Zebra mussels infest Crooked Lake in N Minn.

The state Department of Natural Resources is declaring another lake in Minnesota infested with invasive zebra mussels.

Biologists from the Fond du Lac Band of Chippewa found zebra mussels on an aluminum can in Crooked Lake in Lake County, DNR officials said today. Further searches of the lake found more zebra mussels.

Map: Aquatic invasive species spread across Minn.

Zebra mussels hitchhike from lake to lake on boats and trailers. They can clog water intakes and boat motors, leave sharp shells on beaches, and in high numbers can alter the food chain.

Once a lake is designated as infested, officials will post more signs means more signs for boaters at the lake and warnings about downstream waters. The most common methods to prevent the spread of zebra mussels include boat and trailer inspections at public access points and in some places pressure sprayers to wash off any invasives.

The DNR has designated dozens of lakes, rivers and creeks as infested with zebra mussels.