As the ice melts, you might see dead fish in Michigan’s shallow lakes and streams.
The state Department of Natural Resources says the “winterkill” is natural as lower oxygen levels in water during the winter takes its toll on marine life.
Gary Whelan is the Fisheries Division program manager. He says the winterkills typically don’t drastically affect fish populations.
“It varies a tremendous amount. It could be as high as 20 or 50% in some lakes. In other lakes, it may be just 5% because it’s a small cove that’s affected.”
Nitrogen and phosphorus from nutrient runoff can contribute to making fish kills happen more often.
That’s because they help spur excess vegetation growth in the water. Eventually oxygen levels can get too low in the water and fish can die.