Spotted Musky Improvement Plan

From the DNR

MADISON – The 1,100 fingerlings that made the road trip from Ontario, Canada, to their new homes in three northeastern Wisconsin lakes are among new efforts this spring in the decades-long quest to restore a self-sustaining population of the Great Lakes strain spotted musky to Green Bay.

These young fish will eventually serve as broodstock for Green Bay.

Taken as eggs from Georgian Bay and later certified disease free, they were raised in the small, Sir Sanford Fleming College hatchery in Ontario, Canada and stocked into Elkhart Lake, Sheboygan County, and Anderson and Archibald lakes in Oconto County.

The $59,000 project, funded by the Wisconsin Department of Natural Resources, money from the Fox River environmental restoration settlement, Musky Clubs Alliance of Wisconsin, Muskies Canada and Titletown Chapter of Muskies Inc., is aimed at increasing the genetic diversity in Green Bay’s spotted musky population, which in turn will yield healthier fish, according to fisheries biologist David Rowe.

“Greater genetic diversity helps to protect a population from changes in their environment,” Rowe says. “If all the fish have the same genotype, they are all likely to succumb to the same illness or an environmental change like a warmer climate. If there is a great amount of diversity, the changes that impact some fish will not affect all fish in the population. This means the population can better adapt to changing conditions, and then they pass those stronger traits on to their offspring.”

The three receiving the Canadian fish have a 50-inch size limit to protect them, giving DNR multiple years to collect eggs before the musky would be vulnerable to harvest, according to Rowe.

A $200,000 grant from the Natural Resources Damage Assessment that resulted from the Fox River environmental settlement will allow the DNR to stock the Ontario-raised strain of musky into the recently established brood lakes for the next four years, which will continue to increase the genetic variation and abundance of the re-established Green Bay population.

Spotted musky are native to Green Bay, but the population collapsed in the early 1900s due to over-fishing, pollution and habitat destruction. Thanks to stocking efforts that began in 1989, the population in the bay is older and larger than ever, according to Rowe.

“The musky have grown fast in Green Bay’s waters,” Rowe says. “We estimate the population in the lower bay somewhere between 5,000 to 10,000 musky and just this spring we handled about a dozen fish larger than 50 inches in our nets.”

Even though the musky population has been revived and anglers are finding opportunities for trophy fish, biologists, who have been looking for signs of natural reproduction for 20 years, are just now starting to see hopeful results.

“Last fall, for the first time, we collected two, unmarked fingerling musky in the lower Menomonie River,” Rowe says. “We know from genetic analysis that these two had the same genetic markers as the adult fish from Green Bay, meaning they are Great Lakes Spotted muskies, and the first evidence of natural reproduction.”

To help determine why the DNR hasn’t seen more spotted musky reproduction, fisheries crews have begun a two-year study funded by the U.S. Fish and Wildlife Great Lakes Fish and Wildlife Restoration Act Program and several musky angling clubs including; Dave’s Musky Club, C&R Musky Club, Winnebagoland Musky Club, M&M Musky Club, Titletown Chapter of Muskies Inc., and the Between the Lakes Chapter of Muskies Inc.

This spring 20 female musky were inserted with miniature radio transmitters when they were captured during DNR fyke-netting. When those females spawn and expel their eggs, the transmitter will also drop, pinpointing their spawning location. This information will allow biologists to identify the area and see if there are any problems that might be hindering natural reproduction such as habitat degradation, poor water quality, or invasive species.