DNR eyes Green Bay for muskie fishery
Written by Appleton Post-Crescent   
Wednesday, 16 August 2006 15:34

To accomplish its major goal of establishing a fishery for big muskies on the vast waters of Green Bay, the state Department of Natural Resources is willing to think smaller — as in Duck Creek, the Suamico and Pensaukee rivers.

These minor tributaries on the bay's west shore may hold a key to muskie reproduction, the final building block needed to fully re-establish the spotted or Great Lakes strain of muskie in Wisconsin waters of Lake Michigan.


"We're hoping to improve natural spawning activity," said Kevin Kapuscinski, DNR fisheries biologist in charge of the muskie re-introduction.


The three streams were added this summer to sites the agency has stocked with muskie fingerlings since the restoration project began in 1989.


While anglers and DNR survey crews have caught muskies topping 30 pounds in recent years, there has been no sign of successful spawning despite the obvious presence of adult fish.


"There may be something missing from our regular sites that these streams have that will encourage spawning," Kapuscinski said.


During the past 17 years, DNR crews have released about 116,000 spotted muskie fingerlings in the Fox, Menominee and Peshtigo rivers, along with waters off Sturgeon Bay, Little Sturgeon Bay and Communiversity Park just north of the city of Green Bay.


"We set three goals for the program," Kapuscinski said. "We wanted to increase the diversity of predators in the bay and we've done that. We wanted to produce a trophy fishery and we have that.


"And we wanted natural reproduction, a self-sustaining muskie population. We just don't have that natural reproduction ... yet."


Despite indications that spawning activity may have taken place, DNR crews have been unable to find young muskies that would indicate spawning has been successful.


"We do have reports of anglers observing muskie spawning activity in the Menominee River below the Hattie Street Dam," Kapuscinski said. "It may be possible there is some reproduction there. Anglers on Little Sturgeon Bay have reported seeing muskies swimming together during spawning season, and we know muskies are spawning in the Fox River. But there is a big difference between spawning and successful reproduction.


"I really feel the Peshtigo River offers the best opportunity for successful muskie spawning."


Kapuscinski is intrigued by the possibilities offered by Duck Creek, the Suamico and Pensaukee rivers.


"The majority of muskies were stocked in the Menominee and Fox rivers," he said. "They are the largest rivers entering the bay but they are also the most altered (by pollution, seawalls and other human activity).


"The smaller rivers are a lot more natural and have vegetation" the larger rivers lack.


They also enter the bay adjacent to large, shallow, weedy areas that may be more suitable for muskie spawning and the survival of emerging fry.


To enhance survival of stocked muskies, the DNR releases well-fed fingerlings or yearlings 12 to 22 inches long, but the volume of the release is low, often fewer than 100 fish per site when the larger yearlings are involved. Fewer than 2,800 yearlings have been released.


All yearling muskies released this year were fitted with passive integrated transponder (PIT) tags inserted under the skin. The tag, about the size of a grain of rice, is virtually invisible and coded to allow researchers to determine a muskie's growth rate and movements when the fish is captured.


In the past, a small external "Floy tag" has been used to mark released muskies. It provides information when anglers report the tag number and fish's location or DNR personnel recapture a tagged fish.


If efforts fail to produce successful spawning, the DNR will continue to search for a solution.


"We will then need to examine the reproductive sequences," Kapuscinski said. "Do we not have enough adult muskies in the bay for successful spawning? Do we not have enough suitable habitat? It may be that certain habitats aren't available ... or that we're stocking fish in the wrong location. Is something wrong with our stocking? Are we holding fingerling muskie too long before releasing them? The longer you hold a fish before releasing it, the more likely it will lose some of its wild behavior. Are our stocked fish losing the ability to detect and utilize proper spawning habitat?


"We have to understand what it takes for spotted muskie to reproduce in Green Bay."

 
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