Fall electrofishing surveys to start soon as DNR checks on young walleye

Planning to be on the water this fall? Be on the lookout for Michigan Department of Natural Resources personnel conducting nighttime walleye recruitment surveys from late September to mid-October.

These surveys are an important tool for fisheries managers to determine whether walleye that hatched in the spring (known as young-of-year) hatched in the wild or were stocked, as well as how many of those fish are present in an area. This information about the status of young walleye in lakes helps the DNR make informed management decisions.

Using electrofishing boats, crews will survey shallow areas near the shoreline of lakes at night with the goal of capturing young-of-year walleye. Walleye prefer cooler, deeper areas of lakes during the day but move into shallow, nearshore areas at night, making nighttime surveys more efficient. On larger lakes, two or more electrofishing crews using separate boats may operate at the same time to cover more area. The crews will work both on lakes that have been stocked with walleye and lakes that have not.

Biologists also will collect and keep a sample of young-of-year walleye from stocked lakes to determine whether the fish are primarily reproducing naturally or if young-of-year are from stocking. Many walleye that are stocked are marked with oxytetracycline, a chemical marker that can be observed within captured fish by using a microscope with an ultraviolet light source in a laboratory setting. In addition, modern genetic techniques that allow more accurate assessment of stocking success will be completed at Michigan State University on walleye tissue samples collected during some of these fall surveys.

Some surveys will be conducted collaboratively with tribal agencies, and tribal natural resource departments also will be conducting surveys independently of the DNR. In the Upper Peninsula, the U.S. Department of Agriculture’s Forest Service also will be collaborating on surveys and conducting independent surveys in the Hiawatha National Forest as part of an effort to create long-term datasets for a number of inland lakes managed for walleye.

Everyone is urged to use caution when fishing or on the water near electrofishing boats, and those wading will be asked to exit the water when a survey boat approaches and during electrofishing work. Crews will be using bright lights to illuminate the water around the boats and running generators on board, which may make it difficult to hear and speak with anyone on shore.

Learn more about how the DNR manages Michigan’s walleye fisheries at Michigan.gov/Walleye.

An accompanying photo is available below for download. Caption information follows.

• Nighttime survey — A Michigan Department of Natural Resources crew conducts a nighttime electrofishing survey.