Montana Aquatic Invasive Species Update: 2024 Wrap Up


Friends and Colleagues,
2024 was another busy year addressing AIS issues across Montana and throughout the region. The 2024 end-of-year reports are attached and will be available on the website soon. Thank you to all the partners around the state who dedicate their time and effort to AIS prevention, early detection and outreach. We are looking forward to a great 2025. A quick summary of 2024 info below:
Prevention:
- Over 135,000 watercraft were inspected in Montana during the 2024 season.
- 47 mussel fouled watercraft were intercepted. More than 800 were found transporting aquatic weeds.
- The Boater Information Gathering (BIG) project interviewed over 1,800 boaters at boat ramps at Fort Peck and Flathead Lake. Less than 3% of the boaters interviewed had not met inspection before launch requirements.
- Watercraft inspection operations in 2025 are anticipated to be similar to 2024.
- Inspection stations begin operation in early March to help address mussel transport on watercraft returning from the lower Colorado River area. Training for watercraft inspection staff begins in February.
- If you are interested in participating in a watercraft inspection training contract Zach Crete: ZCrete@mt.gov
Early Detection:
- Over 3,500 invasive mussel early detection samples collected and processed in 2024 with No invasive mussel detections.
- AIS early detection sampling and survey occurred at over 450 locations state-wide.
- AIS Eradication projects continued at several locations including:
- Eurasian watermilfoil in Beaver Lake near Whitefish: The populations has been reduced from about an acre down to only 7 plants removed in 2024. Follow-up surveys will continue in 2025 to ensure this population is eradicated and does not move into downstream waters.
- Eurasian watermilfoil in Nilan Reservoir near Augusta: This population was reduced from over an acre down to 1 plant removed in 2024. Follow-up surveys will continue in 2025 to ensure this population is eradicated and does not move into lakes and irrigation systems downstream.
- Corbicula clams: No corbiucal clams were found in Lake Elmo in Billings following eradication efforts several years ago. Follow up surveys will continue in 2025.
- If you are interested in hosting an AIS identification / early detection workshop in 2025, please reach out to Craig McLane for more information (cmclane@mt.gov)
AIS Annual Partner Meeting Summary:
Over 60 people attended the Annual AIS Partner meeting on November 13th. The group discussed current AIS issues and operations and strategized ideas for adapting and improving AIS prevention, early detection and outreach moving forward. Some discussion topics included:
- Integrating community based social marketing into outreach campaigns to promote behavior change resulting in boaters and the public normalizing clean, drain and dry for their water-based activities.
- Better utilize the Department of Tourism to target the clean, drain and dry message to boaters coming to Montana.
- Promote the use of reporting apps to expand the involvement of the public in AIS early detection and reporting.
- Recognizing and acknowledging on-the-ground staff for AIS related efforts.
- Identify strategies to improve local enforcement participation at watercraft inspection stations.
In The News:
- Idaho detects invasive quagga mussels again in 2024 and conducts another eradication treatment..
- Golden mussels invade California
- California proposes emergency regulations on Golden Mussels
- US Fish and Wildlife Service’s Risk Screening for Golden Mussels.
- Federal listing of golden mussels
- California closes boat ramps to prevent the introduction of golden mussels
- California’s search for golden mussels identifies another new mussel species in North America: The Axe Head mussel
- Wyoming inspects over 78,000 boats in 2024
- Walleye have higher mercury levels in invasive mussel impacted waters.
- Another lake with zebra mussels in Eastern South Dakota
- Alberta steps up their aquatic invasive species program
- The Western Basin Invasive Mussel Response Toolkit Is now live and online
- The US takes steps to restrict the import of salamanders to prevent the introduction of deadly amphibian diseases
- Western Governor’s Association podcast on addressing invasive mussels
Thomas Woolf | Aquatic Invasive Species Bureau Chief
Fisheries Division
Montana Fish, Wildlife & Parks
Office: (406) 444-1230 | Cell: (406) 438-5305
What you can do to help
- Ensure that you are not part of the problem
- Drain all water from your watercraft before leaving the immediate area of the lake
- Remove all weeds, mud or attached organisms from the boat and trailer
- Always dispose unwanted bait in the trash, never bring live bait into Montana without authorization
- Wash the exterior of your boat and trailer, hot-high pressure water is best
- Rinse and clean live wells, use hot soapy water or a weak bleach solution
- Allow boat to dry in between trips to different water bodies; ideally for 5 days
- Never move live fish, aquatic invertebrates or plants from one body of water to another without Fish, Wildlife and Parks authorization. It is unlawful to release any live aquarium or bait fish
- Report any potential sightings of zebra or quagga mussels (see description below) immediately to the Fish, Wildlife and Parks ANS Coordinator (406-444-2449), if possible, collect a sample, place it in a jar or zip-loc bag and note specific location and date
- Spread the word; tell your neighbors and friends about the importance of taking steps to prevent the spread of Aquatic Nuisance Species
- For further questions call the ANS Coordinator at 406-444-2449
How to identify Quagga or Zebra mussels
- Quagga and zebra mussels are similar in appearance
- Adults look like a small clam with a D-shaped shell
- Usually have alternating dark and light stripes, but these may not be present
- About the size of your fingernail, although can be up to 1-2 inches
- Small juveniles, which have just recently attached to a surface, look like black pepper and feel like sandpaper.

Quagga mussel on left, Zebra mussel on right, photo from USGS.
For more information, click on the following link https://cleandraindry.mt.gov/Aquatic-Invasive-Species
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