Winter fish kill hits northern lakes

Long Lake in Florence County as seen on Thursday, April 10, 2014. (WLUK/Eric Peterson)
Long Lake in Florence County as seen on Thursday, April 10, 2014. (WLUK/Eric Peterson)

LONG LAKE - Even though temperatures are warming up, wildlife biologists are bracing for potential fish kills across the state.

Thick ice continues to blanket many area lakes, making it tough for fish to breathe.

That includes Long Lake in western Florence County where DNR biologists have already found hundreds of dead fish.

"All that stuff on the surface, that kind of looks like ice or vegetation, that's all fish," said Greg Matzke, DNR fisheries biologist.

In a sliver of open water on the shoreline of Florence County's Long Lake, DNR fish biologist Greg Matzke says hundreds of fish have suffocated.

"They look to be mainly pan fish, I see lots of perch," said Matzke.

Matzke is says the 340 acre lake is mostly shallow and weedy.

Fisheries technician Brad Shucha tested conditions Thursday morning.

Matzke says thirty inches of ice blanket underwater vegetation, killing the plants, and robbing the lake of oxygen.

"So it's kind of a double-whammy. So on our shallower lakes where we have high vegetation, we're going to see some winter kills this season," said Matzke.

But people on the lake are fighting back.

"I would estimate it to be the size of a football field," said John Touchett, Long Lake Resort owner.

For the past 22 years, Touchett has kept an aerator running on the lake through the winter.

"This year, the oxygen levels in the lake apparently dipped down below what this can compensate for. So even though it's been working all winter, obviously it can only put so much effect into the lake," said Touchett.

But biologists say partial fish kills may not be all bad. They say it's nature's way of thinning out the underwater population.

"So the kill would actually reduce their population back to a normal level, and allow those remaining fish to have more food, grow faster, and produce more viable larger eggs," said Matzke.

Biologists say they won't know the extent of the fish kill until the ice melts. They say that may be another three weeks.

We checked with other fish biologists in the area. They say they have had few reports of fish kills, but they expect to see more in the coming weeks.