The Michigan Department of Natural Resources says this is the time of year when people report fish kills in lakes around the state.
DNR fisheries biologist Jeremiah Blauw tells us fish kills happen in the winter when reduced sunlight underwater leads to plants dying off. That, in turn, leads to less oxygen in the water, which can kill fish.
“A lot of these shallower lakes and ponds during the winter, as the winter progresses, we’ll see that sunlight diminish as well as the ice thickness increase,” Blauw said. “We actually have the aquatic vegetation dying and that consumes the oxygen in the water.”
The fish that might wash up along the shore this time of year actually died months ago. Blauw says the sight of them can lead people to think there’s something wrong with the water, but it’s usually a normal event. However, the DNR does want people to report fish kills through its Eyes in the Field Reporting System.
“You say your lake, your area, what fish you’re observing, and then that gets into a central database, and then I actually receive that email as soon as an individual reports that fish kill.”
Fortunately this year, Blauw says there may be fewer fish kills because this winter didn’t provide much ice cover on lakes.
Fish kills are more common in smaller lakes and ponds, and not so much the Great Lakes.
You can learn more at Michigan.gov/Fishing.
