230 likes | 238 Views
The in-lake habitat of lake trout is thriving with abundant fish populations, including whitefish, herring, sturgeon, and walleye. Achieving fish community objectives through sea lamprey control, restoration efforts, and addressing pollution concerns like mercury and PCBs. Research priorities include species interactions, genetics, and sustainable management strategies.
E N D
Where to From Here Mark P. Ebener Chippewa/Ottawa Resource Authority
Take Home Message The System is in Good Shape!!
In-lake Habitat in Good Condition
All forms of lake trout Abundant 350 300 250 200 Kilograms per Kilometer Siscowet 150 100 Lean 50 0 1950 1960 1970 1980 1990
Lake Herring Partially Recovered 700 600 500 400 CPUE (kg/km) 300 200 100 0 1973 1978 1983 1988 1993 1998
Sturgeon, Walleye, & Brook Trout Present >Increasing in Abundance >Sturgeon & Walleye widespread
Invasive Species >Recent Invaders Benign >Sufficient Buffering Capacity Present Fish Community
Achievement of Fish Community Objectives • Balance Sea Lamprey Control & • Rehabilitation Native Fishes • Passage for Sturgeon & Walleye • Native Lampreys in Canada • Sturgeon Treatment Protocol
Achievement of Fish Community Objectives 2. Tributary Restoration & Protection • Rehabilitation Sturgeon, Brook Trout, Walleye • Require Watershed Mgt Plan • Coalition Building • governments, interested citizens, agencies • Long-term prospect of 50+ years
Achievement of Fish Community Objectives 3. Fish Consumption Advisories Inevitable • LaMP Load Reductions not sufficient Mercury 60% by 2000 100% by 2020 PCBs 33% by 2000 100% by 2020 Dioxin 80% by 2005 100% by 2020
Achievement of Fish Community Objectives 4. Effective Ballast Water Management • Non-indigenous species will continue to arrive • Address vectors for future invasions
Achievement of Fish Community Objectives 5. Lack of Information • Lack abundance & biomass estimates • Lake trout • Lake Whitefish • Siscowet • Pacific salmon • Walleye • Lake herring & chubs • Burbot • Sucker
Achievement of Fish Community Objectives 6. Define appropriate harvest levels • Is 40% mortality correct for lake trout • Is 65% mortality correct for whitefish • Target fishing mortality for herring • most at risk species
Achievement of Fish Community Objectives 7. Agency Commitment • Hinder information gathering & evaluation • Ontario commitment lacking many years • State Governments downsizing
Future Research Needs >14 Different Recommendations • Assessment • Habitat Restoration & Evaluation • Species Interactions • Genetics and Stock Structure • Fish Community Structure • Lake-wide Lake Trout Model • Sea Lamprey Control
Research Needs • Research & Assessment • Offshore waters • Acoustic, trawling, gill nets, hooks • Estimate abundance pelagic & benthic species • Understand habitat use • Role in supporting sea lamprey production • Understand trophic interactions
Research Needs • Map in-lake & • tributary habitat • Link habitat & fish • Evaluate carrying capacity • Ability to achieve FCO’s
Research Needs 3. Understand Species Interactions • Pacific salmon & brook trout • Sea lamprey host selection • Siscowet & lean lake trout
Research Needs 4. Understand genetic & stock structure • Lake trout form differentiation • Stock boundaries • Number Lake herring stocks • Brook trout population genetics • Lake sturgeon genetics • Deepwater ciscoes differentiation
Research Needs 5. Understand Fish Community Structure • How physical & chemical parameters shape it • Connection of prey to lower trophic levels • Relate community to habitat in FCOs
Research Needs 6. Develop Lake-wide Lake Trout Model • Determine rehabilitation limits • Estimate Harvest Limits • Evaluate Sea Lamprey Control • Evaluate Mortality Targets • Evaluate Management Strategies
Research Needs 7. New Sea Lamprey Control Techniques • Pheromones • Native Lampreys • Innovative Barriers • Selection of Streams for Treatment • Control Lentic Populations • Increase Frequency of Treatments
Future Fish Community • Brook trout populations resurge • No need to stock hatchery-reared fish • Lake sturgeon populations will increase • Illegal harvest of sturgeon will increase • Demand for herring roe will increase • Habitat degradation will continue • Several new non-indigenous species