Zebra mussels confirmed in Bde Maka Ska

Posted on 8 October, 2018

The Minnesota Department of Natural Resources (DNR) has confirmed a report of zebra mussels in Bde Maka Ska. Zebra mussels were confirmed in Lake Harriet, immediately downstream of Bde Maka Ska, in September of 2017.

A Minneapolis Park and Recreation Board (MPRB) watercraft inspector contacted the DNR after finding two juvenile zebra mussels on a sailboat as it was being removed from Bde Maka Ska for the season. Staff from the DNR, MPRB, Minnehaha Creek Watershed District, Blue Water Science and Waterfront Restoration are inspecting the lake to determine the extent and distribution of the zebra mussel population.

Staff are also utilizing cutting-edge eDNA sampling, in which filtered water samples are sent to a lab to search for traces of zebra mussels. This will also help determine the extent and distribution of the infestation.

Because the sailboat had been moored in the lake for an extended period and the young zebra mussels indicate in-lake reproduction, treatment would likely not be effective. Early detection is still important, because it can help prevent spread to other lakes. MPRB is inspecting all sailboats being removed from the lake. Zebra mussels have not been reported on any additional boats.

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

  • Clean watercraft and trailers of aquatic plants and prohibited invasive species,
  • Drain all water by removing drain plugs and keeping them out during transport, and
  • 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:   

  • Spray with high-pressure water.
  • Rinse with very hot water (120 degrees F for at least two minutes or 140 degrees F 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.

People should contact an area DNR aquatic invasive species specialist if they think they have found zebra mussels or any other invasive species.

More information is available at mndnr.gov/ais.