Nonviable mussel larva found in Whitefish Lake

KALISPELL– Montana Fish, Wildlife & Parks detected a nonviable invasive mussel larva in Whitefish Lake in a water sample last week. Additional samples collected from the lake have since tested negative for the presence of live mussels.

A single nonviable invasive mussel larva, called a veliger, was detected by FWP AIS Early Detection Laboratory on Oct. 21. The organism was sent for follow up testing, which detected no evidence of mussel DNA. AIS staff collected and tested more samples from the lake and deployed a dive team to conduct a survey to look for live mussels. The extensive follow up sampling is negative for the presence of live mussels; additional 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 AIS Supervisor. "With a detection like this, sometimes no other evidence is ever found. We will continue to evaluate the initial finding and work with partners, including the City of Whitefish and Whitefish Lake Institute, to step up our sampling and monitoring of the lake in accordance with our mussel response plan."

Invasive mussels, including zebra and quagga mussels, pose a significant threat to Montana’s waterways. They can reproduce rapidly, clog water infrastructure, and disrupt aquatic ecosystems. Preventing their spread remains a priority. In recent years, invasive mussels are showing up closer to Montana’s borders, particularly in the Snake River in Idaho and the lower Missouri River in North Dakota.

"We can’t let up. We have to protect our waters by following clean, drain, dry practices every time we come off the water," said Woolf. "All watercraft should be cleaned, drained, and dried before being moved between waterbodies, and boaters should stop at required watercraft inspection stations."

More information will be shared as it becomes available.