DNR inland fisheries surveys are critical to management | News

Stocking fish, protecting lake habitat and adding or removing regulations are desired outcomes of Michigan Department of Natural Resources fisheries surveys.

Collecting data on Michigan’s fisheries is critical for the successful management of the state’s diverse fisheries resources. Michigan Department of Natural Resources fisheries management units completed over 260 fisheries surveys across Michigan in 2021. Specifically, DNR fisheries staff surveyed 152 inland lakes and 115 streams. None of the surveys, however, were conducted in the Cadillac area.

Overall, the surveys revealed that most of our lakes and streams have healthy, self-sustaining populations of fish.

The surveys are useful for tracking inland fisheries populations, evaluating if stocking increases angler opportunities or addressing concerns from anglers throughout the year.

According to Jay Wesley, DNR Fisheries Division Lake Michigan basin coordinator, surveys fall into three categories: Evaluating management actions; understanding status and trends; and finding answers to new questions or concerns.

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

Streams throughout the state are handled a little differently through two types of status and trends surveys: fixed sites and random sites.

Fisheries managers use discretionary surveys to answer questions or address current concerns. These can be something raised by a local biologist, an angling group or a lake association. Such surveys might be conducted to assess habitat suitability for a threatened or endangered fish species and typically account for 50% of the annual survey effort.

No matter the type of survey, DNR fisheries managers use the resulting information to strategize management actions, detect early indicators of invasive species, recognize developing threats to fish and habitat health and much more.

DNR Fisheries Biologist Mark Tonello said surveys have helped local lakes a lot. One prime example is the surveys done on lakes Cadillac and Mitchell.

“Going back to 2003 when we surveyed lakes Mitchell and Cadillac, that is when we found the natural reproduction of walleye had basically stopped,” he said. “Being able to go in and look at fish in real-time, collect data, see how they are growing and see how certain species are doing is vital.”

Tonello also said the surveys help biologists look at the lakes where fish stocking is happening and determine if the desired result is achieved. If the survey shows that it is, then stocking of the lake continues. If not, the DNR will stop the stocking program on that lake.

He said it allows the DNR to save time and effort. Armed with that information, the DNR also can focus on the lakes where certain species do well. Without a survey, it is difficult to do that, according to Tonello. An example is Big Bass Lake in Lake County.

“It’s called Big Bass Lake, but there aren’t any big bass,” Tonello said. “So we lowered the size limit on Largemouth Bass to accommodate that.”

While periodic surveys are important to overall lake health, Tonello said staffing is a problem and makes it harder and harder to survey lakes as often as they should.

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