The invasive aquatic plant called European frogbit was found in Oceana and Ottawa counties this summer.
Frogbit is a small green plant that looks like a water lily. Kevin Walters with the Michigan Department of Environment, Great Lakes and Energy said it can form dense mats on the water's surface.
"So there’s no light penetration in the water, it makes movement of waterfowl and fish difficult," Walters said. "For humans it makes access to the water for fishing, swimming, boating, things like that can become very difficult."
Boaters should clean, dry and drain their boats to prevent spreading European frogbit, he said.
European frogbit has been in Michigan waters since 1996 and has spread to coastal areas of Lakes Erie and Huron.
The aquatic plate was confirmed on Pentwater Lake in Oceana County on Aug. 21.