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Great Lakes Fisheries

Great Lakes Fisheries. Presented by: Dr. Randal J. Snyder Associate Professor Buffalo State College snyderrj@buffalostate.edu. Key Factors: Overfishing. Peak harvests in late 1800’s were nearly 150 million pounds; only 63 million today

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Great Lakes Fisheries

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  1. Great Lakes Fisheries Presented by: Dr. Randal J. Snyder Associate Professor Buffalo State College snyderrj@buffalostate.edu

  2. Key Factors: Overfishing • Peak harvests in late 1800’s were nearly 150 million pounds; only 63 million today • Lack of management, improved fishing gear, other stressors • Key species: lake trout, sturgeon, Atlantic salmon, blue pike, whitefish, walleye, yellow perch

  3. Key Factors: Habitat Destruction • European settlement and urbanization • Deforestation: loss of cover, sedimentation, increased stream temperatures • Drainage of wetlands: loss of nursery habitat • Dams: block migration routes • Loss of habitat greatly impacted • Lake sturgeon in Lake Erie • Atlantic salmon in Lake Ontario

  4. Key Factors: Eutrophication • Cultural eutrophication: accelerated input of nutrients (esp. phosphates) into waterways, decreased dissolved oxygen • Fertilizers • Detergents • Water treatment plants • “Lake Erie is dead” in the 1960’s • Canada and US: Great Lakes Water Quality Agreement in 1972 • Phosphorus reductions very successful

  5. Key Factors: Toxic Pollutants • Increased use of synthetic organic chemicals since 1940’s – persistent in the environment • Dangers first evident with pesticide DDT • Increased risk of cancer, birth defects, genetic mutation • Fish consumption advisories

  6. Key Factors: Invasive Species • Canals (Welland, Erie) and ballast water • Notable invaders: sea lamprey, carp, smelt, alewives, Pacific salmon, round gobies, zebra mussels • Significant effects possible • Displace native species • Reduce biodiversity • Alter established ecosystems • Costs to industry Sea lamprey Round Goby Smelt and Alewife Zebra mussels

  7. Current Status of Great Lakes Fish Communities • Current fish communities are very different from historical communities! • Native top predators such as Atlantic salmon and Lake trout replaced by introduced Pacific salmon • Supported by hatcheries and stocking • Native prey species such as lake herring and bloaters replaced by exotic rainbow smelt and alewife Lake trout Lake herring

  8. Current Commercial Fisheries in the Great Lakes • Commercial fishing has declined significantly since its peak in the 1940’s and 1950’s • Important current species include • Walleye • Yellow perch • Lake whitefish • Rainbow smelt • Alewife (for animal feed) • Commercial fishing limited by toxic contaminants and pressure from recreational fishing interests Walleye

  9. Current Recreational Fisheries in the Great Lakes • Recreational or sport fishing has become very valuable in the Great Lakes region • Important species include • Pacific salmon (coho and chinook) • Walleye • Yellow perch • Largemouth and smallmouth bass • Northern pike and muskie Muskie Smallmouth bass Chinook salmon

  10. The Alewife and Pacific Salmon • Two exotic species in the Great Lakes that have had huge impacts • Pacific salmon (coho and chinook) introduced in Lake Michigan in 1960’s to control alewives • World-class pacific salmon fishery developed, but • Relies on continued stocking of salmon • Contaminants in salmon • Dependent upon an exotic species, the alewife • Obstacle to restoration of native species? Alewife Coho salmon Alewife die-off!

  11. The Round Goby – Our Newest Exotic Fish Invader • Small fish: 4 - 10 in. with fused pelvic fin • Native to Europe • Ballast water introduction around 1990 • Has spread rapidly, very aggressive and tolerant • Competes with native species (especially sculpins), may eat fish eggs • Good bait for bass, may have contributed to spread!

  12. Sea Lamprey Most destructive invasive species in Great Lakes history • Native to Atlantic Ocean and Lake Ontario • Spread throughout Great Lakes via canals by 1947 – major declines in Lake trout • One adult lamprey consumes 20-30 lbs of fish in its lifetime • Sea lamprey populations reduced by 90% by control programs – expensive!

  13. The Future of Great Lakes Fisheries • Overall health of fish communities slowly improving over time • Habitat protection and restoration • Reduction in pollutants • Better management • Restoration of native species (Lake trout, Atlantic salmon, Lake sturgeon) • Challenges remain • Fish consumption advisories • Exotic species Lake Sturgeon Great Lakes fishes are a valuable resource for current and future generations!

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