Biologists reviewing musky management to assure trophy fishing opportunities

MADISON -- With Wisconsin musky populations at historical highs and anglers catching them with fewer casts than at any other time in at least 40 years, state fisheries biologists are focusing on assuring the fish are trophy quality, at least in those waters managed to provide trophy fish.

Department of Natural Resources fish biologists and researchers and propagation specialists are mid-way through a project to evaluate stocking rates on musky waters in light of increasing catch and release fishing for musky and studies showing that overstocking a lake can result in high musky populations that grow slowly.

The biologists on DNR's musky committee are evaluating the results of higher minimum size limits on a variety of lakes. They also are developing a plan to evaluate alternate strains of musky including allowing some fishing groups as soon as this fall to stock different strains of musky in Lake Wissota, the Petenwell and Castle Rock flowages, and Lake Monona.

The major effort this year is to fully evaluate Wisconsin's program for collecting the wild fish, or "broodstock," to produce the offspring raised in state hatcheries and stocked in Wisconsin waters.

"We've got several efforts underway to improve our musky management programs, including starting a long overdue evaluation of the way we select fish for obtaining eggs for our hatchery system, " says Tim Simonson, a fish biologist who leads DNR's musky committee.

Genetic strain is one of several factors that determines the growth and size structure of muskellunge populations, and the analytical tools now available to fish geneticists are a lot better than just a few years ago, he says.

"We want to make sure we're using the fish that's going to provide the best fishing by maximizing survival and growth rates because that's why we're stocking those waters in the first place," Simonson says.

Wisconsin manages musky as a trophy fish, meaning its size limits are higher and bag limits lower than for many other species that grow more quickly. Those size limits, combined with a growing catch and release ethic and a hatchery system hitting its stride, have helped musky populations recover from a near collapse after three world record fish caught in the 1950s touched off a fishing frenzy. Now, monster musky are again being caught in growing numbers: In 2004, for example, the Vilas County Musky Marathon reported 17 muskies caught that were 50 inches or greater, Simonson says.

The state has 711 lakes and some 80 river segments that support musky fishing; the majority sustain naturally reproducing populations of musky but 200-plus waters do not and are stocked to maintain fisheries.

Wisconsin stocks fish hatched from eggs collected from wild fish every spring, Simonson says. The fish are native to the Upper Chippewa, Upper Wisconsin and Great Lake basins of Wisconsin, and have never been mixed with any strains from outside the area, Simonson says.

Brian Sloss, a University of Wisconsin-Stevens Point fisheries professor will be conducting the genetic studies, including identifying the genetic structure of Wisconsin's naturally reproducing populations, and where specific strains should be stocked to preserve the genetic integrity of the fish.

"One of the key questions, is, how many brood sources are needed in Wisconsin?" Simonson says. "Within the appropriate geographic areas, we'll use the most appropriate brood source lakes, based on the strain's population traits such as survival, growth, and trophy potential."

Minnesota took a closer look at their broodstock a number of years ago and realized they were stocking a slow growing strain of fish. They switched to a faster growing strain native to Leech Lake, a lake in north central Minnesota where anglers pull in a greater number of fish exceeding 50 inches.

Simonson cautioned that regardless of what strains Wisconsin stocks, the results won’t be the same as Minnesota's. "We're never going to produce as many 50 inch fish as a state like Minnesota because of the smaller size of our lakes, the forage type and abundance, and the greater fishing pressure in Wisconsin," he says.

Wisconsin may have 15,000 lakes, but only 268 are 500 acres or greater. Lake of the Woods, a popular musky water straddling Minnesota and Ontario, covers 1 million surface acres -- the total surface area of all Wisconsin's inland lakes. Leech Lake is roughly equal in size to all Wisconsin's Class A1 trophy musky waters combined.

Angler fishing pressure and harvest also affect Wisconsin size structure. While catch and release has really caught on, anglers are still keeping fish once the fish reach mid-40 inches, and fish that are released may die from the stress of fighting and handling. In fact, anglers responding to a random mail survey conducted by UW-Stevens Point in 2000-2001 reported harvesting 37,000 musky.

“On a typical 1,000 acre lake anglers can expect to find about 300 adult muskies and even under the best of circumstances, only one or two of them will reach 50 inches or greater,” Simonson says. "It doesn't take harvesting many of the fish at 45 inches to really affect the trophy potential."

Simonson stresses that Wisconsin has been managing musky for trophy potential overall, and will continue that management philosophy in the future. But anglers must keep in mind the various factors that determine the trophy potential of musky waters, not just the genetic strain of fish stocked, and that Wisconsin cannot ignore the other, ultimately more important tools of musky management: protecting habitat and fishing regulations.

"The strain used for stocking is clearly important in those waters that need stocking," Simonson says. "But there are no short cuts when it comes to managing for trophy musky, and job #1 is to protect our naturally reproducing populations of musky.

"They don't cost us much compared to stocked fisheries, which cost a lot to maintain through stocking, and fishing is generally better in naturally reproducing waters."

More information on musky management in Wisconsin can be found on the DNR Web site.

FOR MORE INFORMATION CONTACT: Tim Simonson (608) 266-5222

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