New Zealand mudsnails were detected at Montana Fish, Wildlife & Parks’ Bluewater Fish Hatchery on Tuesday, Aug. 18. This is the first time FWP has detected mudsnails in a state fish hatchery.

The Bluewater Fish Hatchery, located near Bridger in southcentral Montana, is a trout hatchery and is the third largest production facility in the state. Its primary purpose is stocking sport fish into urban ponds, reservoirs and other public waters.

New Zealand mudsnails are an aquatic invasive species. It was first discovered in Montana in 1995 in the Madison River above Hebgen Lake Reservoir. Since then, New Zealand mudsnails have been detected in several major river drainages across the State.

All hatcheries in Montana are inspected annually for AIS and fish pathogens. The mudsnails at Bluewater Fish Hatchery were detected during the hatchery’s annual inspection.

Because of the detection, no fish will leave or be received at the Bluewater hatchery until further analysis and an investigation is complete. FWP staff are working on a containment and mitigation strategy. Testing results will be available next week to help determine the full extent of the infestation.

FWP will be looking at where the hatchery’s fish have been stocked this year and investigate whether the stocking has spread New Zealand mudsnails to any state waters.

The closest New Zealand mudsnail infestation to the hatchery is Bluewater Creek, which the hatchery drains into.