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1 2 Yukon Freshwater Fisheries Presentation to YFWMB April 2014 Nathan Millar Senior Fisheries Biologist 3 You asked • 5.2 The Board further recommends the Department of Environment… determine what can be done to enhance populations over the long term; • The Board has also requested a scientific presentation from the Department pertaining to the effects of harvesting fish species such as whitefish and burbot on the survival rates of young lake trout and lake trout eggs. 4 Today • • • • Impact of fishing: trends Status of populations What do anglers want? Options 5 Impact of fishing • • • • • We encourage angling & stewardship ( ) Number of anglers is steady ( ) Amount of fishing is steady ( ) Fewer fish are harvested ( ) Technology has changed – boats, gear ( ) 6 Status of populations How many? • 45,000 lakes >1 ha. (9,000 km2) • 8,000 lakes >10 ha. • 850 lakes > 100 ha. (e.g., Coal, Lacelle) • 75 lakes > 100 ha. (e.g., Squanga) • 10 lakes > 1000 ha. (e.g, Frances) We have surveyed 115. We focus on the ones that get heavily fished and visit them repeatedly. 7 Distribution of Angling Effort in Yukon Hours Hours / ha Fishing effort / impact is not distributed equally across Yukon •Centred in Southern Lakes •Effort determined by access 33 fisheries where we have monitored harvest Lake/Fishery Jackson Twin (West) Lake Tarfu Lake Snafu Lake Caribou Lake Frenchman Lake Fox Lake Pine Lake Watson Lake Fish Lake Tatchun Lake Little Atlin Lake Kathleen Lake Braeburn Lake Ethel Lake Laberge Lake Marsh Lake Lake Size (ha) 65 160 405 651 32 1441 1660 548 1320 1320 654 4033 3376 558 4610 20100 9630 Year 2011 2013 2010 2010 1996 2012 2013 2009 2002 2010 2005 2008 2004 2001 2012 2007 2007 Estimated Hours Hours/ha. 757 11.65 1543 9.64 3141 7.76 3783 5.81 115 3.61 4564 3.17 5009 3.02 1185 2.16 2543 1.93 2376 1.80 750 1.15 4175 1.04 2265 0.67 299 0.54 2271 0.49 6706 0.33 3174 0.33 Lake/Fishery Kusawa Lake Simpson Lake Dezadeash Lake Quiet Lake Tagish Lake Teslin Lake Aishihik Lake Frances Lake Bennett Lake Kluane Lake Tagish Bridge Johnson's Crossing - Spring Kathleen River Lubbock River - Spring McIntyre Creek Nares River Lake Size (ha) 14200 2030 8250 5441 35460 35400 14500 9941 9680 39275 Year 2006 2002 2013 2011 2003 2008 2006 2009 2009 2004 2007 2001 2004 2010 2004 2009 Estimated Hours Hours/ha. 4325 0.30 608 0.30 2429 0.29 1204 0.22 6888 0.19 6812 0.19 2456 0.17 1592 0.16 1020 0.11 2024 0.05 2420 322 3757 454 3190 2041 9 Status of lake trout 500 – 1000 lakes that contain lake trout Population assessments done on 115 Angler harvest surveys on 35 Most heavily fished populations ? ? ? Harvest is increasingly unsustainable Harvest is sustainable Summary: status of populations • • • • • • > 1,000 lakes with fishable populations 115 have been surveyed Most activity takes place on 30 – 60 (?) waters We know the harvest at 33 In most cases: the harvest is sustainable Where harvest is unsustainable: we work with RRCs, you, and anglers to develop and implement solutions 11 What do anglers want? When you go angling, what is important to you? What do you think are the most important things to Yukoner anglers, as a whole? 12 0 Ranking of Responses 5 10 15 Beauty of surroundings Quality of water Escape routine Access to wilderness Privacy (from other anglers) Weather conditions Angling for wild fish Number of fish caught Catch desired species Rec. Fish Survey 1985 Size of fish caught Catch as a source of food What most contributes to your enjoyment of sport fishing in Yukon? 1 Environment 2 Fish related 3 Fishing environment 4 Getting there 5 Socio-cultural 6 sport beauty, water quality, wilderness size, number, etc.) not crowded cost, ease of access enjoyment, family, relax challenge, excitement 13 Ranking of Responses 0 Lack of Pollutants in Fish Water Quality Lack of Angler Crowding Natural Beauty of the Area Absence of Other Recreationists Places to Fish From Shore Presence of Wildlife Presence of Favourite Species Size of Fish Information About the Area Variety of Species Available Catch Rate of All Fish Cost Distance/Travel Time Catch Rate of Fish You Can… Parking Availability Chance to Catch a Trophy Fish Boat Launching/Marina Tourist Facility Quality Nearness to Food/Lodging Access to Other Recreational… Nearness to Bait/Tackle Shops Availability of Handicapped… 1 2 3 4 5 Factors that play a role in determining where to fish Rec. Fish Survey 14 1990 and 1995 0 1 Ranking of Responses 2 3 4 5 To Enjoy Nature For Relaxation To Get Away Challenge and Excitement Family Togetherness To Catch Fish to Eat For Companionship Improve Your Skills For A Sense of Achievement To Catch a Trophy Fish Why anglers fish Rec. Fish Survey 1990 and 1995 15 0 10 Ranking of Responses 20 30 40 Uncrowded sites Lots of fish Ease of access Remoteness Large fish What is most important to your angling experience Rec. Fish Survey 2010 16 Summary: what anglers want • The natural environment, the fishing environment, sociocultural aspects are the most important • Fish-related characteristics, logistics, and sport are less important to most anglers • When it does comes to the fish: – – – – – – – Wild fish (1) Number of fish caught (2, 1) The ‘right’ species (3, 1) Size of fish / large / trophy (4, 2, 2, 2) Catch a fish to eat (5, 1) Variety (3) Catch rate (4) • The “Average” Angler doesn’t exist 17 Yukon Angler Psychographics The Nature Seeker -wants to get outside -some are good anglers, some aren’t -seeks appropriate setting The Family Experience Seeker -fishes as part of an outing or activity to get the family together -practices live release and keeps some fish -amenities often important -some are campground users The Experience/Sport Seeker -wants to catch a lot of fish -practices live release -typically an experienced angler The Dinner Seeker -wants to catch a fish to eat -doesn’t practice live release unless required -high frequency -fish close to home where possible The Holiday Seeker -fishes as part of an outing or other activity -some are campground users The Trophy Seeker -wants to catch large fish -typically an experienced angler -possible gear intensive 18 Questions Given that anglers want different experiences when fishing, what kind of a fishery (or fisheries) best meets these interests? Are some of these interests conflicting? What makes fishing in Yukon different from fishing elsewhere? 19 What can we do? Wild Populations Enhanced Populations Proactive regulations Yes Yes Responsive Regulations Yes Yes Stock Restoration Yes Stock Enhancement Yes Physical Habitat Restoration / Enhancement Yes Yes Chemical Habitat Restoration / Enhancement ? Yes Manipulation of Other Species ? Yes 20 Question Do you place a different value on a fish caught in a stocked lake and a wild caught fish? 21 Definitions Restoration Returning a population (or habitat) to a natural level Enhancement Moving a population (or habitat) beyond a natural level 22 Lake productivity • Primary productivity – Production of organic matter – Primary – at the base • All about energy flows • Root of all productivity: sun – Photosynthesis What are some of the environmental constraints to fish production that exist here? 23 http://www.sage.wisc.edu/atlas/maps/npp/atl_npp.jpg 24 Productivity in lakes • Temperature • Sunlight – Effect of ice • Nutrients – phosphorus and nitrogen • Geology 25 Experimental Lakes Area Lake 226 Phosphorus Eutrophication 26 http://www.experimentallakesarea.ca/images/Eutrophication.pdf Productivity across the landscape Productivity is low Limited by phosphorus and nitrogen Oligotrophic and mesotrophic 27 28 Fish Habitat Installed correctly Flood scours pool Mike Sullivan Fish Passage & habitat fragmentation: culverts Repeated floods = barrier Very expensive to fix Fragmentation 95% of watershed lost 2 species above 8 species below Ñ ò Baseline Creek watershed Athabasca River, near Hinton Craig Johnson (ACA) Mike Sullivan Question If you harvest a species it will help (or hinder) another species? 32 Fish Ecology • Competition • Predation Question: What do lake trout eat? 33 What lake trout eat in Yukon Unidentified Fish Non-Biting Midges Caddisflies Scuds, Sideswimmers Unidentified Invertebrates Least Cisco Pond Snails Unknown 1000 stomachs 34 lake trout burbot lake whitefish Juvenile lake trout lake chub Caddisfly (Tricopteran) sculpin round whitefish Midges (Chironomids) Copepod (planktonic) Gammarus (Amphipods / sideswimmer) Water mites Daphnia Clams Snails (gastropod) Dragonfly (Odonata) 35 35 What lake whitefish eat in Yukon Orb Snails Copepods Clams, Mussels Non-Biting Midges Snails Scuds, Sideswimmers Unknown Pond Snails Unidentified Invertebrates Caddisflies Leeches Water Mites Dragonflies, Damselflies 400 stomachs 36 lake trout burbot lake whitefish Juvenile lake trout lake chub Caddisfly (Tricopteran) sculpin round whitefish Midges (Chironomids) Copepod (planktonic) Gammarus (Amphipods / sideswimmer) Water mites Daphnia Clams Snails (gastropod) Dragonfly (Odonata) 37 37 Fish eat different things are different times of their lives: ontogenetic shift • Juvenile Lake Trout – Eat benthos – Suboptimal habitats • Adult Lake Trout – Eat fish 38 1. Egg Predation No literature confirmation Eggs that don’t descend have low survival anyway 39 1. Juvenile Predation The frying pan or the fire 3. Competition lake trout lake whitefish Copepod (planktonic) Caddisfly (Tricopteran) sculpin Midges (Chironomids) Daphnia Clams Gammarus (Amphipods / sideswimmer) Snails (gastropod) Dragonfly (Odonata) 41 41 Large bodied Eat fish Keep growing Tend to be in larger lakes Lakes haveNlake whitefish = 777 Small bodied Eat invertebrates Never get very big Tend to be in smaller lakes Lakes don’t have lake whitefish Others • Burbot – predatory and opportunistic – Also a sport fish • Round whitefish – opportunistic egg predators 43 Summary Many northern fish are generalist feeders Caveats Limitations on diet analysis – ‘point in time’, variation between fish, some items more digestible. Other techniques – stable isotopes of carbon and nitrogen provide time averaged Can you fish down predators and competitors • Species interact but not in simple ways – Dietary overlaps (competition) – Predation – Interactions can be positive for juveniles and negative for adults (for example) • There may be tradeoffs between – Species – Size v. number 45 References • • • • • • • Lasenby, T.A., S.J. Kerr, and G.W. Hooper. 2001. Lake whitefish culture and stocking: an annotated bibliography and literature review. Fish and Wildlife Branch, Ontario Ministry of Natural Resources. Peterborough, ON. Tolonen, A., J. Kjellman and J. Lappalainen. 1999. Diet overlap between burbot and whitefish in a subarctic lake. Ann. Zool. Fennici 36: 205-214. Beauchamp, D.A., M.W. Kershner, N.C. Overnman, J. Rhydderch, J. Lin, and L. Hauser. 2006. Trophic interactions of nonnative lake trout and lake whitefish in the flathead lake food web. Reportted to the Confederated Salish-Kootenai Tribes. Carl, L.M. 2008. Lake trout demographics in relation to burbot and coregonine populations in Algonquin Highlands, Ontario. Envrionmental Biology of Fish 83: 127-138. Fitzimons, J.D. 1996. The significant of man-made structures for lake trout spawning in the Great Lakes: are they a viable alternative to natural reefs?. Canadian Journal of Fisheries and Aquatic Sciences 53: 142-151 (Suppl). Hulsman, M.F. 2012. Influence of fish competitors on lake trout trophic ecology in subarctic lakes. M.Sc. Thesis. University of Alberta. Kerr, S.J. and T.A. Lasenby. 2001. Lake trout stocking in inland lakes: and annotated bibliography and literature review. Ontario Ministry of Natural Resources. 46 Stocking • Restoration / Enhancement • Divert Pressure • Yukon – – – – Pothole lakes – no outflow No stocking of open systems Limited supply of pothole lakes Previously fishless lakes Have you noticed differences in fishing in a lake that was stocked for the first time and that same lake a decade later? 47 20 Stocked Lakes 8% of all fishing 48 Some issues with stocking open systems • • • • • Genetics – do you stock the same species? Competition Disease Cost – initial, ongoing, monitoring Unintended consequences 49 A lake trout (mis)introduction • Yellowstone Lake • 1994 – Lake trout were first found – “bucket biology” Native Cutthroat Trout Solution – Lake trout suppression Active netting First 15 Years: 500,000 lake trout caught and eliminated 2011 and 2012: 525,000 lake trout caught and eliminated 2013: 172,000 in the first six weeks of the season Netting out the lake trout 50