the Murray Mouth, from the south east corner of Younghusband Peninsula to the south west corner of Sir Richard Peninsula). − Goolwa (within 150 m of all barrages). 4 AREAS OF HIGH CONSERVATION VALUE IN THE COORONG BIOUNIT Coorong National Park − Mulloway, Goolwa Cockle, Shark, Calamari, Snapper, Snook, Australian Salmon), social (numerous aboriginal sites-Sir Richard Peninsula-Ngarrindjeri occupation, grave sites, aesthetic values, shipwrecks-`Fanny’, `Margit’, recreational fishing, camping, 4WD’s), national/international (Register of the National Estate-Coorong National Park, Wetlands of National Importance-Coorong Lakes and Lagoon, RAMSAR Wetland of International Importance), practicality (insulation, accessibility, compatibilityadjacent to Coorong National Park and Game Reserve, Sir Richard Peninsula Coast Protection Board Reserve). CURRENT CONSERVATION STATUS OF THE COORONG BIOUNIT 57 Prime IUCN Conservation Values: biodiversity, aesthetic, cultural values (IUCN Category III). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (representativeness, unique coastal dune barrier of the Coorong Lagoon, record of Pleistocene sea level change, wide range of coastal and estuarine habitat types, geological monumentscarbonate lakes), ecological (range of coastal marine habitats, River Murray estuary-largest estuary in Australia, internationally important site for waterbirds and migratory waders, Hooded Plover nesting areas, seabird breeding colonies-Little Penguins, Crested Terns, Caspian Terns, Little Terns, Silver Gulls, White-breasted Sea Eagles, Little Falcons, numerous coastal seabird and waders), economic (marine scalefish- Prime IUCN Conservation Values: biodiversity, cultural, social values (IUCN Category IA). IUCN Identification Criteria: naturalness (not subject to human induced change), biogeographic (transition zone between the Maugean and the Flindersian biogeographical regions, coastal upwelling, `Granites’, Lacepede Bay beach ridge plains), ecological (high diversity of fauna and flora, wide range of community and habitat types, extensive seagrass meadows, endangered Leafy Sea Dragon, kelp forests, cetaceans, endangered Southern Right Whale, Orangebellied Parrot), economic (fisheries-Southern Rock Lobster, Abalone, Australian Salmon, Shark, tourism-Kingston), social (shipwreck`Maria’ and burial site, `Margaret Brock’), scientific (Southern Rock Lobster research), national (Butcher’s Gap Conservation ParkRegister of the National Estate, Wetland of National Importance), practicality (accessibility, insulation, compatibilityadjacent to Cape Jaffa Rock Lobster Sanctuary, Butcher’s Gap Conservation Park). 58 57 An extension of the existing boundaries of the Coorong National Park, to include the coastal reserve of Sir Richard Peninsula, has recently been proposed by Edyvane et al. (1996), in order to manage the Lower Murray estuary. Due to it’s unique marine flora and fauna, Margaret Brock Reef was recommended as an Aquatic Reserve by the South East Coast Protection Board (UEPG 1982). 59 Lacepede Bay was recommended as a scientific reserve by the South East Coast Protection Board (UEPG 1982). Page 251 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT XXIX MARINE BIOGEOGRAPHY AND CONSERVATION VALUES OF THE CANUNDA BIOUNIT The Canunda Biounit extends south from Cape Jaffa to Cape Banks and covers an area of 233,897 ha and a coastal distance of 140 kilometres. It is oriented in a southwesterly direction into the Southern Ocean MARINE BIOGEOGRAPHY 3 BIOLOGY Major Inshore Habitats 1 OCEANOGRAPHY The coast of this biounit is exposed to both low and high energy wave energies. Low wave energy occurs in Wright, Guichen and Rivoli Bays due to attenuation by offshore reefs. The straight coast of Canunda, however, has a very high energy dissipative surfzone due to the general absence of reefs. − Major intertidal habitats in the region include mostly exposed limestone rocky shores, bays and sandy beaches. − Of the total inshore subtidal habitats mapped in the biounit (55,887 ha), limestone reefs comprise 50,552 ha (90.5%), sandy bottoms comprise 5,333 ha (9.5%), and seagrass meadows comprise 2 ha (<0.1%). The coastline from Cape Buffon to Cape Banks receives the highest break of wave energy in the South East (Short & Hesp 1984). Waters in this biounit are cold temperate and typified by the localised, regular, seasonal cold, nutrient-rich upwellings near Robe and South End (Lewis 1981). Mean sea surface temperatures vary from 140C in winter to 180C in summer (decreasing to 11-120C under the influence of the upwellings). The upwellings are significant along the southern Australian coastline and contribute directly to the considerable productivity of the region. 2 GEOLOGY AND GEOMORPHOLOGY60 COASTAL A highly irregular coastal topography, producing marked variations in wave attenuation and refraction across the nearshore, and breaker wave power at the shoreline. The resulting highly variable breaker wave power, coupled with dunerock exposures, has generated a variable shoreline morphology including rocky sea-cliffs fronted by intertidal shore platforms and sandy beaches ranging from low energy to very high energy. There are both stable and unstable transgressive dune systems. Five coastal geomorphological subprovinces are identifiable within the dunerock coast, each representing a particular combination of nearshore morphology, breaker wave energy and backing dunerock-barrier morphology. For further details refer to Short and Hesp (1984). 60 From South East Coast Protection District Study Report (UEPG 1982). Major Benthic Communities • − Macroalgal Flat limestone platform reefs (comprising dune aeolianite) dominate most of this region (eg. Rivoli Bay, Guichen Bay), from 8 metres (and deeper). Sandy areas occur close to shore, and also in deeper areas between reefs (approximately 12 metres), and typically comprise well-worked coarse to medium sand, characteristic of high wave-energy conditions. In exposed areas (13-22 metres depth), kelp forests occur, dominated by Macrocystis angustifolia (Giant Kelp) and to a lesser extent, Cystophora platylobium, Carpoglossum confluens, Ecklonia radiata, along with species of Caulerpa (particularly C.longifolia, C.flexilis, C.brownii) and a high diversity of red algae, and calcareous algae and animals. Importantly, species of Caulerpa appear to play a key role in consolidating sediments on the platform reefs. In sheltered rocky areas, species of red algae and Caulerpa (particularly C.flexilis, C.brownii, C.obscura) continue to dominate, along with Cystophora monoliformis and to a lesser extent, C.siliquosa, Scaberia agardhii, Acrocarpia paniculata, Perithalia caudata and species of Codium. Significant forests of Macrocystis occur in the lee of nearshore reefs, and just offshore, at Cape Dombey (southern Guichen Bay), Cape Buffon (southern Rivolvi Bay), and Cape Banks, but are largely absent along the Canunda Beach region. Macrocystis occurs down to 35m but is generally sparse at depths greater than 25m. Page 252 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT • − Seagrasses − Lake George and Lake Eliza are two of the remaining wintering grounds in the South East of the State for the Orange-bellied Parrot, Neophema chrysogaster and Lake George is an important wintering ground for the Doublebanded Plover, Thinornis bicinctus. Threatened species of waterbirds recorded in the area include the Orange-bellied Parrot (Ne, Se), Musk Duck, Biziura lobata (Sv), and Latham’s Snipe, Gallinago hardwickii (Sv). A total of 42 species of waterbirds have been recorded in the area: 14 are listed under international treaties (ANCA 1996). Resident waterbirds listed under treaties include the Great Egret, Ardea alba and Cattle Egret, A.ibis. Black Swans, Cygnus atratus breed on the lakes. Lake Eliza and Lake George have been identified as wetlands of international importance for shorebirds by Watkins (1993). Lake George is a spawning area for two species of marine fish, the Yellow-Eye Mullet, Aldrichetta forsteri, and Flounder. − Lake Frome and Mullins Swamp have been identified as wetlands of national importance (see ANCA 1996). The area, adjacent to the Canunda National Park and township of South End, consists of a very shallow permanent coastal plain swamp that supports large patches of fringing aquatic vegetation interspersed by stretches of open water. From Mullins Swamp, water passes into Lake Frome, and ultimately into the sea at the township of South End. Lake From and Mullins Swamp provide excellent waterbird habitat and together are considered to be one of the major waterbird localities in the lower south east of the State (ANCA 1996). Threatened plant species include Melaleuca squarrosa (Sr). Threatened species of waterbirds recorded in the area include the Musk Duck, Biziura lobata (Sv), Lewin’s Rail, Rallus pectoralis (Sv), Latham’s Snipe, Gallinago hardwickii (Sv), Painted Snipe, Rostratula benghalensis (Sv), Australasian Bittern, Botaurus poiciloptilus (Sv), Australasian Shoveler, Anas rhynchotis (Sr), Baillon’s Crake, Porzana pusilla (Sr) and Spotless Crake P.tabuensis (Sr). A total of 53 species of waterbirds have been recorded in the area: 11 are listed under international treaties. A total of 26 species of waterbirds breed in the area, including Hardhead, Australasian Bittern, Lewin’s Rail and Baillon’s Crake; colonies of Pied Cormorant, Phalacrocorax melanoleucos, Nakeen Night Heron, Nycticorax caledonicus, Straw-necked Ibis, Threskiornis spinicollis, Australian White Ibis, T.molluca, and Whiskered Tern, Chlidonias hybridus. Seagrass habitats in this region are present, but rare, being mainly confined to the shallow, sheltered areas of Guichen Bay (Godfrey Islands), Nora Creina, and southern Rivoli Bay, Penguin Island), and sheltered interreefal areas. Seagrasses occur in patches or as sparse meadows and dominated by Posidonia coriacea, P.australis, Amphibolus antarctica and Heterozostera tasmanica. Coastal and Offshore Islands (or Reefs) − Margaret Brock Reef (off Cape Jaffa). − Baudin Rocks or Godfrey Island (Guichen Bay). − Penguin Island (off Cape Martin, Rivoli Bay). MARINE CONSERVATION VALUES 1 1.1 SIGNIFICANT BIOLOGICAL PHYSICAL FEATURES AND Biological Coastal and Marine Wetlands of National Importance − The coastal salt lakes of Lake Robe (399 ha), Lake Eliza (4683 ha), Lake St Clair (2566 ha) and Lake George (5916 ha), have been identified as wetlands of national importance (see ANCA 1996). The four lakes are situated on the coastal plain between the townships of Robe and Beachport, in the interdune corridor between the present dune ridge (to the west) and relict coastal dune (to the east), and are surrounded by small freshwater ephemeral wetlands. Lake George is a deep estuarine lake intermittently connected to the sea. The coastal wetlands act as a refuge for waterbirds in the summer or drought (ANCA 1996). The lakes and groundwater soaks provide a diverse selection of vegetation structures and wetland habitats for waterbirds. Page 253 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT east. Limestone rises separated by long sandy beaches occur at intervals along the 11 kilometres coastal strip between Cape Lannes and Errington Holes. The coastal strip is between 750m and 2 km wide at points. A number of small lakes occur, most of which are brackish. Two contain permanent freshwater, providing an important water bird habitat. Typical samphire vegetation (Sarcocornia sp.) and the South Australian Swamp Paper Bark occurs around the brackish lakes. It is a significant area as it conserves remnant coastal vegetation and a chain of small lakes, and provides habitat for endangered and vulnerable bird species. Other significant features include the partially eroded dune rock of the Robe Range, fossilised tree roots, rocky headlands that contain habitat for roosting and nesting birds, sandy beaches with extensive dunal systems (major tourist attraction), stabilised dunes that provided habitat for birds and mammals as well as providing protection to the small coastal lakes. The chain of small lakes is an uncommon feature and not well conserved in the reserve system. The park is on the Register of the National Estate. The area is also a popular reef diving location, with many giant deep overhangs and swimthroughs, and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). Resident waterbirds listed under treaties include the Great Egret, Ardea alba, Glossy Ibis, Plegadis falcinellus and Painted Snipe. Mullins Swamp is a Wildlife Sanctuary. Other Areas of Recognised Conservation Significance • Margaret Brock Reef − This limestone reef (like other reefs in this biounit) possesses unique flora and fauna related to its position in the transition zone between the Maugean Subprovince and the remainder of the Flindersian Province. Consequently this area is reknown for its rich diversity of marine flora and fauna. It has extensive subtidal forests of the Giant Kelp (Macrocystis angustifolia) and just below low tide level, extensive zones of Bull Kelp (Durvillea potatorum). Both these communities are typical of cold-water rough water coasts of the Maugean Subprovince. The reef is presently a Marine Sanctuary for the Southern Rock Lobster (Jasus edwardsii) with removal of lobsters prohibited within 1km of the lighthouse on the reef. Due to it’s unique marine flora and fauna, Margaret Brock reef was recommended as an Aquatic Reserve by the Southeast Coast Protection Board (1982). The area is also a popular diving location and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). • − • − Baudin Rocks Conservation Park (Guichen Bay) This park (also known as Godfrey Island), comprises several small, rocky islands which are set aside to protect a breeding colony of Crested Terns (Sterna bergii) and Little Penguins (Eudyptula minor). Within Guichen Bay, there are large forests of Giant Kelp (Macrocystis angustifolia) which act as shelter for numerous species of fish, molluscs and crustacea (including Southern Rock Lobster). The kelp also contributes ecologically to the marine ecosystem via detritus which following decay becomes incorporated into the food web. Intertidal and subtidal seagrass beds in this bay (and other bays in the region) are also important for the Southern Rock Lobster which shelter and feed in these areas. Baudin Rocks Conservation Park is on the Register of the National Estate. Little Dip Conservation Park: A large coastal park featuring a complex sand dune system with cliffs, shore platforms, reefs and islets to the west and large salt lakes to the • Nora Creina Bay − This bay was recommended as an aquatic reserve by the South East Coast Protection Board (1982), with consideration to be given to permitting line fishing in the reserve as a number of migratory species frequently move through the area. The bay is also a regular spot for marine education and scientific studies by the University of Adelaide and SA Herbarium. • − Beachport Conservation Park Beachport Conservation Park is situated between the Southern Ocean and Lake George. A diverse range of habitats exist within the park, including mobile sand dunes and a freshwater lake known as Two Lakes. The adjoining coastal and lake environments supports approximately 200 species of birds. The margin of Lake George is a particularly important area for migratory waders such as the Grey Plovers (Pluvialis squaterola), Mongolian Sand Dotterels (Charadrius mongolus), Green shanks (Tringa nebularia) and Bar-tailed Godwits (Limosa lapponica). The park also contains extensive areas of Aboriginal middens. The park is on the Register of the National Estate. The area is Page 254 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT also a popular reef diving location, with many swimthroughs, gutters and ledges, and is listed in `Dive South Australia: The Best Dive Sites in South Australia’ (Diving Industry Association of South Australia). • − • − Penguin Island Conservation Park and Rivoli Bay Penguin Island is a breeding ground for Little Penguins, Crested Terns, Silver Gulls (Larus novaehollandiae) and Black-faced Shags (Leucocarbo fuscesens). Australian Sea Lions are occasional visitors. Penguin Island Conservation Park is on the Register of the National Estate. The limestone reef in this area is presently a Marine Sanctuary for the Southern Rock Lobster (Jasus edwardsii) with removal of lobsters prohibited within 100m of any part of the coast of Penguin Island and that portion of Rivoli Bay as defined in the proclamation. Because of its public accessibility and tourism potential to Beachport, Penguin Island was recommended as an Aquatic Reserve by the South East Coast Protection Board (1982). Canunda National Park This area was set aside to preserve and protect a representative sample of the coastal environment of the South East. The northern coast of this park contains spectacular limestone outcrops and offshore reefs. The remainder of coastline consists of a long sandy beach and a complex system of mobile dunes which are the most massive (up to 60m high, and extending 5km inland) and unstable dune systems in the South East region (Short & Hesp 1980). The south coast beach is backed by low fore-dunes. There are a number of freshwater soaks supporting ephemeral swamp vegetation such as at Whale Rock and between Jacky Point and Number One Rock. Over the years the Ocean Beach at Canunda has seen many strandings of mainly vagrant marine mammals and oceanic birds. Other features include habitat for rare species and birds (Orange-bellied Parrot and the Swamp Antechinus), numerous Aboriginal middens, hearths, stone ovens and campsites and features associated with European settlement such as the Old Ellis Homestead. The park is on the Register of the National Estate. • − Cape Banks This area was recommended as an aquatic reserve by the South East Coast Protection Board (1982), with consideration to be given to prohibiting spearfishing and the taking of lobsters by divers, but the use of lobster pots to be permitted, owing to the importance of the area to the lobster industry. • − 1.2 Southern Right Whale (Eubalaena australis) The endangered Southern Right Whale (Eubalaena australis) is often sighted each year along this region of coast from May-June. This region is probably part of the migratory path of whales which tend to move from the cooler waters of Tasmania, to the warmer waters of the Head of the Great Australian Bight, where they give birth and nurse their young (J.Ling, SA Museum, pers.comm.). Physical − Presence of nutrient-rich coastal upwellings near Robe and South End. These upwellings are unique along the southern Australian coastline and contribute directly to the considerable productivity of the region. − The beach ridge plains of Lacepede, Guichen and Rivoli bays and the Pleistocene calcrete formations of the Robe range between Robe and Beachport are important geological and geomorphological areas. − Canunda beach is a spectacular high energy beach (see above). Geological Monuments − Guichen Bay Conservation Park (including Cape Thomas). On the Register of the National Estate. − Baudin Rocks Conservation Park (Godfrey Islands). On the Register of the National Estate. − Cape Dombey: coastal features such as the blowhole and the aeolianite arch. − Little Dip Conservation Park: includes part of Robe Dune Ridge. − Beachport Conservation Park, Cape Martin, Cowrie and Penguin Island. Beachport Conservation Park and Penguin Island are on the Register of the National Estate. Carpenters Rocks to Cape Banks, including Admella Dunes: Gambier Limestone with shore platforms - transgressive Holocene Dunes - cliff is retreating). − 2 2.1 OTHER VALUES Commercial Fisheries Page 255 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT The main single species fisheries in this biounit are the Southern Rock Lobster (Jasus edwardsii) and Abalone industries. Boats at Beachport, Carpenter Rocks, Robe, Nora Creina and Southend together account for nearly 48% of the total number for the Southern Zone. Of these, Robe and Nora Creina have approximately a third of the boat numbers within this biounit. Southern Rock Lobster This biounit is the most significant region for Southern Rock Lobster fishing in South Australia. The region encompasses 2 fishing zones: the waters from Cape Jaffa to Cape Martin (Fishing Zone 55) and the waters from Cape Martin to Nene Valley (Fishing Zone 56). In 1995/96 and 1996/97 a total of 85 and 78 licensed operators fished in the northern section of this biounit (ie. Fishing Zone 55), catching approximately 635,945 and 629,222 kg of lobsters, respectively (or 12.43% and 12.30% of the total catch for Southern Rock Lobster in South Australian waters). Similarly, in the southern section of this biounit, effort and production is also high. In 1995/96 and 1996/97 a total of 66 and 60 licensed operators fished in the southern section of the Canunda Biounit (ie. Fishing Zone 56), catching approximately 539,764 and 499,739 kg of lobsters, respectively (or 10.55% and 9.77% of the total catch for Southern Rock Lobster in South Australian waters). Within this one biounit, lobster catch for 1995/96 and 1996/97 represented approximately 22.99% and 22.07% of the total catch for Southern Rock Lobster in South Australian waters. Abalone This biounit represents some of the most significant areas for the commercial harvest of Blacklip Abalone in South Australia. Areas such as Rivoli Bay and the coastal reefs adjacent to Lake Bonney are particularly productive areas in this region. In 1994/95 and 1995/96 a total of 74,606 and 52,668 kg of Blacklip was harvested within this region (ie. MapCode 33A-C, 34A-D, 35A-E, 36A-C, 37AH, 38B-H, Cape Jaffa to Cape Banks region), which represented 51.9% and 36.9% of the total Blacklip Southern Zone catch (or 15.09% and 11.38% of the total catch for Blacklip in South Australian waters), but due to confidentiality constraints these figures are not available. commercial marine scalefish species from the northern section of this biounit (ie. Fishing Zone 55), respectively. License holders expended approximately 1922 and 1910 boat days effort fishing these waters during 1995/96 and 1996/97, respectively. The marine scalefish catch for this region (ie. Fishing Zone 55) represented 92,391 kg in 1995/96 and 56071 kg in 1996/97(or 0.89% and 0.55% of the total catch for the marine scalefish fishery in South Australian waters). In the southern section of this biounit, south of Cape Martin (ie. Fishing Zone 56), a total of 37 and 32 licensed operators fished 2,387 and 2,833 days in this region in 1995/96 and 1996/97, catching approximately 80,518 and 59,807 kg, respectively (or 0.77% and 0.59% of the total catch for the marine scalefish fishery in South Australian waters). There is a relatively small amount of salmon netting (a few tonnes) which is used chiefly as bait for lobster around Beachport. At the mouth of Lake George there are 1 or 2 commercial net fishers, targeting Sea and Yellow Eye Mullets, Mulloway and Australian Salmon. There is a substantial offshore marine fishery in this area especially at the shelf 100m-900m and around the submarine using deep lines for Blue Eye (Hyperoglyphe antarctica). scalefish edges at canyons Trevalla A large shark fishery at 20m-100m depth using large mesh gill nets exists mainly for School Shark (Galeorhinus australis) and Gummy Shark (Mustelus antarcticus). The south-east trawl fishery is also substantial in this biounit with 75% of the boats used being based at Beachport. Trawling occurs in the deep canyons for Orange Roughy (Hoplostethus atlanticus), and at 300m-1200m for Gem Fish and for Grenadier at the continental shelf. There is no inshore trawling mainly due to the rough bottom. Other commercial species include Tommy Ruff, King George Whiting and Garfish. Although license holders are not restricted to fishing in this biounit, the following licenses are registered in this area: − Southend: 1 abalone, 25 Southern Rock Lobster, 1 unrestricted marine scalefish. − Nora Creina: 1 Southern Rock Lobster. − Robe: 27 Southern Rock unrestricted marine scalefish. − Beachport: 22 Southern Rock Lobster. Marine Scalefish Fisheries The Canunda Biounit encompasses 2 fishing zones: Fishing Zone 55 and 56. During 1995/96 and 1996/97, 48 and 37 commercial licence holders (made up of Marine Scalefish and Restricted Marine Scalefish licence categories) caught Lobster, 2 Page 256 SOUTH-EAST COAST REGION – CANUNDA BIOUNIT − Carpenter Rocks: 14 Southern Rock Lobster. − Cape Jaffa: 15 Southern Rock Lobster, 2 unrestricted marine scalefish 2.2 − Aquaculture A research and development site has been approved for trialing salmon aquaculture in this region near Cape Jaffa and another site has been sought near Robe. Additional interest has been expressed in undertaking trials for kelp culture in Lacepede Bay and around Cape Jaffa. No other marine-based aquaculture interests current exists in this region. The South East Aquaculture Management Plan (Gilliland 1996) proposes limited aquaculture development in this region: Robe Policy Area − Robe Aquaculture Zone (ie. offshore Little Dip Conservation Park) – licenses will be considered for a maximum of 40 ha of aquaculture in this zone. − Robe Exclusion Zone (ie. inshore waters adjacent to Bernouilli, Baudin Rocks, Little Dip, Beachport Penguin Island Conservation Parks, Nora Creina Bay, Cape Buffon) – licenses will not be considered for aquaculture in this zone. − Robe Zone (ie. remaining waters, inshore and offshore, from Cape Jaffa to Cape Buffon) – licenses will be considered for aquaculture development greater than 60 ha, or for intertidal oyster culture. 2.3 Port MacDonnell Exclusion Zone (ie. inshore waters adjacent Canunda National park, Nene Valley and Piccaninnie Ponds Conservation Parks, including Carpenters Rocks and Blackfellows Caves, Douglas Point, and Middle Point to Stony Point) – licenses will not be considered for aquaculture development in this zone. Recreation and Tourism Fishing − Robe: jetty, breakwater, boat, beach and rock fishing. Major species: King George Whiting, Yellow-fin Whiting, Black Bream, Sand Flathead, Yellow-eye Mullet, Australian Salmon, Snapper, Mulloway, Sweep, Southern Rock Lobster, and Toothbrush Leatherjacket. − Nora Creina: rock, boat and beach fishing. Major species: King George Whiting, Yelloweye Mullet, Australian Salmon, Snapper, Sweep, Garfish, Southern Rock Lobster, and Toothbrush Leatherjacket. − Beachport: jetty, boat and rock fishing. Major species: King George Whiting, Black Bream, Sand Flathead, Yellow-eye Mullet, Australian Salmon, Snapper, Mulloway, Sweep, Garfish, Flounder, Southern Rock Lobster, Tommy Rough, Trevally, Toothbrush leatherjacket, and Southern Calamari. Tourism − Robe and Beachport: attract the largest numbers of visitors in the South East and as such are important tourist destinations. Main activities include recreational fishing and sightseeing. − Boatswain: swimming, boating, jetty fishing, scenic area. − Robe and Guichen Bay: sailing, boating, swimming, jetty fishing, scenic area, historic area, diving. The 10km of beach in Guichen bay is the most intensively used beach along the South East. − Nora Creina: swimming, boating, fishing, scenic area, holiday shacks. Popular area for students of marine biology as there is a great diversity of marine life. − Beachport: sailing, boating, swimming, jetty fishing, scenic area, historic area, surfing. − Sout