Lake Michigan sees larger than normal fish kill, "something we have not seen in years": DNR

Alewife die-off
Alewife are experiencing a seasonal die-off in Lake Michigan, extending from Muskegon all the way up to Cross Village and out to the Beaver Island complex. Photo credit Michigan Department of Natural Resources

(WWJ) Visitors to the Lake Michigan shoreline should be not alarmed by an abundance of small, dead fish on the beach, state wildlife experts say.

The Michigan Department of Natural Resources says alewife — prey fish that measure only 2 to 9 inches long — are experiencing a seasonal die-off in Lake Michigan; an event that frequently occurred 20 to 60 years ago but has been rare in recent times.

The DNR said in a news release Wednesday that it's "fully aware" of the situation, and believes this is a natural event and not caused by pollution or disease

“The die-off is larger than normal this year and something we have not seen in years,” said Jay Wesley, Lake Michigan basin coordinator for the DNR. “We are seeing the die-off extend from Muskegon all the way up to Cross Village and out to the Beaver Island complex.”

While perhaps not a cause for concern in an official sense, the unpleasant presence of these dead fish in large quantities has been keeping visitors off typically popular beaches from Petoskey to Boyne.

Not native to the Great Lakes, alewife migrated from the Atlantic Ocean into the Great Lakes through the Welland Canal in the 1920s, the DNR says.

Alewife spend most of the year in deep, cold waters. In the spring and summer, they migrate to nearshore areas to spawn and search for food. Some alewife come out of winter in a weakened state and don’t tolerate changing conditions such as large temperature swings. The combination of poor over-winter condition, temperature changes and spawning stress cause the die-off.

Both state and federal agencies annually collect alewife to evaluate their condition and abundance in Lake Michigan.

For more information on die-offs (also known as fish kills) in Michigan, visit Michigan.gov/FishHealth. The public can report fish kills at Michigan.gov/EyesInTheField.

If you suspect a fish kill is due to non-natural causes, call the nearest DNR office or Michigan's Pollution Emergency Alert System at 800-292-4706.