News & Features

Preliminary Results: No New Detections of Invasive Mussels in Montana

Water sample results indicate mussels isolated to Missouri River Basin

Preliminary results of water samples from across Montana indicate invasive mussels have not infested other water bodies beyond the Missouri River Basin, according to a statewide interagency strike team.

Jeni Flatow, public information officer for the Montana Mussel Incident Response Team, said lab results from 372 samples show no new detections of aquatic invasive mussels in lakes or rivers across the state, including the Flathead basin.

Flatow said the results are being finalized and will be formally announced in the coming days, but the overarching detail is that “there are no other positive hits” of mussel infestations in Montana. The samples were gathered across the state in mid to late summer.

The preliminary results provide a large sense of relief following the first detection of invasive mussels in Montana earlier this year in Tiber and Canyon Ferry reservoirs. In the wake of the detection, the state has formed a task force handling the situation, including expediting water sample testing, with the goal of combating the spread of the harmful mussels.

Following the detection in Tiber and Canyon Ferry, ongoing sampling and testing found “suspect” samples in the Milk River downstream of Nelson Reservoir, and the Missouri River upstream from Townsend. The two reservoirs were closed to boats in early December.

The miniscule mussels, which cling to boats and other watercraft and can colonize rapidly, threaten ecological and economic consequences.