ST. PAUL — Since confirming zebra mussel larvae in Red Lake earlier this year, the Minnesota Department of Natural Resources and the Red Lake Band Department of Natural Resources have conducted additional plankton surveys in Upper and Lower Red Lake, a release said.

In 2019, 105 samples from 10 sites were collected by Red Lake tribal biologists and processed by the Minnesota DNR. Four samples contained zebra mussel larvae, called veligers -- two from Upper Red Lake and two from Lower Red Lake. Zebra mussel veliger numbers ranged from one to six per sample, the release said.

Repeated occurrences of multiple veligers strongly suggest zebra mussel reproduction is occurring in the lake. There is no viable explanation for seeing multiple veligers in two different sites in both Lower and Upper Red Lake other than an established zebra mussel population.

No adult zebra mussels have been confirmed in Red Lake, the release said. They may be very difficult to find, given the large size of the lake. The Minnesota DNR has observed a similar situation in Leech Lake. Some veligers were found in water samples over several seasons, with adult zebra mussels only recently being reported by Minnesota DNR fisheries specialists.

The Minnesota DNR will be coordinating closely with the Red Lake Band to develop a comprehensive and aggressive response to these most recent findings. This work will also include a focus on preventing introductions of other aquatic invasive species.

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Red Lake natural resources staff have conducted water sampling on Red Lake and several other lakes since 2012.

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.

  • 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 for at least two minutes or 140 degrees 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 extensive damage to water intake pipes.

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

More information is available at