The Minnesota Department of Natural Resources confirmed a report of a zebra mussel in Woman Lake, near Longville in Cass County.

Girl Lake will also be added to the infested waters list, because it is downstream of and closely connected to Woman Lake.

Last year, a lake property owner reported a single, small zebra mussel attached to a dislodged portion of his dock. No zebra mussels were found during a subsequent DNR snorkel search nor during a practice dive by the Cass County search and rescue team. This summer, two more lake property owners reported finding individual adult zebra mussels. Again, no zebra mussels were found during follow-up searches.

Late last month, a county aquatic invasive species inspector found a juvenile zebra mussel on a pontoon boat being removed from Woman Lake for the season. The Cass County aquatic invasive species specialist subsequently examined the pontoon boat and found one more juvenile mussel attached. As this boat is only used on Woman Lake, the DNR has now confirmed the presence of zebra mussels in the lake.

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“Lake property owners and county staff 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,” said Heidi Wolf, DNR invasive species unit supervisor, in a news release.

Minnesota law requires that 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 body of water. In addition, anyone who transports a dock or lift from a shoreline property to another 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.