Inland lake and stream surveys provide DNR with crucial data on Michigan’s fisheries

If you were out on the water last year, you may have seen some of your fishing license dollars hard at work — in the form of Michigan Department of Natural Resources fisheries management units busily completing more than 280 fisheries surveys across the state. Crews completed 179 surveys of inland lakes and 110 surveys of streams in 2024.

Collecting key data on Michigan’s fisheries is critical for successful management of the state’s diverse fisheries. These surveys help track inland fisheries populations, evaluate stocking efforts to increase angler opportunities or address concerns from the public.

“The fisheries management units performed inland fisheries surveys to evaluate if management actions, like fish stocking or habitat improvement projects, had the desired effect,” said Jim Francis, DNR Fisheries Division Lake Erie basin coordinator. “Survey data helps us understand whether our management actions resulted in better recreational fishing in certain areas or improved the overall health of a lake or stream.”

DNR inland fisheries surveys fall into three categories: evaluating management actions, understanding status and trends and finding answers to new questions or concerns.

Fish population abundance is estimated and in-stream habitat data is collected annually at fixed status and trends sites — usually trout in coldwater streams and smallmouth bass in warmer waters — on a three-year rotation. The DNR also performs random site surveys, which are intended to give a species snapshot and show relative abundance.

Discretionary surveys are used to answer questions or address current concerns that may have been raised by a local biologist, angling group or lake association. Such surveys, which usually account for 50% of the department’s annual survey effort, might be conducted to assess habitat suitability for threatened and endangered fish species.

Critical fisheries management activities such as surveys are at risk of reduction due to funding shortfalls. The DNR’s ability to regularly complete the surveys is dependent on sufficient, sustainable, long-term funding.

“Under our current funding level, an inland lake in Michigan is likely to be surveyed only once every 90 years. This affects our ability to deliver on our public trust responsibilities to Michiganders and needs to be addressed,” said DNR Fisheries Division Chief Randy Claramunt.

Increasing the survey frequency on lakes and streams is a goal of the division, but it depends on increased funding.

“DNR fisheries managers use the information resulting from all types of surveys to strategize actions, detect early indicators of invasive species, recognize developing threats to fish and habitat health, and much more,” Francis said.“Anglers rely on information from these surveys when planning fishing trips, and a number of partners depend on survey findings to inform strategic efforts such as habitat protections. Healthy, high-quality aquatic ecosystems and waters benefit everyone.”

If you’d like to learn about the DNR’s lake and stream surveys, especially in your part of the state, contact the fisheries management unit in your area. For more on how the department takes care of fisheries, visit the DNR’s fisheries management webpage.

An accompanying image is available below for download. Caption information follows. Credit: Michigan Department of Natural Resources, unless otherwise noted.

• Stream survey — Michigan Department of Natural Resources crews completed 179 surveys of inland lakes and 110 surveys of streams in 2024.