Big Eau Pleine Fish Kill: Not As Bad As It Could Have Been

The Department of Natural Resources (DNR) says the fish kill on central Wisconsin’s Big Eau Pleine reservoir was major, but not as bad as predicted.

Large numbers of dead fish again washed up on the shoreline of the Eau Pleine, a big reservoir on the Wisconsin River south of Mosinee. According to a Department of Natural Resources news release, the fish kill reduced walleye numbers significantly, but could have been worse given the extremely low levels of oxygen in the water.

Credit goes to a rebuilt aerator that provided a refuge. DNR fisheries biologist Tom Meronek says, “The good news for anglers is that … it appears the reservoir can recover” based on the agency’s experience from the last big fish kill in 2009.

But local homeowners are finding little to cheer about, according to John Kennedy of the Big Eau Pleine Citizens Organization.

“The Eau Pleine is on a four year cycle. We had a fish kill in 2005, 2009 and 2013. Something has to change to put a stop to that. The fish population was just starting to come back, and now we’ve been dealt just another severe blow.”

The summer drought led regulators to draw down the reservoir further than usual this past fall. Kennedy wants the practice to stop.

“We’re kind of beating the same drum here, but we need to see an increased amount of water left at ice-up, to provide a buffer to hold more oxygen, to keep the fish through the difficult periods. And that water can still be used, just at a later time.”

A DNR survey of the Eau Pleine showed a catch rate for walleye of only 36 fish per hour, compared to a rate of 144 per hour in the same spot last year.