MARSHFIELD, WI (WTAQ) - Another large fish kill is expected this spring on a reservoir that’s connected to the Wisconsin River between Marshfield and Wausau.
Tens of thousands of fish died in 2009 from a lack of oxygen on the Big Eau Pleine Flowage. And the state DNR says an even bigger fish kill is possible this spring – because the dissolved oxygen levels are much lower than those recorded four years ago.
Reports from ice fishermen say the fish kill may have started on the 7,000 acre flowage.
Experts say organic material and sediment suck the oxygen out of the water, and the ice prevents enough air and light to replenish that oxygen.
An aerator in the flowage was repaired after the 2009 fish kill. The DNR said it saved enough fish to allow for a rebuilding of the populations.
The fish kill is sudden and bad news for area anglers. It comes just a few weeks after the World Ice Fishing Championship was held on Big Eau Pleine.