Montana FWP Finds a Nonviable Invasive Mussel Larva in Whitefish Lake; Follow-Up Tests Negative

Montana Fish, Wildlife & Parks (FWP) says it found a single nonviable invasive mussel larva, called a veliger, in a water sample from Whitefish Lake. The agency's AIS Early Detection Laboratory flagged it on Oct. 21.

Follow-up genetic testing on the organism found no mussel DNA. FWP crews then collected and tested more lake samples and sent in a dive team to look for live mussels, and all of that work came back negative. More microscopy and eDNA sampling will continue.

"While the negative results are encouraging, they do not definitively rule out the presence of invasive mussels in the lake," said Tom Woolf, FWP's aquatic invasive species supervisor. The agency is working with the City of Whitefish and the Whitefish Lake Institute to increase monitoring under its mussel response plan.

FWP noted that zebra and quagga mussels have been showing up closer to Montana, including in Idaho's Snake River and the lower Missouri River in North Dakota. The Missoulian reports it is Montana's first detection of this kind in about a decade. Boaters are asked to clean, drain and dry their boats every time and to stop at all required watercraft inspection stations.

This is a The Gillnet news desk summary, not a reprint.

Source: Montana FWP: Nonviable mussel larva found in Whitefish Lake (Oct. 30, 2026). Additional reporting: Missoulian.