What Are Some Ways to Help Cold-Water Fish in Michigan?

Severe Winters

• Severe winters, with prolonged ice cover and snow on the Great Lakes, are the main cause of high death rates of fish. Winterkill occurs because the ice cover seals the lake from the atmosphere so it cannot recharge with oxygenated air. Fish gasp for air at holes in the ice and die. The numbers of dead fish are not apparent until spring, when shorelines are littered with them.

  You can help aerate the body of water by running outboard motors attached to docks or boats for four hours, then moving to another location. This will move water and thin the ice cover. Poking holes in the weakened areas also will help get oxygen into the lakes. Caution is advised because the ice may be weak. The motor should be left in deep water so the bottom is not stirred up. This is a short-term solution.

Nutrients

• Residents living on the lake year-round can help by keeping plant fertilizers out of it. These nutrients come from runoff of septic fields, fertilized farmland, wastes from livestock and waterfowl. The additional nutrients prevent cold-water fish from thriving. A long-term solution is to dredge the bottom of the lake, but this is costly.

Pollution

• Michigan is an industrial state with a steady growth of urban centers, which create chemical pollution. According to the Michigan Department of Natural Resources, watersheds and marshlands can reduce the impact of runoff from commercial, residential and agricultural sources. To help control runoff, you can plant trees, contact local officials about marshland drying up and educate schoolchildren about wetlands.

  The Great Lakes received a $9.2 million grant to help restore fish habitat. The funds will cover the costs of removing two concrete dams in Berrien to re-establish fish passage; constructing native-fish-spawning habitats in St. Clair; removing debris from Fordson Island, a fish and wildlife refuge in Detroit; and improving levees and canals, and building a structure for fish passage to restore coastal wetlands in Erie.

Invasive Species

• The rapid reproduction rate and size of Asian carp entering Lake Michigan poses a high risk to the ecosystem by killing off the cold-water species. To help save the native fish, regional and federal agencies are combining efforts to install an electric barrier to prevent the Asian carp from entering Lake Michigan.

  Non-native zebra and quagga mussels strip Lake Michigan of life-supporting algae. In addition, the population of Diporeia has been severely depleted by mussels. Diporeia resemble tiny shrimp and are the base for the Great Lakes food web. Scientists are trying to decide the best approach to rid the lakes of mussels.

  According to the National Oceanic and Atmospheric Administration, you should inspect boats and trailers for mussels and aquatic vegetation and discard them in the trash can. Drain all water from boats, including that in the engine cooling system. Dry the boat and trailer and discard bait in the trash. These measures will help stop the spread of mussels

Parasites

• Sea lampreys are an invasive species of parasites. Equipped with a tooth-studded oral disk, the sea lamprey attaches to the side of native trout, and chews a hole through the skin. The host often dies from blood loss. Michigan State University, the University of Guelph in Ontario and the Hammond Bay Biological Station have discovered that breaking the life cycle is the key to controlling sea lampreys.