News release: Faucet snails confirmed in George Lake in Mahnomen County

June 30, 2022

The Minnesota Department of Natural Resources has confirmed a report of faucet snails in George Lake, located entirely within the White Earth Reservation in Mahnomen County.

A White Earth Nation official who is also a member of the State Aquatic Invasive Species Advisory Committee, Will Bement, contacted the DNR with faucet snail samples collected by a bait harvester trapping leeches on George Lake. A DNR research scientist confirmed that the samples were faucet snails.

Faucet snails are much less prevalent than zebra mussels in Minnesota and they have very different impacts on habitats. While ingesting them is not harmful to humans, faucet snails can be fatal to waterfowl. The snail is an intermediate host for three intestinal trematodes, or flukes, that can cause mortality in ducks and coots. When waterfowl consume the infested snails, the adult trematodes attack the internal organs and cause lesions and hemorrhage. The trematodes contributed to the deaths of about 9,000 scaup and coots in 2007 and 2008 on Lake Winnibigoshish, where faucet snails were first confirmed in inland Minnesota waters.

Faucet snails also compete with native snails for food and habitat. They may clog water intake pipes and other submerged equipment. Currently, there is no known effective population control for faucet snails in natural water bodies.

Faucet snails are small animals with coiled spiral shells. They grow up to a half inch long and are longer than they are wide. They are light brown to black, with four to five coils (whorls) on the shell. Faucet snails can be difficult for non-specialists to identify conclusively, as they look similar to native snail species found in Minnesota.

People spread faucet snails primarily through the movement of water-related equipment. The snails can attach to boats, docks, swim rafts and boat lifts, as well as scuba, fishing and hunting gear. Faucet snails can close their shells and survive out of water for multiple days.

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 water body 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 with high-pressure water or rinse with very hot water (120 degrees for at least two minutes or 140 degrees for at least 10 seconds).
  • Dry watercraft and equipment for at least five days before using in another water body.

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 on the aquatic invasive species page of the DNR website.