Home Biologist MNR has determined how many lakes and streams in Michigan have healthy fish

MNR has determined how many lakes and streams in Michigan have healthy fish


Surveys of Michigan’s lakes and streams are underway in parts of the state, as part of the state’s annual effort to collect data to better manage fisheries resources.

Michigan’s 10,000 lakes and 36,000 miles of rivers are teeming with data, Michigan Department of Natural Resources officials say, but the department only has enough staff to conduct about 250 to 300 surveys a year. .

Jay Wesley, DNR Fisheries Division Lake Michigan Basin Coordinator, said DNR crews completed more than 260 fisheries surveys in Michigan in 2021. DNR fisheries staff surveyed 152 lakes inland and 115 waterways.

Wesley said surveys have found about 80% of lakes and streams in the state have healthy, self-sustaining fish populations.

The surveys, which are underway in southern Michigan and begin in May in the Upper Peninsula, are useful for tracking inland fishery populations, assessing whether stocking is increasing angling opportunities or addressing angler concerns. throughout the year, Wesley said.

“Management units stepped up last year and conducted these surveys safely to assess whether management actions, such as stocking or habitat improvement projects, were having the desired effect,” said Wesley. “Surveys help us understand whether or not our management actions have resulted in better recreational fishing in certain areas or improved the overall health of a lake.”

Other annual surveys help managers track the status and trends of fish communities and important aquatic habitats on different lakes, Wesley said, providing a picture of the lakes environment over time.

Statewide streams are managed by two types of surveys called fixed sites and random sites.

“At fixed sites, we estimate fish population levels, typically trout in colder waters and smallmouth bass in warmer waters, on a three-year rotation, while random surveys at the sites provide insight into species and show relative abundance,” Wesley said. “The MNR collects habitat data at all surveyed sites.”

Fisheries managers use discretionary surveys to answer questions or respond to current concerns, such as an issue raised by a local biologist, angler group or lake association, Wesley said.

These surveys can be conducted to assess habitat suitability for a threatened or endangered fish species and typically represent 50% of the annual survey effort, state officials said.

Wesley said the information is used to strategize management actions, detect early indicators of invasive species, and recognize developing threats to fish health and habitat.

“Most of our funds come from fishing license fees, so we want to make sure these lakes have healthy fish populations,” Wesley said. “If not, we want to know what we can do to improve them.”

“In general, people are curious about what’s in their lake and how it’s doing,” he said.