The Minnesota Department of Natural Resources confirmed a report of zebra mussels in Mahnomen Lake, East Mahnomen Lake and Upper South Long Lake in Crow Wing County.

A landowner reported finding zebra mussels on equipment in front of their property on Mahnomen Lake. A DNR invasive species specialist immediately found numerous and abundant adult zebra mussels on a dock post.

On Upper South Long Lake, a lake service provider business informed a landowner they may have found zebra mussels on dock equipment when removing it for the season. The landowner contacted the lake association, who reported it to the DNR. A DNR invasive species specialist found adult zebra mussels on dock equipment at the site of the initial report and on dock equipment on the opposite shore of the lake.

In May, the DNR confirmed a report of zebra mussels in South Long Lake, upstream of but connected to Upper South Long Lake. Five hundred feet of the Nokasippi River upstream and downstream of South Long Lake were also listed for zebra mussels at that time.

“It’s very helpful when lake service provider businesses, lake property owners and lake associations work together when they suspect invasive species in a lake,” said Heidi Wolf, DNR invasive species unit supervisor, in a news release. “They all play an important role in detecting invasive species, by carefully examining boats, docks and lifts when they are being removed from the water at the end of the season.”

Newsletter signup for email alerts

As a reminder, Minnesota law requires docks and lifts remain out of the water for at least 21 days after removal from a waterbody before they can be placed into another waterbody. In addition, anyone who transports a dock or lift from a shoreline property to an off-site location for storage or repair may need a permit to help prevent the spread of aquatic invasive species.

There are important prevention considerations for lake property owners:

  • Look on the posts, wheels and underwater support bars of docks and lifts, as well as any parts of boats, pontoons and rafts that may have been submerged in water for an extended period.

  • Anyone paid to remove boats, docks, lifts and other water-related equipment must be DNR trained and permitted. A list of DNR-permitted lake service provider businesses is available on the DNR website.

  • Contact an area DNR aquatic invasive species specialist if an invasive species is discovered in a waterbody that has not already been confirmed in that water.

More information is available at mndnr.gov/AIS.