Longterm Ice Cover Responsible for Fish Kills in Area Lakes
Posted
Jordan Fouts-
WINONA LAKE – The long, cold winter is responsible for numerous fish kills in area lakes, water and wildlife experts say. Hundreds of dead gizzard shad have washed up on the banks of Pike Lake, Robert Schultz, a longtime fisherman in the county, told WSBT. The species is less tolerant of freezing temperatures, according to the Department of Natural Resources, which has received reports of fish kills at other lakes. Nate Bosch, director of the Center for Lakes and Streams at Grace College, said this morning he was previously aware of fish kills at Winona Lake and in bodies of water in the southern part of the county. He said it’s likely that other species of fish will be found floating on the surface or washed ashore as the ice cover continues to retreat. “The temperature in the water probably wasn’t any colder than in the past. The temperature is pretty consistent from year to year,” he said, attributing the deaths mainly to loss of oxygen in the water over the course of winter. Long-term ice cover under heavy snow shuts the lake off from sunlight, he said, preventing aquatic plants like algae from growing and keeping oxygen levels up. The longer the ice cover lasts, the more oxygen gets used up, eventually causing fish to suffocate. He said oxygen levels will build back up almost immediately once the lake surface clears, as wind blowing over the water causes oxygen to mix into it again. In the meantime, he said the lakes center and IDNR will continue to monitor fish kills as more ice melts on county lakes.
