Walleye decline on Lac Vieux Desert puzzling

Eagle River, Wis. — Walleyes in one of northern Wisconsin’s most popular lakes – the 4,000-acre Lac Vieux Desert (LVD) – are in trouble, now numbering an estimated 2,000 fish, which is down from about 13,000 in 1990.

Why the decrease? No one knows for sure. Not yet.

The combination of stocking, regulated tribal spearing, study of natural reproduction, and setting daily bag limits for hook-and-line anglers are all things Steve Gilbert, of the Wisconsin DNR, continues to work with on Lac Vieux Desert. While LVD sits primarily in northern Vilas County near Land O’ Lakes, part of the lake drifts into Michigan’s Upper Peninsula. The Michigan DNR is also involved.

So is the Great Lakes Indian Fish and Wildlife Commission (GLIFWC), since LVD is in the ceded territory. The Wisconsin Valley Improvement Company (WVIC), a utility company from Wausau, owns and operates dams on the upper Wisconsin River, including the LVD dam.

Despite the entities involved in this puzzle, including the local lake association, Gilbert is still the lead dog in this hunt since he was the DNR’s Vilas County fish biologist for years and now serves as the area’s fisheries supervisor.

Gilbert is getting help, though. Aaron Shultz, a GLIFWC biologist, and  Gilbert are trying to remain positive regarding natural walleye reproduction on this border lake.

Unfortunately, numbers aren’t showing positive signs in restoring the 4,017-acre LVD to its former status as a top-tier walleye fishery.

The bad news rolled out of the results from a late fall 2016 electro-fishing survey by the DNR and GLIFWC. Both agencies use fall shocker boat runs to gauge spawning success from the previous spring. Once water temperatures fall to 60 to 62 degrees, young-of-the-year (YOY) fish move into the shallows, walleyes included. Electrodes drifting in the water send out a gentle electrical current that stuns fish long enough to be dip-netted and counted. A count of 30 YOY walleyes per mile of shoreline is a decent sign of successful natural reproduction; 60 or more would be a great sign of survival.

“LVD has never really been a high-density lake when looking at walleyes, but very few lakes of that size are going to be high-density lakes,” he said. “Our statewide guidelines sort of tell us we’d like to be around three to four walleyes per acre. Right now, we’ve been around 2.5 walleye per acre.”

Gilbert has worked with agents from Wisconsin and Michigan and the Lac Vieux Desert band in managing one of the area’s best overall and most diverse fisheries.

“This body of water has been a big issue for many years,” Gilbert said. “It’s a complex issue just because of the cast of characters involved – all with different concerns and issues.”

Recently, Shultz released a study stemming from last fall’s surveys detailing troublesome times for LVD, which, he says in terms of population of adult walleye, has hit a 26-year low of just more than 2,000 fish.

By comparison, walleye abundance was at a high of an estimated 13,000 fish in 1990.

“We are continuing the search for clues in the LVD walleye decline,” Shultz said. “The results of the fall 2016 assessment were not encouraging.”

The assessment indicated that no 2016 walleye hatchlings survived to September.

“Not any,” Shultz said. “To put these results in context, consider that in the late 1980s and early 1990s the relative abundance of that same age walleye was about 30 per mile of shoreline. That number more than doubled to over 80 (YOY) per mile of shoreline by the mid-to-late 1990s.”

Gilbert’s studies show the same.

Since 2011, the Wisconsin DNR has stocked 180,347 small fingerlings into the system; however, natural reproduction of year classes has been almost nonexistent, according to DNR surveys.

“We pulled off some good natural years in 2002 and 2005, but since then it’s done almost nothing,” Gilbert said. “We’ve inspected and tested water quality, researched weather, studied rainfall and snowfall amounts trying to figure out what is the trigger.

“The lake has all the things needed to be a good walleye fishery. We just can’t put our finger on what is the exact problem with the natural reproduction of the lake.”

There are many possible causes for low walleye numbers that Shultz and Gilbert continue to look at as a possible root cause for the LVD walleye mystery.

Both entities have joined hands with the Lac Vieux Desert tribal resources unit, WVIC, the U.S. Forest Service, the Michigan DNR and officials with the local lake association to try to help.

Some are providing money for stocking efforts; others are helping change habitat and water flow to see if somehow the management team can find the right set-up.

“Clearly, management actions have to be taken to conserve dwindling walleye stocks and restore walleye natural reproduction in LVD,” Shultz said. “Anglers from Michigan and Wisconsin have enjoyed catching walleyes with hook-and-line. Unfortunately, catch and harvest has declined considerably in recent years, with many anglers and tribal members suggesting that the walleye population has crashed in the lake.”

Those involved

WVIC has worked to continue providing healthy water levels to increase spawning habitat – all while attempting to help implement a 10-year wild rice plan with the LVD tribe.

Back in the early 2000s, WVIC agreed to reduce the reservoir’s maximum water level by about nine inches, and to contribute $200,000 toward the planting and monitoring of wild rice.

“WVIC has been great through this process, being very willing to work with us and keep water levels as stable as possible for wild rice,” Gilbert said. “With that, though, it’s reduced the amount of shoreline habitat for spawning – a constant cat-and-mouse game between interest groups.

“Folks have tried different things in reference to spawning habitat, but had very limited success,” Gilbert said. “It doesn’t seem to be that habitat is limited, so we are still not sure where the problem lies with walleyes not naturally reproducing.”

Although rice had once been abundant at Lac Vieux Desert, it had almost completely disappeared by the 1950s.

Officials with the Forest Service and LVD tribe attributed that decline to the high water that resulted when WVIC rebuilt the reservoir’s dam in 1937, and correspondingly concluded that decreasing the reservoir’s water level would create conditions favorable to the self-sustaining growth of wild rice.

“As you can see, there are a lot of other people who have an interest in this body of water, for different reasons,” Gilbert said. “The wild rice project on the north shore is something we’ve also had to keep our eyes on.”

Being that the dam is federally regulated in accordance with FERC (Federal Energy Regulatory Commission) guidelines, hydroelectric power is also something that has to be evaluated when moving water downstream on the Wisconsin River.

Stocking increases have helped, but regeneration of year classes has been nonexistent while continuing to be a point of emphasis for not just the DNR, but LVD lake association members and resort owners who would like nothing more than to see their guests experience high success rates when fishing.

Tribal harvests have also been a point of contention.

Between members of the LVD, Mole Lake and Lac du Flambeau bands, a total of 17,935 walleyes have been speared since 1985 – 12,313 were by Mole Lake.

Low numbers prompted the Lac Vieux Desert band to eliminate member walleye harvest in 2010-11 and since 2013.

The Lac du Flambeau band has not speared the lake since 1997.

There were two 7 p.m. public meetings scheduled: Tuesday, April 4 at the Land O’ Lakes Elementary School, and Thursday, April 6 at the Phelps school.

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