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Current Ecological Issues of the Great Lakes Jim Diana, Director Michigan Sea Grant College Program

Current Ecological Issues of the Great Lakes Jim Diana, Director Michigan Sea Grant College Program. The Great Lakes. 20% of world’s surface freshwater 5 of 9 largest lakes in world Historic role in transportation and settlement Large human population depending on the region

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Current Ecological Issues of the Great Lakes Jim Diana, Director Michigan Sea Grant College Program

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  1. Current Ecological Issues of the Great Lakes Jim Diana, DirectorMichigan Sea Grant College Program

  2. The Great Lakes • 20% of world’s surface freshwater • 5 of 9 largest lakes in world • Historic role in transportation and settlement • Large human population depending on the region • Multiple uses throughout history

  3. Take Home Message • Humans have had a love – hate relationship with the Great Lakes • The lakes have served for economic, societal, and ecological value since humans first set foot in this region • The lakes have suffered massive damage due to human misuse, both intentional and unintentional • The lakes have also rebounded dramatically due to human intervention and luck • Challenges remain for the future

  4. Early History • An important resource for aboriginal communities – food, water, and transportation

  5. Early History • An important transportation route for development and discovery of middle America

  6. Early European History • An important industrial resource for timber, waste disposal, shipping, and food

  7. An Important Point • By the early 1800s, the lakes were already dramatically altered (the Cholera epidemic)

  8. Clearing Wetlands

  9. Clearing Wetlands Wetland Forest Wet Prairie

  10. Ship Canals

  11. Dams Then Now Map courtesy of Troy Zorn, Michigan Dept. of Natural Resources

  12. Logging • Very common in 1900s • Easy to catch • Degraded habitat from logging • Extinct in Michigan by 1930.

  13. Fishing Lake Sturgeon

  14. Commercial Fishing

  15. Commercial Fishing High value Low value

  16. Pollution • Cholera epidemic of Chicago, 1854 • Sawdust, tannery effluent by 1900 • Eutrophication from sewage discharge in the early 1900s • PCB and DDT contamination from manufacture by 1960 • Serious water contamination from industry, sawdust to petroleum products and animal wastes • Airborne contaminants and contaminated sediments

  17. Pollution Time Magazine (1965) – “Lake Erie is dead”

  18. Invasions • Deliberate introductions • Carp, Pacific salmon The Common Carp

  19. Invasions • Unintentional introductions • Pink salmon, smelt

  20. Invasions • Immigration through ship canals • Sea lamprey

  21. Invasions • Immigration through ship canals • Alewife

  22. Invasions • Ballast water • Zebra mussel

  23. Invasions Round Goby Ruffe • Ballast water • Quagga mussel, water flea, goby Quagga Mussel Bythotrephes

  24. Salmon Fishing • Introduced 1969 to control alewife • Now multibillion dollar industry

  25. Rehabilitation 1966 1969 1972 No predators Overfishing Lamprey Massive Alewife Die-off Lake Erie is dead Cuyahoga River burns DDT Banned Lamprey Control Clean Water Act Salmon stocked DDT use banned 1976 1984 Salmon Control Alewives Lake trout Return PCB production banned Alewives Decline drastically Sport Fishery at $1 Billion

  26. The Future? – Lake Huron • In my view, this is the current ecological change that is most important to our future • Mussel invasion and increased water clarity • Reduced plankton and changes in food web • Loss of stocked salmonids • Rebound of native species • Change in economic conditions

  27. Mussels and clarity • Dreissenids consume energy and nutrients that supported fish • Round gobies have proliferated lakewide, can feed heavily on Dreissena

  28. Loss of Plankton

  29. Loss of Diporeia

  30. Change in Forage Fishes

  31. Loss of Chinook Salmon

  32. Rebound of Natives

  33. Rebound of Natives Do we change from a fishery supported by stocking to a much lower production of natural fish? Smallmouth bass • Similar trends in other native fishes

  34. Economic effects Estimated $19 million loss in 10 coastal communities

  35. Another Problem: Asian Carp • Imported by fish farms • Escaped into the Mississippi • Now very close to Lake Michigan • DNA in water of Calumet Harbor

  36. Other Comparable Changes • Botulism spread through the system • Increased growth of nuisance algae and harmful algal blooms • Dead zones in deep water of Lake Erie

  37. Summary • Dramatic deterioration and cleanup • Has required continual reaction and money input • Has resulted in significant improvement and environmental law • Needs continual intervention

  38. Contacts & Questions Jim Diana: jimd@umich.eduPhone: (734) 763-5834 Web: www.miseagrant.umich.edu

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