The Minnesota Department of Natural Resources has confirmed the presence of zebra mussels in Roosevelt Lake, near Outing in Cass and Crow Wing counties, and Swan Lake, near Pengilly in Itasca County.
A surveyor hired by the Roosevelt and Lawrence Area Lakes Association found three adult zebra mussels at the Roosevelt Lake public water access. They notified the DNR, and DNR staff found additional adult zebra mussels at the public water accesses and throughout the lake in follow-up surveys.
Itasca County invasive species staff contacted the DNR after juvenile zebra mussels were found attached to settlement samplers in Swan Lake. Settlement samplers are solid surfaces temporarily placed in the water that people can regularly check for zebra mussels to aid in detection. The Swan Lake Association deployed the settlement samplers as part of its prevention and early detection efforts. DNR invasive species staff confirmed the presence of zebra mussels at multiple locations in Swan Lake.
Whether or not a lake has any invasive species, Minnesota law requires people to:
- Clean watercraft, trailers and equipment to remove aquatic plants and prohibited invasive species.
- Drain all water and leave drain plugs out during transport.
- Dispose of unwanted bait in the trash.
- Never release bait, plants or aquarium pets into Minnesota waters.
- Dry docks, lifts and rafts for 21 days before moving them from one waterbody to another.
These additional steps reduce the risk of spreading aquatic invasive species:
- Decontaminate watercraft and equipment – find free stations on the courtesy decontamination page of the DNR website.
- Spray watercraft and equipment with high-pressure water or rinse with water if high-pressure water is not available.
- Dry watercraft and equipment for at least five days before using in another waterbody.
People should contact a Minnesota DNR aquatic invasive species specialist if they think they have found zebra mussels or any other invasive species that was not already known to be in the waterbody.
More information is available on the aquatic invasive species page of the DNR website.