Why Are Dead Fish Floating, Washing Ashore On Twin Cities Lakes?

MINNEAPOLIS (WCCO) – An unsightly phenomenon is happening in some Twin Cities lakes. You may have seen or smelled dead fish floating or washing ashore. The DNR says it's fish kill.

It's happening at Crystal Lake in Burnsville as well as Cedar Lake and Lake Harriet in Minneapolis. It happens every year, but it's typically in August.

"I've more smelled it than I've seen it," Chuck Marchall said.

The stinky sight is getting people's attention around the lake.

"I walk around here almost every day. I saw hundreds if not thousands of panfish that were dead," Jack Swan said.

They even caught the eye of swimmers. Dead fish continued to float right up to where kids were splashing in the water.

"The first one was kind of like, 'Why is it there?' and then I realized it's all over the place, so it seemed like there must be something bigger going on," mom Rachel O'Banion said.

There is. It's something the DNR calls fish kill. It typically happens when it's hot and after a lot of rain, where nutrient runoff enters a lake.

"One of the most common is low levels of oxygen in the lake and it just really stresses the fish out," said Debra Pilger, with Minneapolis Park and Recreation Board.

It can also happen during spawning and from bacteria. The Minneapolis Park and Recreation Board is monitoring the situation at Lake Harriet and Cedar Lake.

"Right now the numbers are such, the species are such, we've been reporting it to the DNR, we're not at a really high level of concern," Pilger said.

So, O'Banion keeps scooping the fish up away from her kids.

"Occasionally they'll ask me to pick one up and get it over to the side," O'Banion said.

While others find the silver-lining.

"The good news is I think we get to see more eagles because they come down and grab those stinky fish," Kari Kramer said.

In 2018, 28 lakes experienced fish kill in July and August. In Minneapolis, Park Board staff members clean up the fish when they see them. You can also alert them to an area by calling 612-230-6400.