PLYMOUTH, Minn. (KMSP) - The Minnesota Department of Natural Resources has confirmed zebra mussels in Medicine Lake in Plymouth. A lakeshore property owner notified the DNR and Three Rivers Park District staff when a worker discovered one adult zebra mussel on a dock they were removing from the lake.
DNR invasive species staff confirmed two more adult zebra mussels attached to docks at separate locations, indicating a lake-wide presence. The DNR said this confirmation is disappointing after six previous reports of zebra mussels on Medicine Lake turned out to be negative.
The fall season is an important time to check for zebra mussels, as docks and boat lifts are removed from lakes. Check 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.
To remove or kill invasive species, take one or more of the following precautions before moving to another body of water:
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 are a threat to healthy, native species as they can compete for food and habitat. They are also a hazard to swimmers and watercraft as their shells can cut the feet of swimmers, reduce the performance of boat motors and cause expensive damage to water intake pipes.
If you think you have found a zebra mussel in your lake, contact the Minnesota DNR.