Fish of the Great Lakes

The Great Lakes form the largest freshwater system on Earth by surface area - 244,000 square kilometers of navigable inland sea. From the deep, cold waters of Lake Superior (holding 10% of the worlds freshwater) to the productive shallows of Lake Erie, they support commercial fisheries, tribal treaty rights, and world-class recreational angling.

Five interconnected lakes: Superior, Michigan, Huron, Erie, Ontario. Drained by the St. Lawrence River into the Atlantic. Shared between the US and Canada. Formed by glacial retreat 10,000+ years ago.

Native lake trout, walleye, yellow perch, smallmouth bass, muskellunge, northern pike, lake whitefish. Non-native but naturalized brown trout, rainbow trout, chinook salmon, coho salmon. Invasive: sea lamprey, alewife, round goby, quagga and zebra mussels.

Native fish populations decimated by 1950s from overfishing and sea lamprey invasion. Chemical loading peaked in the 1970s, then declined with the Clean Water Act. Modern threats: invasive species, agricultural runoff (Erie algal blooms), climate change.

Invasive Asian carp threatening to enter via Chicago waterways. Agricultural nutrient loading in Lake Erie. Sea lamprey (controlled but persistent). Warming waters.

Ice fishing December-March. Walleye pre-spawn spring runs April-May. Salmon peak in late summer. Trout year-round in tributaries.

Chartered trolling for salmon, lake trout, and walleye is world-famous. Tributary fly fishing for steelhead ranks among the best in the world. Licenses required in each state and province.

Home to Ojibwe, Odawa, Potawatomi, Menominee, and other Anishinaabe peoples for millennia. The fur trade routes ran through here. Erie Canal completion in 1825 transformed the region economically.