Invasive snails found at state fish hatchery

Contamination will cost state nearly $225,000

HELENA, MONT. — Invasive New Zealand mud snails have been discovered  at Montana Fish, Wildlife & Park’s Bluewater State Fish Hatchery near Laurel, Mont.

To eliminate the threat of further spread, most of the rainbow trout and largemouth bass at the facility will be destroyed, according to FWP. The loss of hatchery fish that will have to be destroyed will cost the state about $225,000, FWP said.

The Bluewater fish hatchery in Laurel, Montana, where invasive mud snails were found. Photo courtesy Montana Fish, Wildlife and Parks

New Zealand mud snails. Photo courtesy of the U.S. Geological Society

New Zealand mud snails are an aquatic invasive species found in a variety of waterbodies across Montana. The snails have the ability to expand in population size and in distribution rapidly, potentially changing the ecology of waterbodies where they are located, FWP said. Once established in waterbodies, the mud snails are difficult to eradicate, according to Montana FWP.

The source of the new infestation is unknown, though FWP staff believe cracks in older concrete tanks might have allowed mud snails from the previous infestation to survive decontamination.

Montana FWP is decontaminating the hatchery and its oldest concrete settling basins, where this infestation was discovered, and those will no longer be used, according to Eileen Ryce, FWP fisheries division administrator.

The largemouth bass that will be destroyed are brood stock and large enough to eat. FWP staff will hand out the dead bass to youth under 12 or anyone with a fishing license on April 2, from 9:30 a.m. to noon, and Saturday, 9 a.m. to noon. There is a limit of 5 bass per individual. That hatchery is located at 700 Bluewater Creek Road, Bridger, MT.

People who pick up fish need to make sure to dispose of the entrails and carcasses in the household garbage, not in a waterway or down the drain into a wastewater system. Some rainbow trout at the facility will be stocked as planned. These fish are in an interior part of the hatchery that is not connected with the area where the mud snails were found. No mud snails were found in the interior part of the hatchery.

The Bluewater fish hatchery is named after its water supply, a spring with a distinctive blue color, and 58°F water. Fish from this station are generally stocked in the south, central and eastern sections of Montna. Arlee, Eagle Lake and Erwin strains of rainbow trout, Yellowstone cutthroat and grayling are reared annually at the Bluewater fish hatchery.