The ice is finally off area lakes, but in some cases it has left behind dead fish on the shorelines. A combination of lower water levels, early and abundant snowfall, and the late ice-out date, winterkill has been severe this spring at Lake Emily near Hancock.
When snow and ice cover a lake, they limit the sunlight reaching aquatic plants. The plants die from lack of sunlight, stop producing oxygen, and then decompose - a process that also consumes oxygen. This oxygen deficit can kill fish.
Dean Beck, DNR Area Fisheries Supervisor, said his staff were on the lake Tuesday. They found representatives of most fish populations washed up on shore. Gamefish included a few large walleye, crappie, white bass, and channel catfish. Freshwater drum or sheepshead and the limited population of channel catfish comprised most of the dead fish. He said both species are common to river systems and thus are not very tolerant of water with low dissolved oxygen concentrations.
"There is good news," said Beck. "The guys caught healthy walleye, crappie, northern pike, and yellow perch while on the lake."
Beck said the winterkill on Emily can be classified as a "partial" fish kill. Some gamefish were lost, but all common species continue to reside in the lake.
"The adults will reproduce this spring to fill the void."
Walleye were already scheduled to be stocked. That stocking will occur in May.
"Anglers may face fewer harvestable fish, but the fishery will rebound quickly," said Beck. "Loss of white bass may prove to be a positive event since this species is a predator that would be competing with walleye and northern pike."