Protecting Montana's waterways

Invasive Dreissenid mussels pose one of the biggest threats to Montana’s waterways. Native to the Black and Caspian seas, the introduction of zebra and quagga mussels has given rise to extensive detrimental environmental and economic impacts throughout the United States. These invasive mussels are now found in every major watershed in the contiguous United States, except one. The Columbia River drainage basin, which encompasses most of western Montana, is the last major watershed in the country that has not been invaded by zebra and quagga mussels.

Watercraft inspection stations play a significant role in preventing unwanted invasive mussel introductions.

For example, in 2019 alone, over 20,000 boat inspections were performed at the Clearwater Junction Watercraft Inspection Station (WIS) just south of Seeley Lake, making it the single busiest WIS in the entire state.

Early detection and rapid response can be used to contain the spread of invasive mussels, in a worst case scenario. The Clearwater Resource Council (CRC) monitors the lakes within our watershed for invasive mussel veligers (free swimming larvae) to facilitate swift response measures in the event that mussels are brought into our valley.

In 2019, CRC monitored 39 sites on six lakes within the Clearwater basin. Each of these sites was sampled 5 times throughout the summer, and samples were submitted to a laboratory for microscopy evaluation. We are happy to report that all of the samples came back negative and to the best of our knowledge, the Clearwater basin remains mussel free.

Currently, no effective treatment exists for invasive zebra or quagga mussels. Once invasive mussels invade a watershed, we cannot turn back the clock and eradication is impossible. Therefore, CRC’s AIS strategy emphasizes prevention in order to avoid any scenario that would trigger a rapid response action, especially given the interconnectedness of the Clearwater chain-of-lakes.

While CRC reported no invasive mussel detections in 2019, it is important to highlight the limitations of monitoring both in the Clearwater Valley and statewide. Generally, the number of samples collected as compared to the total volume of water to be sampled, hinders detection efforts.

So what does this all mean for boaters? Vigilance and personal responsibility are key – see our common-sense tips below:

• Do not assume ANY waterbody you launch on is mussel-free.

• Learn how to fully and properly clean/decontaminate your boat and associated equipment (if you need assistance, CRC can help!)

• Ensure your boat is “Cleaned, Drained and Dried” EVERY time you launch on a new waterbody.

• Strive to enter Watercraft Inspection Stations with a boat that has been properly cleaned/drained. Inspectors are often busy. Their primary job is to inspect, rather than to provide boat cleaning services. Moreover, everyone knows that we all occasionally have a bad day, watercraft inspectors included. On such days, key inspection elements may be inadvertently overlooked. While watercraft inspection stations are part of the solution, the AIS prevention program will not be successful without stewardship from the boating community.

• And remember, the watercraft inspectors are serving on the front lines of the AIS prevention effort. Even if you are pressed for time, try to give them a smile and thank them for their service!

If all boaters follow the Clean, Drain, Dry protocols we can avoid future lake closures, decontamination stations upon exit from all lakes, and other more onerous management requirements. Prevention continues to be the best course of action to protect recreational amenities and aquatic resources in the Clearwater Valley.

Thank you all for doing your part to prevent invasive mussels from entering our pristine valley. If you reside in the Seeley Lake region and would like to get involved with our aquatic invasive species monitoring program, contact Emily at the Clearwater Resource Council at emily@crcmt.org or 980-229-3855.