Fish kill expected on Big Eau Pleine Reservoir

MOSINEE (AP) - State biologists expect a spring fish kill on the Big Eau Pleine reservoir in central Wisconsin to be even bigger than one four years ago, when tens of thousands of fish died.

Judging from reports by area ice anglers, the fish kill may have already started, according to the Wisconsin Department of Natural Resources.

Oxygen levels in the Eau Pleine are so low fish can't breathe, the DNR said. Nutrient-rich sediment and organic material decays and sucks the oxygen out of the water and the ice limits air and light from replenishing it.

After the 2009 fish kill, state and local officials repaired and improved an aerator to boost oxygen levels in the reservoir, the Marshfield News-Herald reported.

"In 2009, the aeration system did provide some refuge to the fish, and although the fish kill was severe, later surveys showed a surviving fish population capable of rebuilding the fishery," said Tom Meronek, DNR fisheries biologist. "But the fish kill could be more severe in 2013, because we are seeing much lower dissolved oxygen levels in the reservoir upstream from Highway S than those recorded in 2009."

A large fish kill could spell trouble for local business owners who rely on revenue from fishing. Debbie Hotchkiss owns the Hotchkiss Last Cast bar and grill.

"It will be huge for us, like it was three or four years ago. We'll lose business. It's not good." Hotchkiss said.

The World Ice Fishing Championship was held on the 7,000-acre reservoir last month.