Michigan biologists have begun annual surveys of Great Lakes fish populations.
The Department of Natural Resources' Fisheries Division has four research vessels for crews that measure relative abundance, diet, survival rates and other characteristics of fish in the state's waters. The data guides management of fishery resources.
The research vessel Lake Char focuses on trout in Lake Superior, including the extent of sea lamprey attacks.
In Lake Huron, the vessel Chinook supports assessments of trout and walleye, along with broader fish studies in Saginaw Bay and the St. Marys River.
The vessel Channel Cat samples walleye, yellow perch and sturgeon in Lakes St. Clair and Erie.
On Lake Michigan, crews aboard the Steelhead evaluate salmon, whitefish, trout and perch. They also work with federal agencies to study forage fish abundance.