Download Catchment Management of the Wetlands of the Two

Wetland Conservation at Albany WA
Catchment Management
of the Wetlands
of the Two Peoples Bay Nature
Reserve
A report produced by Green Skills
for the Departments of Environment and Conservation and Land Management
and the Natural Heritage Trust Envirofund
by Wetland Project Officer Kevin Hopkinson
January 2004
1
Acknowledgments
Green Skills and the Department of Environment would like to thank the following people for
their involvement and assistance with the production of this report.
Alan Danks, Regional Leader, Nature Conservation and Sarah Comer, Ecologist from the
Department of Conservation and Land Management Albany.
Support and advice from Department of Environment staff particularly Naomi Arrowsmith
Regional Manager, South Coast Region; and Chris Gunby, Central District Manager.
Support and advice from Green Skills staff including Project Manager Basil Schur.
Field work, photography and report compilation by Kevin Hopkinson.
Do you have any comments or feedback
you would like to give?
This report is intended to generate community discussion to begin
planning activities within the Two Peoples Bay Catchment area.
If you have any comments on the recommendations provided in this report,
we would like to hear from you. Comments can be directed to:
Kevin Hopkinson
Wetland Project Officer
PO Box 525
Albany WA 6330
Ph :98410105
Fax :98421204
Email : [email protected]
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Table of Contents
1.0
Project background………………………………………………
1
2.0
Introduction to the Two Peoples Bay Wetlands…………………
2
3.0
Significance of the Two Peoples Bay Wetlands…………………
3
3.1
4.0
Regional and National Significance………
Geological history of the area……………………………………
4.1
4.0
Formation of the Two Peoples Bay Wetlands..
5.2.1
5.2.2
5.3
5.4
5.5
6.0
Physical Description……………………
Moates Suite…………………………… .
Moates Lake…………………….
Angove Lake…………………….
6
6
6
7
Gardner Suite…………………………….
Gardner Dune Suite………………………
Reef Dune Suite…………………………
8
9
9
Threats to the Wetlands of the Nature Reserve………………….
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7.0
Inundation/waterlogging…………………
Water Abstraction………
………
Eutrophication and Sedimentation………
Grazing by Livestock……………………
Feral Animals……………………………
Weeds …………………………………
Fire………………………………………
Tasmanian Blue Gum Plantations………
Spray Drift………………………………
Fencing …………………………………
Rehabilitation of fenced areas……………
Stock watering and crossings……………
Catchment Management …………………
Managing Water Levels in Gardner Creek……
Weed Control…………………………………
6
10
10
11
12
13
14
14
15
15
16
Management Recommendations ………………………………….
7.1
7.2
7.3
7.4
7.5
7.6
5
5
Significant Wetland Suites of the Two Peoples Bay Nature Reserve..
5.1
5.2
8.0
3
17
17
18
18
18
19
19
Conclusion…………………………………………………….
20
References……………………………………………………
21
3
Appendices
Appendix
1
Location maps of the Two Peoples Bay Nature Reserve
Appendix
2
Aerial images – Angove, Moates and Gardner Lakes
Appendix
3
Wetland aerial and ground photographs 2003
4
Catchment Management of the Two Peoples Bay Wetlands
1.0
Summary and Project Background
During 1998, the Water and Rivers Commission (now Department of Environment) initiated a
regional survey and evaluation of wetlands of the South Coast Region. The survey was
conducted by the V & C Semenuik Research Group and a final report was released in March,
1999.
The objectives of the report were to:
• Identify wetland regions
• Classify wetlands into consanguineous suites
(wetlands related to others by similar natural features)
• Identify wetlands of significance
• Identify significant wetlands which are at risk.
(Semenuik, 1999)
The regional survey and evaluation of wetlands is part of a broader wetland conservation
project being undertaken by the Department of Environment and community group Green
Skills.
Funding has been secured to provide on ground support for wetland fencing, revegetation and
weed control programs. The project also includes a regional wetland monitoring program and
an education component aimed at raising community awareness of the values and threats to
South Coast wetlands.
The aim of the project is to focus on catchment areas within suites of significant or
outstanding wetlands that have been identified in the survey by Semenuik (1999), and
assisting those communities to develop and implement management plans into existing
catchment activities.
The Two Peoples Bay wetland catchment area was targeted due to the significant wetlands in
the Two Peoples Bay Nature Reserve. The wetlands of the nature reserve have been identified
as being nationally significant and regionally outstanding.
This report describes the Two Peoples Bay Nature Reserve, documents the significant
wetlands of this area, and discusses management issues for the catchments of these wetlands.
For a more comprehensive summary of the Nature Reserve and Management issues, refer to
the current Two Peoples Bay Nature Reserve Management Plan 19995-2005 (CALM).
5
2.0
Introduction
The Two Peoples Bay Nature Reserve is located 35km to the east of the City of Albany on
the South Coast of Western Australia (Fig 1). The reserve covers over 4700 hectares, and
contains 5 near pristine wetland areas, including the Moates, Angove and Gardner Lakes. The
catchments of the wetlands include the Goodga/Black Cat Creek, Angove River and Boulder
Creek systems, and cover an area of approximately 12400 ha. The Angove water reserve
covers over one third of this area, and is a fully vegetated and totally protected water reserve
catchment (Fig 2).
Named in 1803 after a chance meeting by French and American mariners, Two Peoples Bay
has had a long history of whaling, sealing and fishing. During the 1930’s the area became a
popular recreation destination for local residents, with a number of holiday shacks erected.
This early development led to a small reserve being established for the purposes of Camping
and Recreation. Further interest to develop private lots in the bay prompted the Dept of Lands
and Surveys to gazetting the area as the townsite of Casuarina in March 1961. A survey of the
blocks for the area was then planned for March 1962.
During December 1961, focus on the area changed significantly with the discovery of the
Noisy Scrub-bird. This small bird had not been recorded for 72 years, with most
ornithologists considering the bird to be extinct. The rediscovery of this population triggered a
battle with the Government to protect the areas significant conservation values, involving
national and international interests, including HRH Prince Philip. The plan for Casuarina
townsite was eventually scrapped with the decision to create a reserve for the conservation of
fauna. The Two Peoples Bay Nature Reserve was finally gazetted in April 1967, with the
objective of protecting the Noisy Scrub-bird and its habitat (CALM, 1995).
The conservation values of the Nature Reserve were increased in December 1994 with the
discovery of Gilberts Potoroo, a small mammal not recorded for over 100 years. Protection of
this rare animal is also now a major management objective for the Nature Reserve.
2.1
Land Use
The Two Peoples Bay Nature Reserve is managed by the Department of Conservation and
Land Management (CALM), on behalf of the National Parks and Nature Conservation
Authority (NPNCA), primarily for the conservation of threatened fauna. Limited recreational
use is managed to ensure the protection of the nature reserves values whilst permitting public
access to small areas of the reserve.
The Angove Water Reserve adjoins the northern boundary of the nature reserve and is
protected under the state Country Areas Water Supply Act (1947) to manage potential
pollution causing activities in the area. This valuable reserve provides up to 25% of Albany’s
drinking water, and is also an important area for conservation, supporting populations of
threatened species including Noisy Scrub Bird and Western Ringtail Possum.
Much of the remaining catchments of the watercourses feeding into the nature reserve have
been cleared for agriculture. Land use ranges from cattle grazing to timber plantations.
Plantations of Maritime pine (Pinus pinaster) and more recently, Tasmanian Bluegums
(Eucalyptus globulus) cover approximately 1000 ha of the catchment.
Many of the properties in the catchment have smaller belts of bluegums planted that integrates
timber plantations into the farming enterprise, which allows them to continue traditional
farming whilst diversifying strategic parts of the farm into a long term investment in trees.
The trees also contribute significant on site benefits for stock and the landscape in terms of
shelter from wind, shade from sun, and increased subsurface water usage.
6
2.2
Report Focus
The Two Peoples Bay Nature Reserve contains a variety of wetlands that are distinguished by
a range of characteristics and attributes. Based upon an evaluation of these physical values, all
wetlands within the Nature Reserve were identified as being regionally significant in the
evaluation of wetlands of the South Coast region. This study classified the wetlands into
several suites, according to distinctive physical characteristics:
• Moates suite – Moates Lake and Angove Lake
• Gardner suite – Gardner Lake
• Gardner Dune suite – damplands, sumplands and channel wetlands in the undulating
dunal terrain between Moates Lake and Gardner Lake.
• Reef Dune suite – wetlands amongst the mobile dunes located between Moates Lake and
Sinker reef to the south (Semenuik 1999).
In addition there are a number of peat swamps and seasonally inundated areas within the
Angove Water Reserve and lower Goodga catchment in the Goodga River reserve. These
areas were not identified in the survey by Semenuik, however are within an area of the eastern
Albany hinterland to be evaluated during 2004 to add suites that may have been overlooked in
the regional wetland survey.
All wetland areas are mostly protected and buffered by the extensive Nature Reserve, so there
is limited need for direct protection from livestock by fencing, with the exception of areas
surrounding Moates, Gardner and Angove lakes (Refer Section 6.4+ 7.1.)
Management of the wetlands in the Nature Reserve will therefore depend upon catchmentrelated measures and consultation with catchment landholders. Priority works include:
•
•
•
•
•
•
Protection of waterways on private property through fencing, control of stock and feral
animals
Rehabilitation of degraded sites through revegetation with native species
Fencing of boundaries with privately owned land adjoining wetland areas that are
currently unfenced
Negotiation with landholders to acquire privately owned land and reserves adjoining the
Nature Reserve to add to the corridors extending along waterways flowing into the
wetlands
Maintenance of weed outbreaks in the Nature Reserve and catchment.
Water management issues including abstraction of water from Angove water reserve, and
opening of the sand bar at the mouth of the Gardner Creek.
3.0
Significance of the Two Peoples Bay wetlands
3.1
Regional and National Significance.
The significance of the Two Peoples Bay wetlands was recognised prior to the regional
evaluation of wetlands by Semenuik (1999), with listings in the Directory of Important
Wetlands and the Register of the National Estate recognising the area as being Nationally
significant.
The Directory of Important Wetlands in Australia was compiled in 1993 to identify important
wetland systems in Australia. The Directory lists the Moates Lake system, incorporating the
Moates, Gardner and Angove Lakes and the associated marshes, as being a ‘good example of
a system of steam fed fresh and brackish lakes impounded by coastal sands’ (ANCA 2001).
7
The Register of the National Estate has been compiled since 1976 by the Australian Heritage
Commission and lists places of natural, historic and indigenous significance. The Two
Peoples Bay Wildlife Sanctuary was registered in 1978, mainly due to the important range of
habitats within the Reserve that supports a number of threatened bird species and other
significant wildlife.
In addition to the Noisy Scrub-bird and Gilberts Potoroo, the Two Peoples Bay Nature
Reserve provides habitat for the Western Bristlebird, Western Whipbird and possibly the
Ground Parrot. This rare bird has not been recorded in the Nature Reserve in recent years,
however has populations in the nearby Waychinicup National Park. Other important species
include the Western Ringtail Possum, Carpet Python, Peregrine Falcon, Quenda, Brush
Wallaby and Red Eared Firetail.
The Angove Water reserve has been listed as an indicative place with registration pending, for
the range of ecological process the reserve supports, and the fact it is a largely undisturbed
river catchment, a feature now rare on the south coast of Western Australia.
The wetland areas within the Nature Reserve provide a range of specific habitats that are
significant for the fauna they support. Noisy Scrub-birds inhabit the fringing vegetation of the
wetland areas, and it is possible this vegetation is also suitable habitat for the Gilberts Potoroo
(Danks, pers comm).
The Australasian Bittern is another priority species found within the wetlands of the Nature
Reserve. This species is declared Threatened under the WA Wildlife Conservation Act and
has been recorded around Gardner and Moates lakes.
A survey in 1990 indicated there may be less than 100 pairs of this rare species in South West
WA, with calls being heard from 15 locations within the Nature reserve, (CALM, 1995). It is
possible that the wetland areas of the Nature Reserve may at times support close to 1% of the
total WA population of this vulnerable species.
This statistic satisfies one of the criteria for nomination to the Ramsar Convention, a
worldwide convention with over 130 parties signed to protect 1300 significant wetlands
around the world. This is further confirmed in a report to CALM (Jaensch and Watkins 1999)
nominating new sites to be added to the RAMSAR convention, citing that the numbers of
Australasian Bittern found at the Moates lake system satisfied a RAMSAR criteria. This
makes the wetlands of the area potentially significant on an International level.
The International importance of the wetlands in the Nature Reserve is further strengthened as
the wetlands also support birds that are protected on International Treaties. Moates Lake
supports 3 species and Gardner Lake 6 species that are listed on both the Japan Australia and
China Australia Migratory Bird Agreements. These agreements have been established to
ensure certain migratory species and the wetlands they visit are protected. These species are:
Moates Lake
Egretta alba - White Egret
Tringa nebularia - Greenshank
Sterna bergii - Crested Tern
Gardner Lake
Calidris ruficollis - Red-necked Stint
Egretta alba - White Egret
Pluvialis squatarola - Grey Plover
Sterna bergii - Crested Tern
Tringa nebularia - Greenshank
Tringa hypoleucos - Common Sandpiper
8
4.0
Geological history of the Area
The Two Peoples Bay area is underlain by basement rock known as the Albany Fraser
Oregon. This basement feature formed during a period of massive movements in the earths
continental plates approximately 1100 million years ago which resulted in upward intrusions
of molten granite into the more ancient bedrock material. The granite hardened to form the
large rocky outcrops of the area such as Mt Gardner and Mt Manypeaks.
Between 30 and 40 million years ago Antarctica had already broken away from Australia
causing slumping of the coastal region. This combined with a rise in sea levels rose to over
200m above the present level resulted with the intrusion of the ocean over inland areas,
bringing the coastline over 100km inland in places such as the Stirling Ranges. The large
granite mountains of the south coast region became islands in this inland sea.
During this time sediments were laid down as silt that had been washed in from the land and
marine materials settled over the new offshore areas. These tertiary sediments formed a layer
above the basement rock and are known as the Plantagenet group.
The Plantagenet sediments consist of the lower Werillup formation, formed in a swampy
environment prior to sea intrusion, and Pallinup siltstone, made up of silts washed in from the
land (forming siltstone) and sponge spicules from dead sea sponges (forming spongolite).
The Pallinup siltstone sits higher in the landscape and may overly either the Werrilup
formation or lay directly over the basement bedrock.
The development of the coastal sands that cover the Plantagenet group and form the surface
of our coastal landscape is a much more recent occurrence. Ocean levels continued to
fluctuate, dropping steadily from the ancient highs to over 100m below current levels as the
last ice age peaked, some 15000 years ago. At this time the coastline was tens of kilometres
further out, close to the present continental shelf.
Coastal sands continued to form on the migrating shoreline. Materials that make up the
coastal sands have two sources. Quartz, feldspar and silica sands are from the erosion of
bedrock that has been washed to the nearshore area. Lime sand originates from the calcareous
shells of marine animals that have been broken up by wave action. Both materials are
deposited on the shoreline, and are blown inland to form dunes and inland sand sheets.
The last rise in sea levels, around 10000 years ago saw the coastline return to near the present
level, with the formation of the current coastal dunes and inland intrusion of coastal sands.
4.1
Formation of the Two Peoples Bay Wetlands
The impermeable tertiary sediments laid down by the ancient ocean became exposed as the
seas retreated. Sands, silts and other material such as laterite have since covered these
sediments. Of significance to the Two Peoples Bay area is the major river systems that flowed
toward the coast. These systems have transported river borne (alluvial) material that has been
deposited at the lower reaches of the Goodga and Angove Rivers, which has added sediments
to the impermeable layers on the tertiary plains
During the period around 120000 years ago when sea levels where still higher than at present,
the Two Peoples Bay wetlands were linked to form an extensive estuary system. This large
body of water formed at the lower reaches of the Angove and Goodga Rivers, and may have
had a western opening to the ocean at a point on the southern coast near Rocky Point (CALM
1995).
As sediments continued to be deposited by the rivers and sea levels dropped, the estuary
system shallowed out and eventually became cut off from the ocean as coastal dunes formed.
9
The inland lake area continued to shallow out and peaty sands that fringe the lakes today are
remnants of this ancient shoreline.
Intrusion of wind blown coastal sands continued to add to the materials being deposited
around the lakes. In particular, sands were blown and settled in between Moates and Gardner
lakes, forming the extensive series of damplands including the Juniperina Creek.
The Gardner lake was the last of the wetlands to have a permanent connection to the sea, with
fossil shell beds from as recent as 4000 years ago being a relic from this period when the
system changed from estuarine inlet to a less saline lake.
5.0
Significant Wetland Suites of the Two Peoples Bay Nature Reserve
5.1
Physical Description
Wetland areas are a significant landscape component of the Two Peoples Bay Nature Reserve.
In wet years, over 20% of the Nature Reserve is either under water or waterlogged (Coy et al,
in prep). The main wetland areas are described according to the suite they have been
classified to in the regional evaluation of wetlands.
All wetlands receive inputs from both surface waters and from groundwater discharge. There
is little known about the quantity of groundwater likely to flow into the wetlands, so only the
main surface tributaries are discussed.
5.2
Moates suite – Moates Lake and Angove Lake
Semenuik (1999) describes the wetlands of the Moates suite as being large irregularly shaped
basins, formed at the mouths of long creeks that have been blocked by a dune barrier. The
wetlands are now classified as closed estuaries as they are no longer subject to estuarine
processes. This reflects on the formation history of the wetlands that have evolved to become
unique freshwater lakes with extensive areas of adjoining marsh wetlands. They are both at
different stages in their evolution and justify separate descriptions.
5.2.1
Moates Lake
This large wetland covers over 140ha and has 120ha of open water , with numerous satellite
wetlands fringing the main waterbody that contain smaller areas of open water and emergent
rushes, including a significant lagoon at the end of a small tributary that enters the Nature
Reserve and Moates Lake system from the west. At up to 5m deep, Moates Lake is believed
to be the deepest natural lake in South West WA (ANCA, 1996).
The water in Moates lake is fresh and nearly black in colour from tannin staining. The lake
supports high numbers of invertebrates, with some species collected in recent sampling being
new species not previously found (ANCA, 1996).
The shoreline of Moates Lake is dominated by the imposing Moates Lake dunes, that traverse
over 2km of the southern shoreline of the lake. This mobile dune system covers an area of
nearly two square kilometres and is steadily moving in a north easterly direction, gradually
smothering the lake shore and fringing vegetation in its path. The dune has been cut off from
the source of beach sand, and will slowly become stabilised by vegetation as the dune stops
advancing.
In addition to the fringing sedge communities, the other vegetation communities associated
with Moates Lake are low forest dominated by Wattie (Agonis juniperina) with an
understorey of Coastal Sword Sedge (Lepidosperma gladiatum), found on the western and
southern shoreline, and woodland which dominates the northern and western shoreline.
Common woodland species include Wattie, Peppermint (A.flexuosa), Yate (Eucalyptus
cornuta), Bullich (E.megacarpa), with understory of Swamp Banksia (Banksia littoralis).
10
The Goodga River is the main tributary flowing into Moates Lake, originating 7km to the
north in the Angove water Reserve. The main channel branches and flows through 10km of
cleared farmland, before entering the Goodga River Reserve, a 300ha ‘A’ class reserve. The
addition of this and other areas to the Nature Reserve is an objective of the current Two
Peoples Bay Nature Reserve Management Plan (1999-2005). Other tributaries include the
Black Cat Creek to the north, and two smaller creeks that flow in from the west.
The Goodga River is an important waterway supporting two rare fish species. It is the only
waterway in WA where the Trout minnow (Galaxias truttaceus) is found, with Moates Lake
being an important nursery area for larval Trout Minnows, most likely because of the high
numbers of invertebrates that are found there (Morgan, 2002).
The Balston’s Pygmy Perch (Nannatherina balstoni) has a restricted distribution in WA, and
the Goodga River is the eastern most waterway this fish species is found.
Recently a fish ladder has been constructed next to a weir on the Goodga River, to assist
Trout Minnows and other native fish to migrate upstream to areas of the river that were
previously inaccessible since the construction of the weir. Recent monitoring of the use of the
fish ladder is encouraging, with over 1700 Trout Minnows counted traversing the structure
over a four day period (Morgan, pers comm).
5.2.1
Angove Lake
In contrast to Moates Lake, Angove is much shallower and covered in extensive beds of
emergent rushes, mainly Jointed Twig Rush (Baumea articulata). The patchy areas of open
water are broken up with dense stands of this plant, which gives way to other sedge species
towards the shallower lake margins. The main waterbody of the lake covers around 40ha,
however the total area covered by the lake and the surrounding wetland areas is over 100ha.
Angove Lake and part of the Angove River that flows into the lake are contained within an
isolated section of the Two Peoples Bay Nature Reserve. This section is separated from the
main body of the Nature Reserve by a large area of intact wetland vegetation and a small
corridor of cleared farmland.
This cleared area was once a southern extension of the Angove Lake fringe that linked the
wetland to the nearby Gardner Creek. This area was subsequently drained with a 3km channel
constructed to drain the farmland that was cleared between the two reserve areas, and has
remained part of the privately owned property that fringes the Angove Lake. A management
priority is to work towards adding this section to the Nature Reserve to make the Reserve
boundary continuos and increase the corridor potential of this area.
The water in Angove Lake is also fresh, however is clear and lacks the tannin staining found
in Moates Lake(Coy et al in prep). The lake is fed by the Angove River, that flows from the
Angove Water Reserve to the north west, and from the smaller Boulder Creek, that flows in
from the west.
The hydrology of the Angove Lake system has been considerably interrupted with the
combination of water abstraction from the Angove River upstream and the drainage of the
wetland areas downstream of the Lake. Care has been taken in determining sustainable
ecological water requirements for the river and wetland, to ensure that the flows from the
river feeding the lake are not disrupted by water abstraction to the detriment of the wetland
and the flora and fauna communities it supports (Davies et al, 2001).
11
The Angove drain adds considerably to the levels of the Gardner Creek. This system backs up
and floods prior to the breaching of the sand bar at the creek mouth. It is possible that high
water levels in this creek have been responsible for flooding of Noisy Scrub Bird habitat
around Gardner Lake during extremely wet years. Management of the sand bar at the mouth
of this creek is therefore a priority activity that involves balancing the water levels in the
Angove drain with the creek levels and the amount of the surrounding wetland areas that are
flooded. Refer to discussion in section 6.1 for further information.
5.3
Gardner suite – Gardner Lake
Gardner Lake is described as macroscale and rounded- a large circular open waterbody
covering over 180ha, with a total wetland area increasing to 350ha during winter when
adjoining sedgelands are flooded. It is also classified as a closed estuary system, due to the
formation history, however is still periodically connected to the ocean by the Gardner Creek.
The lake has formed on a broad plain of alluvial material and is underlain by sands and
muddy silts. At 1.5m above sea level the lake sits lower in the landscape than the other lakes.
Inflow to the lake is mainly from the Moates Lake via the Juniperina creek, and from small
seasonal watercourses that drain from the surrounding reserve. There is also an occasional
intrusion of seawater during high tides when the Gardner creek is open to the ocean, before
the sand bar at the creek mouth closes over.
This lake was probably the last of the wetlands to be influenced by estuarine processes,
evidenced by the presence of fossil shell beds in the basin sediments. These are between 4000
and 6000 years old, and mark the transition of a saline to fresher system as the connection to
the ocean was blocked up (CALM 1995).
The water in Gardner Lake is clear and ranges from fresh to brackish. During summer, as
water levels recede and salinity levels increase, broad flats are exposed around the fringes of
the lake which become perfect feeding grounds for migratory wading birds. Gardner Lake
supports the greatest variety and highest number of birds, with 36 of the 44 wetland species
found in the Nature Reserve recorded from this lake.
Fringing rushes dominate the shoreline, particularly the eastern shore where stands of rushes
extend up to 100m into the lake when full. Fringing vegetation consists mainly of species able
to tolerate seasonal inundation or waterlogging, such as Saw sedge Gahnia trifida, Sword
sedge Lepidosperma gladiatum, Wattie and various smaller shrubs.
The Gardner Creek is around 3km long and links Gardner Lake with the ocean at the Two
Peoples Bay beach. The creek leaves the eastern shore of the lake and winds through the
fringing sedgelands at then through a low paperbark forest, consisting of tall paperbarks
Melaleuca cuticularis, M.raphiophylla and M.preissiana with little or no understorey.
The lower reaches of the Gardner Creek flows through a break in the coastal dunes. The creek
is associated with a series of coastal sumps and damplands that have formed as high winter
watertables are expressed between the beach and the granite hills at the southern end of the
beach. The location of the creek mouth has changed over time, in the past the creek would
have linked with the wetlands near the present day visitors centre, however in recent times the
sandbar at the creek mouth has been mechanically breached at a location to the north of these
wetlands.
The breaching of the sand bar is timed to prevent water levels in the creek rising to a depth
that would flood the bridge that crosses the creek and provides vehicle access into the Nature
Reserve. Flooding of the road bridge however is not the only problem related to high creek
levels. Heavy rainfall during 1988 resulted in flooding of the fringing margins of the Gardner
Lake which has possibly resulted in the loss of feeding zones for the Noisy Scrub bird
(CALM 1995). Manipulation of creek levels is recognised as a potential solution to this
problem. The Angove drain also backs up in times of high creek water levels, causing
problems with flooding in the adjacent farmland.
12
Breaching of the bar and releasing high water levels from the Gardner creek may therefore
prevent flooding of the access road, important Noisy Scrub bird habitat and adjacent farmland
and so is a community management issue that needs input and consultation with a range of
stakeholders. This consultation and cooperation is therefore a management priority for the
Nature Reserve.
5.4
Gardner Dune suite
This group of wetlands have formed in the undulating dune terrain located between Moates
and Gardner Lakes. The wetlands consist of a series of damplands, sumplands and a
meandering seasonal channel known as the Juniperina Creek.
With up to 6m difference in surface levels between Moates and Gardner Lakes, there is
potential for considerable sub surface flow through the sand sheet and dunes that has settled
between these two lakes. During higher water levels in winter, this flow is expressed on the
surface of the low lying areas between dunal highs and in particular, evident in the channel of
the Juniperina Creek.
The dominant overstorey fringing vegetation of the creek is a tall stand of Wattie, Agonis
juniperina. A fire during the summer of 2001 killed this impressive stand of trees, that were
over 15m tall and dominated the undulating sandy landscape. This 30-year-old stand of trees
had regenerated after another wildfire in the 1970’s killed the existing vegetation. The fire
cycle now continues as the next generation of these trees regenerate.
This cycle of loss of adult trees with each fire highlights the importance of fire management
in the Nature Reserve.
5.5
Reef Dune suite
The wetlands of the Reef Dune suite are small irregularly shaped damplands and sumps that
have formed in the hollows amongst the mobile dunes located between Moates Lake and
Sinker reef to the south (Semenuik 1999).
These wetlands are a reflection of a perched watertable that forms as rain percolates through
the dunes and sits above the impermeable sediments underlying the dunes, expressing on the
surface in depressions between dunal highs.
Most of these tiny wetlands are un-vegetated ephemeral damplands, which may become
covered as the sands of this dune system continue to mobilise. Some will then become
colonised with vegetation as the sand stabilises over these winter wet areas.
13
6.0
Threats to the Wetlands of the Two Peoples Bay Nature Reserve
Wetlands and waterways in southern Western Australia are under threat from changing water
quality and quantity and degradation of fringing vegetation. Changes to water quality and
quantity have occurred through increasing salinity, eutrophication and sedimentation. These
changes are directly attributable to catchment clearing (Schofield, 1989).
Changes in the quantity of water entering a wetland can alter wetland hydrology and change
the ecology of the wetland, particularly within the transitional areas fringing the wetland.
Removal of native vegetation through clearing results in changes to the groundwater regime,
with less groundwater being utilised through deep rooted vegetation, and more surface runoff
to discharge into waterways. This increase in catchment water damages wetland vegetation
through waterlogging and inundation.
Rising groundwater and associated waterlogging and salinisation, combined with grazing by
introduced animals, is responsible for much of the decline in vegetation seen in wetlands and
waterways across southern Western Australia (Olsen & Skitmore, 1991).
Reduction in the amount of water flowing into a wetland will also affect wetland hydrology
and health. Water abstraction for domestic consumption or increased catchment water use
from tree plantations can reduce the quantity of water available to the wetland ecosystems and
therefore affect the wetland ecology.
Catchment issues relating to water quality and quantity are the main processes that potentially
threaten the wetlands of the Two Peoples Bay Nature Reserve.
6.1
Inundation/waterlogging
Inundation of wetland margins from excess catchment water is unlikely to be a future threat to
the Two Peoples Bay wetlands. Much of the catchment external to the Nature Reserve is
vegetated, with minimal disruption to the hydrology in terms of excess water. In particular,
the catchment of one main tributary, the Angove River, is almost pristine and fully vegetated,
with the exception of the uppermost 5% which is cleared (Davies et al, 2001).
The Goodga River is the other major tributary, and whilst this catchment has been largely
cleared for agriculture, the establishment of timber plantations on cleared farmland in recent
years has added to the vegetated reserves retained in the catchment. This means that today
less than 60% of the catchment remains cleared for agriculture, with high water using timber
plantations helping to restore the hydrology.
In addition, the wetlands of the Nature Reserve are buffered by potential problems resulting
from excess water because they are interlinked and still have a seasonal outlet to the ocean.
The sands that fill the landscape between Moates and Gardner Lakes provide a transmissive
medium for water to move and so readily drain excess water from Moates lake, and the
constructed drain at Angove lake ensures this area too has an outlet for excess water.
The management of the Gardner Creek is the major factor that influences the extent of
waterlogging in the wetland areas of the Nature Reserve, in particular around Gardner and
Angove Lakes.
The seasonal opening of this system into the ocean to prevent winter flood waters from
backing up is essential to prevent waterlogging of the cleared farmland surrounding the
Angove Lake margins.
14
The drain does however interrupt the natural hydrology that the Angove system has evolved
with, potentially reducing the wetting cycle by removing water quicker than would have
occurred by natural sheet flow. The impact of this may be reduced slightly, however, as the
drain has a culvert at a crossing point that sits above the base of the channel, so low flows that
don’t reach the depth of the culvert are effectively dammed and back up in the drain (Davies
et al2001). This culvert also prevents the intrusion of saline back flow water up the drain
when the Gardner Creek is open to the sea during times of high tides.
The natural state for the Gardner Creek would be to only breach the sandbar during wet
winters, so historically there would always be seasons when the creek backed up and stayed
full, unable to break through the sandbar at the mouth. The lakes would therefore have a
natural cycle where flooding of the fringing margins was more extensive and prolonged in
years when the creek did not open.
At present the main objective for opening the sand bar and lowering the creek levels is to
prevent the flooding of the road into the Nature Reserve. Research is required into the
hydrology of the drainage system and the relationship with the ecology of the wetlands, to
determine, for instance, if there is a significant impact on Noisy Scrub bird habitat due to
waterlogging from high creek levels.
The Two Peoples Bay Nature Reserve Management Plan cites a study into the hydrology of
the Gardner Lake catchment to determine the relationships between the catchment, river flows
and flooding of Noisy Scrub Bird habitat as a Research strategy under the Research and
Monitoring objectives (CALM 1995).
6.2
Water Abstraction
In contrast to the potential problems that exist from excess catchment water, there may also be
threats to the wetlands from reductions in available catchment water. This is due in particular
to the abstraction of water from the Angove River. Presently the Water Corporation is
permitted to abstract 1600ML of water per year from the Angove River, which is estimated to
be around 60% of the mean annual flow of the river.
During 2001 the Water Corporation submitted a proposal to increase abstraction levels to
1800ML/annum and increasing to 2200ML/annum in wet years, potentially removing 67-82%
of mean annual flow of the river. A study of the Environmental Water Requirements (EWR)
of the Angove River (Davies et al, 2001) was commissioned to determine the levels needed to
sustain the water dependant ecosystems.
This study determined that there were minimum monthly flow levels required by the river,
mainly to sustain the native fish species found in the Angove River. Certain levels were
needed to ensure suitable flow over rocky riffles to enable macroinvertebrates to survive, an
important food source for the fish. Another consideration was the maintenance of high water
levels during winter, to enable certain fish species to lay eggs on submerged fringing
vegetation.
No reference was made in the study to possible effects on the wetlands and smaller tributaries
in the upper Angove River catchment, so it is difficult to comment on the relationship
between these feeder systems and the main channel.
The requirements of Angove Lake were also unknown, largely due to the lack of hydrological
information relating to groundwater inputs into the system. However, given that the
considerable base flow into the Angove River is from groundwater, it is suspected that this
lake receives also receives groundwater discharge from an area of over 6km to the west of the
lake.
In recognition of this fact, the EWR calculated for the Angove River to maintain the levels in
the Angove Lake was set so as to balance the expected loss from the lake due to evaporation,
which would obviously be higher during summer months. This would ensure the unknown
quantity entering the lake from groundwater would not be interfered with.
15
The next step is for the Department of Environment to set an Environmental Water Provision
(EWP) for the system, to safeguard the Angove River by permitting abstraction that protects
the minimum requirements of the river based upon the levels determined in the EWR.
6.3
Eutrophication and sedimentation
Clearing of catchments for agriculture has meant rainfall runs off the land surface and into
waterways more rapidly. The increase in catchment runoff , together with loss of fringing
waterway vegetation, has resulted in the transport of dissolved nutrients and rich sediments
from the agricultural catchments into the waterways and wetlands.
Fringing vegetation is valuable to help filter nutrient laden run off before entering a
waterway. The fringing sedges, rushes, grasses, trees and shrubs slow and block the flow of
run off, allowing sediments to settle out. Dissolved nutrients can be intercepted and utilised
by these plants which also help clean up run off water.
Fringing sedges and rushes uptake large amounts of nutrients and act as nutrient sinks, storing
more nutrients than they use. (Taman, 2001). They also have bio-films of biologically active
mucous that surround the plant stems and readily uptakes nutrients from water that comes into
contact with the film, so adding to the filtering capacity of the plants.
Nutrients that threaten water quality include phosphorous and nitrogen, which may be found
in various forms. Inorganic or dissolved phosphorous is adsorbed by soil particles and is
readily transported with mobilised sediment (George et al 1996).
Inorganic or dissolved nitrogen occurs as ammonium, nitrate and nitrite. Ammonium adsorbs
to soil particles, but is slowly oxidised to nitrite. Both nitrate and nitrite are highly soluble and
easily transported by water (George et al 1996).
Water quality parameters such as salinity, nutrient levels and pH and depth levels in Moates
Lake have been monitored by CALM as part of the South West wetlands monitoring program
since 1984. In addition, the Water and Rivers Commission/Dept of Environment have been
recording nutrient levels from Goodga Creek since 1996. The range of levels for Total
Nitrogen (TN ) and Total Phosphorous (TP) and for the period 1995 to date are shown below.
Moates Lake
Date
TP mg/L TN mg/L
13/09/1995
0.02
0.97
10/11/1995
0.03
17/09/1996
0.03
06/11/1996
0.02
18/09/1997
0.04
06/11/1997
0.03
17/09/1998
12/11/1998
16/09/1999
0.05
11/11/1999
0.09
04/05/2000
13/09/2000
0.03
0.93
05/11/2000
0.04
11/09/2001
0.03
08/11/2001
0.03
1
16/09/2002
0.02
0.72
05/11/2002
0.02
0.53
Average
0.03mg/L 0.68mg/L
EPA level < 0.05 mg/L <0.5 mg/L
Goodga River
TP mg/L TN mg/L
0.12
0.75
0.23
2.1
0.11
1.1
0.06
0.07
0.68
0.76
<0.1mg/L <0.75 mg/L
Table 1-Nutrient Levels for Moates Lake (Dept CALM 2003) and Goodga River (Dept Env 2003)
16
The Environmental Protection Authority (EPA) have developed environmental water quality
guidelines for standing and flowing fresh water (George etal,1996), to determine acceptable
nutrient levels that would not significantly disrupt normal ecological systems. From the table
of data presented above, it would appear that the levels of phosphorous are generally within
the acceptable limits (ie below 0.05mg/L), however there are elevated levels of total nitrogen
present in Moates Lake, with all readings measured being over the acceptable limit of 0.5
mg/l.
Levels of TN and TP are generally higher for the Goodga River, indicating there may be some
nutrient uptake/settling, in particular of phosphorous, as the water flowing from the river
dissipates through the system of wetlands fringing Moates lake.
Whilst these levels are elevated they are still in the moderate range and not likely to be a risk
to the health of Moates Lake. In particular, the dark colour of the water in Moates Lake will
serve to buffer these levels. This colouration is from tannins that leach into the water from the
breakdown of organic material such as leaves (Pen 1999). The dark colour reduces the
amount of light that can enter the water which inhibits the growth of aquatic plants and in
particular restricts blooms of algae.
Future monitoring of the water quality in both Moates Lake and Goodga River will be useful
if there are any further waterway protection works implemented in the catchment. It is hoped
there would be a reduction in the levels of nutrients found in these waterways, however the
input due to groundwater is still an unknown factor.
In addition to nutrients washing into waterways, sediments can also be a problem. Sediment
build up in wetlands can physically threaten wetland function. As wetland basins fill with
sediment they become shallower and so flood further and further outwards, effectively
drowning fringing vegetation.
Sediment transport in the small catchments of the Two Peoples Bay wetlands is however
relatively minor as the gradients of defined water courses are low, and the material moves in
sheet water flow over mainly grassed and pastured paddocks. Sediment control and associated
nutrient reduction can still be assisted by protecting and enhancing fringing vegetation that
buffers the waterways and wetlands.
6.4
Grazing by livestock
This is a major threat to many wetlands, waterways and areas of remnant vegetation
throughout Australia. Livestock can damage native vegetation and waterways in a number of
ways:
• Direct grazing on vegetation, killing existing plants and preventing new seedlings
establishing
• Ringbarking trees by scratching against bark
• Trampling small plants, compaction of ground around trees which can damage roots, and
pugging up wet ground leading to erosion
• Dropping of faeces that can import of weed seeds, also adds nutrients to runoff water.
• Destabilising banks of waterways and wetlands through direct trampling and removal of
protective vegetation leading to erosion and downstream sedimentation.
Fortunately stock access is limited to only small areas of the waterways and wetlands of the
Two Peoples Bay Nature Reserve. Most of the areas surrounding the major lakes are
contained within the protected areas of the nature Reserve, providing a dense wide protective
buffer of vegetation around these important wetlands.
17
There are, however, some areas that stock can access that threaten the fragile fringing and
upland vegetation communities that buffer the wetlands. These are:
•
•
•
The Eastern shore of Moates Lake, adjoining with the western boundary with location
3777. A strip up to 200m wide on the western boundary of this privately owned location
is uncleared and contains Noisy Scrub Bird habitat and would make a valuable addition to
the upland buffer fringing the Moates Lake (CALM 1995).
The entire boundary of Angove Lake, which is contained within location 3777. In
particular, the western and eastern shoreline of Angove Lake is poorly fenced and may
allow stock access.
The northern side of Gardner Lake. The boundary with private property is fenced,
however the fence is in poor condition and may permit stock access.
In addition, there are sections of the Goodga River that remain unfenced, placing the
remaining fringing vegetation and riverbanks of these areas under pressure.
Fencing of all these unprotected areas is a priority activity to ensure protection of the
wetlands and waterways. It is however unrealistic to expect landholders to complete this
important work on their own without some form of assistance.
Given the importance of completing this works, it is essential that a catchment based scheme
of funding and perhaps labour assistance be offered to landholders., refer to Section 7 for
discussion and management recommendations.
6.5
Feral Animals
Animals such as foxes, feral dogs and cats and black rats have been found in the Nature
Reserve and are known to prey on native mammals, birds and reptiles. The high conservation
values of the Two Peoples Bay Nature Reserve have ensured that an active feral animal
control program is in place. Foxes, in particular, have been the target of a long term baiting
control program. (CALM 1995). Western Shield targets over five million hectares across
Western Australia annually, to make it the biggest wildlife recovery program undertaken
anywhere in the world.
Other pests found in the Nature Reserve include rabbits and feral bees. Rabbits can cause
disturbance through digging warrens and grazing on native vegetation, particularly young
seedlings. This can impinge on the ability of vegetation to regenerate after flooding or fire,
and places native fauna under stress through added competition for food. The grazing and
diggings of rabbits can instigate erosion on fragile sandy areas. Rabbit control is therefore
essential in these remnant areas to prevent population explosions that could devastate the area.
6.6
Weeds
Weeds can threaten the habitat value of a wetland by out competing native vegetation,
affecting nutrient recycling, increasing fire risk, and inhibiting regeneration of natives,
particularly after a disturbance such as fire or stock grazing. Dense outbreaks of weeds
including Taylorina (Psoralea pinnata) and inkweed (Phytolacca octandra) have been
recently observed colonising wetland fringes around Angove Lake burnt during the fire of
2001.
Other weed outbreaks include woody weeds such as Sydney Wattle (Acacia longifoila) and
Victorian teatree (Leptospermum laevegatum) in areas such as around the pumping stations on
the Angove River, and a dense stand of Bullrush (Typha orientalis) that is choking sections of
the Goodga River. Physical removal of such weeds and ongoing maintenance is a priority to
ensure these infestations do not get out of control.
For waterways in cleared agricultural catchments, fencing to exclude stock is an effective way
of reducing weed invasion. Sheep and cattle can transport weed seeds, denude native
18
vegetation, and provide disturbed environments ideal for the establishment of fast growing
weeds (Hussey et al, 1997).
Weed management is a common concern to landholders following the fencing of wetlands
and waterways, as these colonising plants overrun native plants once they are no longer under
pressure from stock, and create potential fire risks. In cases where treatment such as chemical
over-spraying is not possible or desired, an appropriate management technique would be to
permit the controlled grazing of livestock in fenced off areas on private property for short
periods to allow stock to graze weeds down before they are able to set seed. This is a
particularly effective method for controlling rampant grasses like kikuyu.
6.7
Fire
Fire management is a high priority for the Nature Reserve. The high conservation values of
the reserve are made more significant because some areas have remained unburnt for over
50years. This long fire free period creates dense areas of undergrowth, creating ideal habitat
for endangered species such as Gilberts Potoroo and Noisy Scrub bird.
Retention of such fuel rich areas create a high risk should a wildfire sweep through the area,
so the CALM management of the reserve must tackle both fuel reduction and fire
suppression.
Management strategies include creation of a wide low fuel buffer to separate the long unburnt
areas around Mt Gardner, the initial discovery sites of both the Gilberts Potoroo and Noisy
Scrub bird, with other areas of the reserve.
Deep peat soils found in sedgelands surrounding the wetland areas of the Nature Reserve
create another fire risk, with these deep organic soil profiles being difficult to extinguish once
alight.
Fire risk is reduced by the use of gas barbecues in recreational areas, and the risk from
recreational activities is further managed by the closure of the nature reserve to the general
public during periods of extreme fire danger. The risk of wildfire from lightening strike
during summer electrical storms is ever present, though only 3 fires in the past 20years have
started from this cause (CALM 1995). The most recent of these was the wildfire that started
from a lightning strike in the Angove Water reserve during the summer of 2000.
Ideally specific fire management objectives for wetlands would be determined and included in
future fire management planning within the Nature Reserve.
6.8
Tasmanian Blue gum plantations
An interesting scenario in the catchment water balance occurs as a result of the significant
proportion of the landscape that has been planted to Tasmanian blue gums. These fast
growing eucalypts utilise large amounts of fresh water from the soil profile and may impact
hydrologically on the catchment of the wetlands, in particular Moates Lake.
Research conducted on blue gum water use confirms that tree roots may be able to access the
watertable up to 20m deep (Ferdowsian/Crossing 2000).
However the same authors believe the trees may only be a threat when they are planted closer
than 500m to a wetland or waterway.
In the Goodga River catchment, the plantation trees may reduce recharge in the landscape,
stabilising groundwater levels and creating a hydrology closer to the pre-clearing condition.
There should however be adequate buffer of unplanted area between waterways and
plantation to ensure sufficient rainfall runoff occurs to maintain seasonal water levels. The net
result should be closer to natural water regime than has occurred since clearing (Ferdowsian
pers comm).
6.9
Spray Drift
19
An issue that has been on the public agenda recently is spray drift from plantations being
aerial sprayed with insecticides. A protocol developed by the Plantation Forest industry deals
with issues directly related to aerial application of pesticides.
Sprays commonly used for this purpose include Dimethoate, which is known to be extremely
toxic to aquatic fauna, particularly aquatic fauna and macroinvertebrates like gilgies and
marron.
The protocol has been developed as an agreement that can be signed off by all parties and
carries no legal implications. It is also somewhat lacking in that ‘sensitive properties’ are only
those that are affected on a commercial basis.
Watercourses and wetlands are not considered as part of the current protocol.
A new code of practice for all agricultural spraying has been developed and included in the
current draft of the Agriculture Management Bill. It is therefore important to liase with the
plantation companies and ensure they are aware of waterways and significant wetland sites
that require protection.
Importantly, some plantation companies are now recognising that in certain situations
spraying is not cost effective, with predation by natural predators being seen as nearly as
effective for pest control. For this reason, some timber companies are scaling back their
spraying programs and opting to rely upon biological control when infestations of damaging
beetles are not severe. (ITC, 2004).
20
7.0
Management Recommendations
Management of the Two Peoples Bay wetlandsis essentially covered by the Department of
CALM Management Plan covering the Two Peoples Bay Nature Reserve. Numerous sections
of this plan have been quoted during this report, detailing management measures that are
already recognised as being necessary to help preserve the conservation values of the
wetlands.
Most of these issues concern the wetlands and vegetation areas contained within the Nature
Reserve and relate to vegetation and habitat management through control of fire, feral
animals, and human access.
There is also a range of management strategies that relate to the waterways and catchment
area that surround the Nature Reserve and are outside of the scope of the Nature Reserve
Management Plan, and these are discussed below in more detail.
7.1
Fencing of waterways and wetlands to protect fringing vegetation from stock
access.
Whilst a catchment survey has not been completed to determine the amount of fencing
required, it is obvious from interpretation from aerial photographs that some sections of the
tributaries entering the Nature Reserve remain unfenced and poorly vegetated. Protection of
these riparian areas is a priority to protect the remaining vegetation where it is present, and to
rehabilitate areas where fringing vegetation has been damaged.
Fencing is an expensive and time-consuming job that is difficult for landholders to give a high
priority to. It is essential farmers are offered help to pay for the cost of the fencing materials,
and provided labour assistance to erect the fence.
It is recognised that standard landcare grants for fencing of $600 per km is often only one half
to one quarter the cost of a fence or even less for winding waterways requiring many strainer
assemblies. Often this is not sufficient a grant to entice farmers to make the commitment to
fence areas such as remnant vegetation and waterways. Whilst higher rates up to the total cost
of materials are obtainable, they require covenants to be placed on the property which is often
viewed by landholders as restrictive and intrusive.
There are, however, funding programs available to farmers that can cover the entire cost of
fencing materials, without any onerous restrictions such as covenants or caveats. Important
and high priority areas such as the Two Peoples Bay catchment can target special funding
programs such as that offered by the Gordon Reid Foundations’ priority program funded
through Lotterywest, to receive funding that can pay for the whole amount of fence costs.
In particular, there are property boundaries where privately owned blocks border the Nature
Reserve, where fencing is not present or is inadequate to exclude stock, such as those
discussed bordering parts of Moates and Angove Lakes. It is imperative these areas are
targeted as part of the fencing program, to enable the cost of materials to be subsidised to
ensure this vital protective fencing is erected.
Assistance with labour is also available through Green Corps programs with currently up to 3
teams every 6 months being operated in Albany. These programs, managed by Green Skills
and Job Futures, can provide at no cost to the landholders, a team of up to 10 trainees, with an
accredited and experienced supervisor. The teams are fully covered by insurance, so there is
also no liability risk for the farmers.
21
Strategies
• Contact all landholders in the catchment and gauge interest to fence waterways by
offering funding to pay for the cost of all fencing materials required.
• Complete catchment fencing assessment, detailing areas requiring fencing
• Compile an application form from interested landholders and submit to relevant
funding scheme.
• Offer labour assistance to landholders to complete fencing, utilising landcare trainees
participating in Green Corps training teams. Apply to Green Skills to book a team once
scale of project is determined.
7.2
Rehabilitation of fenced areas
Planting of native seedlings in some areas to be fenced will help replace vegetation lost
through years of grazing by stock. Important weed control and site preparation can be
completed prior to fencing and should be planned as the fencing project becomes
implemented. Once again, assistance is available to pay for native seedlings and complete the
planting, with only limited input required from landholders to help spray and prepare the site.
Strategies
• Include revegetation component into prospective fencing projects
• Apply for funds to cover costs of seedlings and limited site establishment
• Apply for assistance to plant through Green Corps
7.3
Stock watering and crossings
An important consideration when removing stock access from waterways is the provision of
alternative watering points when stock may have relied on access to the creek for drinking.
Options include corralled points on creeks with gravel bases to deter stock camping for long
periods, pumping to troughs or digging new soaks.
There may also be a requirement to have access across the waterway, not only for stock but
for landholders with machinery. Stabilised crossing points are an easy option and range from
being a simple gravelled crossing, to more complex culverts and bridge type crossings,
depending upon the channel depth and flow characteristics.
Funding can also be extended to help with the cost of drinking points and crossings, and this
should be a component of the fencing/revegetation program.
7.4
Catchment Management
Following the planning of the streamlining works proposed above, a final step to ensure the
sites are well managed is to form a catchment group to plan activities and coordinate requests
for assistance.
This process should ideally occur prior to the application for funds and completion of works,
however it is recognised it may be necessary to get some ‘runs on the board’ before
landholders in the area are interested in committing to forming as a group to plan future
management issues.
It is recommended that a Two Peoples Bay Catchment Group be established, comprising the
representatives from the following:
•
•
•
•
•
•
Landholders in the catchment and surrounding area, including plantation managers
Department of CALM staff
Other agencies such as Departments of Environment and Agriculture
Water Corporation
Local catchment support officer, from Eastern hinterland or adjoining areas such as
Oyster Harbour
Other community organisations such as the Albany Community Environment Centre.
22
This group would have the charter to formally meet at set periods, and discuss and plan out
management issues that arise from the catchment and adjoining areas to the Two Peoples Bay
Nature Reserve. Ongoing issues such as weed and fire management can be thrashed out by all
parties that have a stake, and logistical matters such as accessing resources can be planned
more effectively.
7.5
Managing Water Levels in Gardner Creek
The breaching of the sand bar at the mouth of Gardner Creek is another important
management activity that impacts a range of community stakeholders, including adjoining
landholders.
Currently the decision to open the bar is made at the discretion of staff from the Dept of
CALM, mainly to prevent the flooding of the Nature Reserve access road. As has been
discussed, however, there are some other important considerations including flooding of
important habitat areas and adjoining farmland.
The future management of the levels in Gardner Creek could therefore also become part of
the responsibility of the Catchment Group, or at least input could be sought from
representatives from this group prior to opening.
7.6
Weed Control
The presence of a range of terrestrial and aquatic weeds in the waterways and remnant
vegetation of the catchment and Nature Reserve makes weed control an important
management issue that will need regular action to ensure that outbreaks do not become out of
control.
Of particular concern is the presence of Typha in sections of the Goodga River. This weed has
potential to alter the dynamics of reaches of the creek by choking the channel and altering
flow regimes. A concerted effort will be required to remove plants from the infected areas,
with the need for an on going program of action to monitor future growths.
At present Green Skills in Albany has time allocated with Green Corps teams to begin liasing
with CALM staff and start working on this problem. Hopefully there will start to the removal
during the summer of 2003/2004.
23
8.0
Conclusion
This report has brought together information about the Two Peoples Bay Nature Reserve
wetlands that will help to raise local awareness to the value and significance of these unique
wetlands and aid in the future management of these sites.
Significant works have already been undertaken by landholders in the catchment towards
fencing and rehabilitating the waterways of the Goodga River.
The next important step is to approach farmers in the area and seek support for those
interested in fencing and rehabilitating areas of creek, wetland and remnant vegetation.
The Two Peoples Bay Catchment falls into the work areas of two Community Landcare
Coordinators (CLC’s), with the Angove River being in the Eastern Hinterland covered by
Bella Bamford at Wellstead, and the Goodga system being in the Oyster Harbour Catchment
covered by Shannon McKenzie at Mt Barker
It is strongly recommended that the local CLC’s be approached to coordinate and facilitate a
wetland catchment working group, involving agencies including Department of Conservation
and Land Management and Department of Environment, Water Corporation and Department
of Agriculture, and perhaps most importantly, representatives of local landholders.
This working group can then meet to discuss issues relating to landholder needs and priorities
for the Nature Reserve, and coordinate applications for funding opportunities that will assist
the community to complete priority works.
The formation of such a group will enable a better working relationship to be established
between CALM and other agencies and landholders in the area, and ensure the water quality
and vegetation of the wetlands and waterways of the Two Peoples Bay Nature Reserve are
protected well into the future.
24
References
Coy NJ, Halse SA, Storey, AW (in prep) Aquatic Ecosystems in The Natural History
of Two Peoples Bay Nature Reserve (Hopkins, AJM and Smith GT eds), Research
Bulletin, Department of Conservation and Land Management, Perth.
Danks, A 2003 Personal communication, Department of Conservation and Land
management, Albany Western Australia.
Davies PM, Creagh S, Storey AW 2001 “Environmental Water Requirements of
Angove Creek & Limeburners Creek” Water Corporation of WA Report 10/2001
Department of Conservation and Land Management 1995 “Two Peoples Bay Nature
Reserve Management Plan 1995-2005” for the National Parks and Nature
Conservation Authority Perth, Western Australia.
Environmental Protection Authority 1993
Western Australian Water Quality
Guidelines for Fresh and Marine Waters, EPA Bulletin 711 (draft).
Ferdowsian, R. 2000 Personal Communication, Agriculture Western Australia, 444
Albany Highway Albany, WA 6330.
Freeman MJ, 2000 “The Geology and Interpretive Geology, Two Peoples Bay Nature
Reserve District Western Australia”, Department of Minerals and Energy Western
Australia, Land Access Branch, Report EV 171, in prep.
George,R. Weaver D, Terry J, 1996 “Environmental Water Quality – A Guide to
Sampling and Measurement” Agriculture Western Australia, Miscellaneous
publication 16/96 Issn 1326-4168.
Hussey,B.M.J. Keighery,G.J. Cousins,R.D. Dodd,J. Lloyd,S.G. 1997 “ Western
Weeds: A guide to the weeds of Western Australia”, The Plant Protection Society of
Western Australia (Inc.), Victoria Park, WA, 6100.
Jaensch, RP 1992 “Moates Lake System-WA050” in Directory of Important
Wetlands, Department of Environment and Heritage, Commonwealth Government of
Australia.
Jaensch, RP. Watkins, D 1999 “Nomination of Additional RAMSAR sites in
Western Australia”, Report to Department of Conservation and Land Management,
Perth Western Australia.
Lane, JAK 2003, Wetland Monitoring Data, Department of Conservation and Land
Management, State of Western Australia.
Morgan, DL 2003 “Distribution and biology of Galaxias truttaceus (Galixidae) in
south-western Australia, including first evidence of parasitism of fishes in Western
Australia by Ligula intestinalis (Cestoda)”, Environmental Biology of Fishes 66 155167, Kluwer Academic Publishers, Netherlands.
Olsen, G & Skitmore, E. 1991 “State of the Rivers of the South West Drainage
Division”, Western Australian Water Resources Council Publication No 2/91
25
Pen, L. 1997 “A Systematic Overview of Environmental Values of the Wetlands,
Rivers and Estuaries of the Busselton – Walpole Region”, Water and Rivers
Commission, Water Resource and Planning Series, Report No WRAP 7.
Pen,L. 1999
“Managing Our Rivers”, Water and Rivers Commission, 3
Plain St East Perth, WA 6004.
Schofield, N.J. 1989 “Stream Salinity and its Reclamation in South-West Western
Australia”, Water Authority of Western Australia Report No WS 52
Taman, L 2000 notes compiled from “Rushes and Sedges Workshop”
Native Environmental Systems, Perth Western Australia.
26
Appendix 1
Location Maps of
Two Peoples Bay Nature Reserve
and Catchment
27
Appendix 2
Aerial Images of Angove, Moates
and Gardner Lakes
28
Appendix 3
Wetland Aerial and Ground photographs, 2003
29