Sherman lakes chosen for walleye experiments

By RICHARD JENKINS

rjenkins@yourdailyglobe.com

SPRINGSTEAD — Two Iron County lakes have been selected for an experiment researchers hope will lead to stopping the decline of walleye populations across the state of Wisconsin.

Wisconsin Department of Natural Resources fisheries biologist Zach Lawson said he was notified March 20 McDermott Lake and Sandy Beach Lake in the town of Sherman were selected for a five-year experiment conducted by the DNR, University of Wisconsin’s Center for Limnology and the Cooperative Fisheries Research Unit at UW-Stevens Point. The experiment will spend several years reducing McDermott Lake’s panfish population in hopes of increasing walleye numbers.

“The field work is going to start this year — this spring — but this year will soley be background data collection,” Lawson said. “There won’t any removal, any experiments starting this year and the actual removal of (panfish and bass) is starting next year.”

The decline in walleye populations across Wisconsin is happening at the same time bass and panfish numbers are increasing, according to Tyler Tunney with UW’s Center for Limnology in Madison. Tunney and the other researchers held a meeting in Mercer in February to discuss their proposal to remove as much as 80 percent of the bass and panfish from the lake to see if the walleye numbers rebound. They are theorizing the targeted species are either eating young walleye before they reach maturity and reproduce, or are simply outcompeting them for food.

While they acknowledged they aren’t sure what is causing the population decline, the researchers said predation is a theory because they’re observing walleye in the early stages of their life cycle that then disappear.

Lawson told the Daily Globe McDermott has been chosed as the test lake, while Sandy Beach is serving as a reference lake. This means while it will be studied, Sandy Beach’s fish populations won’t be altered to allow it to serve as a control group.

The lakes met a number of criteria Tunney and the other researchers at the meeting said they were looking for; including a history of walleye presence, being roughly 200 acres or less, scientific data to indicate what populations were over time to establish baselines, a consistent pattern of walleye followed by a decline and relative isolation to prevent fish from easily entering or exiting the body of water. Support from the public and local DNR officials was also key.

The members of the public in attendance at the meeting, mostly McDermott Lake residents, were generally in favor of the lake being selected for the experiment.

“I’ve been fishing that lake for many, many years. Forty years ago, (it) was a decent fishing lake — there were good numbers of walleyes, but only because people were putting them in there,” said Dan Luke. “Lately, walleyes just seem to be non-existent. There could be a couple in there, here and there you might hook into one. But everything in that lake is stunted.”

By not removing any fish in the first year, Lawson said it will give the researchers a necessary baseline for the lake’s fish populations.

“This year is kind of (to) get a good picture of what the fish community looks like in there, what each population level is like — exactly how many walleye are there in there currently, how old are they and how well are they reproducing; and then the same for largemouth bass, same for blue gill, same for pumpkinseeds,” Lawson said. “Once you kind of put that whole picture together this year, you start to remove fish next year and you can track what’s going on.”

After the baseline is established, researchers will spend three years removing panfish and bass, through a number of methods; including netting and electrofishing. While McDermott Lake has already had catch limits on bass removed, similar restrictions on panfish could also be eliminated to encourage sport fisherman to assist with the effort.

The fifth year of the study could either include additional removal efforts or simply assessing the results of the experiment. If additional funding is secured, Tunney said the project could either be extended or a new question studied — depending on results.

Other species, such as muskie and perch, won’t be dealt with in the study. Tunney said they don’t think it’s part of the problem but could be looked at as a followup project if the initial plan doesn’t work.

He did acknowledge muskie could increasingly target walleye as the other fish species are removed from the ecosystem. Lawson said at the meeting walleye stocking will continue as planned through the experiment, with McDermott Lake scheduled for stocking this year.

Further aiding the researchers will be the fact the DNR already has pretty good data on both lakes, Lawson said, which provides a broader historical picture into the long-term population trends.

While some may prefer fishing bass or panfish, Tunney said at the meeting the study was being done in response to concerns they were hearing from people around the state.

“I’m not advocating walleye over bass, or walleye over panfish. It’s just we hear (from people), we know walleye has a special kind of place in people’s hearts in Wisconsin,” he said.