Zebra mussels confirmed in lakes in Crow Wing, Itasca counties

The Minnesota Department of Natural Resources has confirmed zebra mussels in Serpent Lake in Crow Wing County, and in Dora Lake and connected waters in Itasca County. 

A lake service provider business removing a dock from Serpent Lake contacted the DNR after finding several suspected zebra mussels. DNR invasive species specialists confirmed zebra mussels attached to vegetation hanging from a removed dock at a second location, at the Highway 6/210 public access, approximately 1.3 miles away from the originally reported location.

Itasca County aquatic invasive species staff found zebra mussels downstream of Sand Lake, where zebra mussels were confirmed in 2013. The DNR confirmed zebra mussels at the Shogren Dam; Dora Lake, a small, shallow lake downstream of Sand Lake; and in the Big Fork River, seven miles downstream from Dora Lake at the Itasca County Road 31 crossing near Wirt.

Fall is an important time to check for zebra mussels, when docks and boat lifts are being removed from lakes at the end of the season. Look on the posts, wheels and underwater support bars of docks and lifts, as well as any parts of watercraft or equipment that may have been submerged in water for an extended period.

Minnesota law requires that docks and lifts be allowed to dry for at least 21 days before being placed in another body of water, whether aquatic invasive species are present or not.

Whether or not a lake is listed as infested, Minnesota law requires boaters and anglers to:

  • Clean watercraft of aquatic plants and prohibited invasive species.
  •  Drain all water by removing drain plugs and keeping them out during transport.
  • Dispose of unwanted bait in the trash.

Some invasive species are small and difficult to see at the access. To remove or kill them, take one or more of the following precautions before moving to another waterbody, especially after leaving infested waters:

  • Spray with high-pressure water.
  • Rinse with very hot water (120 degrees Fahrenheit for at least two minutes or 140 degrees Fahrenheit for at least 10 seconds).
  • Dry for at least five days.

Zebra mussels can compete with native species for food and habitat, cut the feet of swimmers, reduce the performance of boat motors, and cause expensive damage to water intake pipes.

Contact an area DNR aquatic invasive species specialist if you think you have found zebra mussels or any other invasive species that the DNR has not already confirmed in your lake.

More information is available at mndnr.gov/ais.