New Zealand Mudsnails Launch Invasion into Pennsylvania

New Zealand mudsnails are small, measuring less than one-quarter inch, with a long, narrow, coiled shell with deep grooves. Like other aquatic invasive species, they disrupt ecosystems by rapidly multiplying and competing with native species for space and food. 

The Pennsylvania Fish & Boat Commission confirm that New Zealand Mud Snails are in Spring Creek, Centre County, PA. Biologist with the PA Department of Environmental Protection took samples from the stretch between the state fish hatchery and Bellefonte, PA. Snail experts from South Carolina’s College of Charleston and the Smithsonian Institution’s National Museum confirmed the findings.

“Based on studies conducted in western U.S. streams, if the population grows quickly, they could become the dominant organisms in the benthic – or bottom dwelling – community, upon which many others species depend for food,” said Bob Morgan, the PFBC’s ecologist who studies aquatic invasive species. “Because this is the first known occurrence of the New Zealand mudsnail on the Atlantic slope of the eastern U.S, the effects of the snail on higher organisms, such as fish, are not certain at this time.”

 The mudsnail has spread to Europe, Asia, Australia and North America. They were discovered in the Snake River in Idaho and Wyoming in 1987; in Lake Ontario and the St. Lawrence River in 1991; and in Lake Erie about 4 miles north of Presque Isle Bay in 2007. Additional populations were found in a small stream near the Niagara River in New York in 2008 and in another Lake Ontario tributary in 2011.

“Spring Creek is one of the most heavily fished streams in the state, with anglers travelling to it from all over the world,” added Morgan. “Given the presence of the mudsnail in other areas of the country, it’s not surprising they have been found here. As with many aquatic invasive species, they are nearly impossible to eradicate once established. This is even more difficult with the mudsnail because it usually takes only one small snail to be able to produce offspring. But we must do our best to slow its spread to other waters.”

Anglers and boaters are urged to “Clean Your Gear!” before leaving a water and entering another one.

New Zealand mudsnails require some specialized disinfection measures. Gear should be visually inspected and any clinging matter should be removed and disposed of in the trash. To kill mudsnails, three methods are effective. Gear can be frozen for a minimum of six hours, or it can be soaked in hot water - 120°F to 140°F - for five minutes. This last method is not recommended for Gortex.

Also, a 2005 study by the California Department of Fish and Game showed that mudsnails can be killed by soaking gear for five minutes in a one-to-one solution of Formula 409® Cleaner Degreaser Disinfectant and water. After soaking gear for five minutes, thoroughly rinse it with plain water. Simply spraying gear with the disinfectant or the mixture does not work. Also, general cleaners have not been shown to be effective against the mudsnail.

If you suspect that you have found New Zealand mudsnail (or any other AIS) in another waterway, please report your information at: http://fishandboat.com/ais-reporting.htm. When reporting an AIS sighting it is very important to include as much information as possible including close-up photos of the organism, the exact location (GPS coordinates work best), a description of what you found, and your contact information.

For more information about New Zealand mudsnail, visit http://www.paseagrant.org/fact_sheet_group/invasive-species/ and scroll down to Fact Sheets – Invertebrates and the mudsnail photo/link.