MILLTOWN — New Zealand mudsnails, an aquatic invasive species that can have a long-lasting impact on local waters, were discovered last week in Silverbow Creek near the outlet of Warm Springs Ponds. This is the first time mudsnails have been detected in the Upper Clark Fork watershed.
So far Montana Fish, Wildlife & Parks fisheries staff have only found two dead mudsnails in Silverbow Creek but will conduct follow-up surveys when the weather warms and it is more effective to find snails.
New Zealand mud snails are an aquatic invasive species found in a variety of waterbodies across Montana. The snails have the ability to expand in population size and distribution very rapidly, potentially changing the ecology of waterbodies where they are located. Once established, they are hard, if not impossible to eradicate.
In Montana, New Zealand mud snails were first detected in 1995 in the Madison River and have since spread to the Beaverhead, Jefferson, Bighorn, Upper Missouri, and Upper Yellowstone Rivers.
New Zealand mudsnails can survive for weeks out of the water and are easily transported on wading boots. The source of the recent mudsnail introduction was most likely due to angler wading gear that carried the snail from one body of water to another.
Prevention is the key to minimizing the spread of aquatic invasives. That’s why FWP urges anglers to clean, drain, and dry all equipment after each use, especially after visiting infested waters. If you see what looks like a New Zealand mudsnail, report it at fwp.mt.gov/conservation/aquatic-invasive-species/report-an-ais.