DNR catching, tagging walleye on Mille Lacs to estimate population

A study underway on Mille Lacs to capture and tag fish will help state scientists estimate the number of walleye in the popular destination lake.

The study involves using electrofishing at night to temporarily stun fish, then putting an identifying tag in their back.

After about five minutes, the fish recover and swim away. Later in the summer, the Department of Natural Resources will try to recapture those same fish, said Tom Heinrich, Mille Lacs area fisheries supervisor.

"What we're looking for is the ratio of marked fish to unmarked fish," Heinrich said. "Based on that ratio, plus the number of fish that we tagged, we'll come up with a population estimate."

The last tagging study on Mille Lacs was done in 2013-14. The data collected from the latest study, along with other research methods, will help DNR officials determine how healthy the lake's walleye population is and how many fish can be safely harvested.

Heinrich said DNR officials worried they wouldn't be able to catch enough fish for the tagging study this year because of the ice that still covers much of the lake.

However, Heinrich said they started last Wednesday and already have tagged between 6,000 and 7,000 walleye.

"The goal is we'd like to get somewhere over 12,000 by the weekend," he said.

Anglers won't be able to keep any of the walleye they catch on Mille Lacs after the season opens on Saturday, however. Walleye fishing will be catch-and-release only for the third consecutive season.

DNR experts say the conservative regulations are needed to help protect the lake's walleye population, which has been in decline in recent years. The restrictions have been controversial with business owners that depend on walleye anglers for their livelihood.