DNR officials warn of major fish kill at Big Eau Pleine Reservoi - WAOW - Newsline 9, Wausau News, Weather, Sports

Wisconsin outdoor officials are worried about what might happen to a popular fishing spot.

The Wisconsin Department of Natural Resources first noticed a problem with the Big Eau Pleine Reservoir in January.

"Over the last couple of weeks we've had oxygen levels pretty much plummet down to less than one part per million, which is pretty low," said Tom Meronek, DNR Fish Biologist. "Fish typically need about 5 parts per million to live."

Now DNR biologists say a severe fish kill is likely.

Fish kills are not uncommon to the area. Officials say in 2009, 60% to 70%of the population in the reservoir died But the DNR predicts this year could be worse.

"There's really two things," said Meronek.  "The low water level probably contributed, the drought. And the other thing would be, we had a fish kill in 2009, I think we had a little less snow cover on the reservoir."

That snow cover stops oxygen from reaching the water. Biologists have been forced to take things into their own hands, pumping air into the reservoir as a refuge for the fish.

DNR officials say it could take years for the fish population to bounce back. It's too soon to know how many fish may have died. Officials say they'll have a better idea once the snow and ice melt.