Vigilant Inspection Methods Preserve Flathead Lake’s Mussel-Free Waters
Local, state, tribal and federal agencies detected and prevented 42 mussel-infested boats from entering the Flathead watershed through over 100,000 boat inspections in 2024
By Zoë Buhrmaster
The Flathead Lake Biological Station (FLBS) celebrated another successful year of evading an infestation of aquatic invasive species (AIS) in local waters, crediting early and aggressive inspection methods which prevented 42 mussel-infested watercrafts from entering the Flathead watershed.
Local, state, tribal and federal agencies conducted over 100,000 boat inspections in 2024, according to the 2024 aquatic invasive species (AIS) program report. Inspections are the eight-year-old program’s first line of defense against boats coming in from states with known infestations, AIS specialist Phil Matson noted in the report.
“With the limited daylight offered to inspectors on the highways, boats can slip past inspections after hours,” Matson stated. “A strong presence must be felt at the moment before a boat launches into a waterbody, so having someone on site to check the boat’s status is critical to preventing that one boat from spoiling it for us all.”
Zebra and quagga mussels are two pinnacle invasive species the AIS program has its eye on, particularly as both variants have been discovered in recent years in Idaho’s Snake River, South Dakota’s Pactola Reservoir, and Colorado’s Highline Lake. Mussels can be highly deleterious to an ecosystem by smothering native species’ food resources and resulting in toxic algae blooms, along with clogging lake infrastructure. Once present, mussel removal becomes an uphill battle as the process is time consuming and expensive.
The AIS team took three rounds of samples for zebra and quagga mussels at 31 sample sites on Flathead Lake and other lakes in the basin, including Swan Lake, Ashley Lake, Echo Lake, Little Bitterroot Lake, Lake Mary Ronan, and Hungry Horse Reservoir. All came back negative.
This year the FLBS also introduced a new rapid detection technology called loop-mediated isothermal amplification (LAMP), which biologists launched during a two-day training for pertinent agencies in the Flathead watershed. With LAMP, the AIS team can determine whether a site is infested in as quick as 30 minutes without having to leave the site, a dramatic improvement compared to the previous standard of taking the samples offsite and waiting weeks for results.
“We had a lot of promising things coming out of the 2024 field season and I am excited to see them built upon next year,” according to Matson. “Rapid detection technology is advancing and gaining traction, the Western Montana Conservation Commission is setting up its AIS committee to bolster regional prevention efforts, and keen focus is being placed on all available tools as neighboring states come to grip with the reality of invasive mussels in the region.”