DETROIT LAKES, Minn. — Freezing cold, high winds and tons of snow made this past winter miserable for humans, but fish in lakes across the region may have had it even worse.
Severe winters kill off fish, says Minnesota Department of Natural Resources fisheries supervisor Nathan Olson, and that could mean fewer bites out on the lakes.
It’s called winterkill. When snow and ice pile up on lakes, it blocks sunlight from reaching vegetation at the bottom. When the vegetation dies and decomposes it releases bacteria that use up oxygen in the water.
With less oxygen, more fish die off.
“Most of the time it’s the shallower lakes that have maybe more plant growth — there are more plants that can die and decompose under the ice,” Olson explained.
This winter checked off all the boxes for a major winterkill event, which means anglers might be in for a slow season.
But Olson says all hope is not yet lost.
“It can impact fishing, but for some lakes it can be really good because it’s sort of a reset button for a lot of these fisheries,” he said. “Getting a winterkill is actually a good start over point it can get rid of a lot of nuisance fish species — we’ve seen some really good growth rates in fish after a winterkill.”
All the signs of a big winterkill are there, but the Minnesota DNR won’t be certain about how severe it is until all the ice is off the lakes .
The DNR asks that if you see a large number of dead fish to give your local office a call. It will help them hone in on the areas with the most winterkill