Obviously, the summer boating season has come to an end as has the boating traffic except for the “Here fishy, fishy” crazies dropping anchor in Flathead Lake in pursuit of the big one and slice of the up to $200,000 payout in cash and prizes for hooking tagged lake trout in the Fall Mack Days however that will end this Sunday. And that will put to rest for another boating season and the white-knuckle concern about the potential for infestation of zebra and/or quagga mussels in Flathead Lake, the Flathead River and Upper Columbia River basins that by linkage are part of the Columbia River Basin. The Columbia River Basin is the only river basin in the contiguous United States not infested by the invasive zebra and/or quagga mussels.
The Columbia River Basin covers nearly 260,000 square miles. It includes the Upper Columbia headwaters that consists of river and stream flows from western Montana and southeastern British Columbia that flow into and through Idaho, Washington and Oregon. The Columbia River pours more water into the Pacific Ocean than any other river in North or South America. It is a vital component of states, communities, economies and industries that rely on the Columbia River Basin for benefits such as low cost and reliable hydro-electricity, flood control, irrigation, navigation, recreation and fisheries. The ecology of the entire Columbia River Basin and its related economy production are at risk due to the threat of an infestation of aquatic invasive species (AIS) zebra and quagga mussels.
AIS can: outcompete and displace native species; cause dramatic shifts in trophic dynamics, food web structure, and species abundance; cause local extinction of species; cause large-scale mortality of trees and shrubs; reduce the value of timber and agricultural crops and their associated products; alter ecosystem processes; modify the provision of ecosystem services; alter gene pools through hybridization with native species; alter carbon and nitrogen cycling, water use, and soil properties; reduce potential of recreationally hunted and fished species; diminish habitat aesthetics; and, alter water chemistry.
According to the 2018 report, prepared by the Montana Department of Natural Resources and Conservation in cahoots with the Montana Invasive Species Council, the Flathead Lake Bio Station and the National Invasive Species Council, a quagga and/or zebra mussel invasion would cost Montana an estimated $234 million per year in damages to the state economy. The $234 million ding would be on the recreation and agriculture sectors as well hydro-related infrastructure damage and government revenue.
Out compete and displace native species is what the non-native Mackinaw lake trout have done to Flathead Lake, thus the semi-annual CSKT Mack Day. However, the damage done to the Flathead Lake ecology by Mackinaw trout pales in comparison to what would happen with an infestation of the zebra and/or quagga mussels. That is why the Montana Fish, Wildlife and Parks AIS Bureau in conjunction with other governmental partners such as the Flathead Nation and private entities vigilance is of mega-importance in the prevention of a zebra and/or quagga mussel infestation.
The invasive mussels aren’t strangers to Montana. They were detected in the Missouri River Basin in 2016 in larvae veligers, from either invasive zebra or quagga mussels during water sampling at Tiber. A suspected positive sample was also detected at Canyon Ferry Reservoir that same year. Vigilant water sampling for three years in Canyon Ferry Reservoir resulted in its delisting as a mussel-positive water body in 2019; five years of water sampling in Tiber Reservoir resulted in its delisting in 2021.
Ominously, the invasive mussel threat is getting closer to home as this July when South Dakota officials confirmed that zebra mussels were detected in Pactola Reservoir near Rapid City. The discovery brings zebra mussels within 75 miles of Montana. Montana watercraft inspection stations see approximately 50 boats from Pactola Reservoir every year.
For those reasons the importance of the FWP watercraft inspection stations at strategic locations on Montana highways cannot be overstated. The Flathead Nation, in partnership with FWP operates two of them, one at Thompson Falls and the other at Ravalli. And they have been an important part of the AIS prevention phalanx in the state.
According to the final 2022 statistics posted by the FWP AIS Bureau there have been 53 mussel fouled watercrafts detected among the 98,832 inspections conducted that included 19,194 high-risk watercrafts from states with known zebra and/or quagga mussel AIS infestations. The high-risk watercraft largely emanate from Midwest states that border the Great Lakes and the Southwest. Last year a record of 61 mussel-fouled watercraft were intercepted during 123,311 inspections and not breaking that record is a good outcome this year.
At the Ravalli inspection station, a total of 13,706 inspections have been conducted with one mussel-fouled boat detected. The inspected watercrafts included 2,913 from high-risk states. It intercepted one mussel-fouled boat in May, and another in August. The Ravalli station is the second busiest inspection station in the state.
The Thompson Falls inspection station has conducted 4,085 inspections that included 138 high-risk watercrafts; no mussels were detected.
The Clearwater inspection station continues to be the station that conducts the most inspections. To this point in time the station has conducted 30,679 inspections that included 2,718 high-risk watercrafts. It intercepted two mussel fouled watercraft in early May.
AIS prevention is a never ending battle. Now with the winter weather comes the planning for next year.