The Minnesota Department of Natural Resources has confirmed zebra mussels and zebra mussel larvae in Cedar Lake, near New Prague in Scott County, and Big Marine Lake, near Forest Lake in Washington County.

A lake service provider notified the DNR after finding zebra mussels attached to a dock on Cedar Lake. A contract diver found no adult zebra mussels in Cedar Lake, but water samples analyzed by the DNR contained zebra mussel larvae, called veligers.

DNR and conservation district watercraft inspection staff found adult zebra mussels on two watercraft exiting Big Marine Lake at different locations. No adult zebra mussels were found during subsequent dive searches, but water samples analyzed by the DNR contained veligers.

Although additional adult zebra mussels were not found in these lakes during follow-up searches, the presence of veligers suggests reproducing zebra mussel populations. For that reason, these lakes will be listed as infested for zebra mussels.

Whether or not a lake has any invasive species, Minnesota law also 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 (mndnr.gov/decon).
• 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 (mndnr.gov/invasives/ais/contacts.html) 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 (mndnr.gov/ais).