The Snake River Fund is calling on river users to wash their fishing and boating gear before entering the water, following the discovery of a destructive algae called didymo in Lake Creek last week.

Didymo is a type of algae that can form large mats and take over the bottoms of streams and lakes, diminishing habitat and food sources for fish and impeding recreation. Commonly called rock snot, didymo has wreaked havoc on streams in New Zealand, where the government has mounted an aggressive campaign to curtail its spread.

A study of Snake River tributaries by the U.S. Geological Survey this summer turned up large amounts of algae growing along Lake Creek near the Moose-Wilson Road bridge. Specimens were sent to a lab in Denver for testing, and the algae was confirmed to be didymo last week.

The USGS notified Grand Teton National Park of the discovery last week. Researchers had planned to search the Snake River for didymo, but the survey was called off because of high flows.

Snake River Fund has partnered with the U.S. Forest Service, Trout Unlimited, Jackson Hole One Fly Foundation and National Fish and Wildlife Foundation to prevent the spread of didymo and other “aquatic hitchhikers” to the Snake.

The groups installed wash stations at nearly all boat ramps between Wilson and Sheep Gulch earlier this month. At South Park, the lone exception, a wash station is planned.

The stations have tanks of fresh water and brushes for washing waders, booties, kayak bottoms and other fishing gear. Felt-soled boots are particularly susceptible to transplanting algae and other invasive species.

“For the most part the spread is human-originated,” said Lexey Wauters, executive director of Snake River Fund. “It’s really up to us to make sure that it doesn’t get spread.”

According to Wauters, didymo has the potential to “really decimate a watershed,” and scientists aren’t sure how to remove the algae once it has infected a stream or river. “Right now, we don’t have really good ways of treating watersheds,” Wauters said.  

River users should remember to remove any visible mud, plants, fish or animals before transporting equipment; eliminate water from equipment before transporting; clean and dry anything that comes into contact with water (boats, trailers, equipment, clothing, dogs, etc.); and never release plants, fish or animals into a body of water unless they came out of that body of water.

In addition, as the end of boating and fishing season nears, river users should treat their gear at home with a 2 percent bleach solution before storing the equipment for winter.

Other invasive species targeted by the Snake River Fund campaign include mud snails, whirling disease and Eurasian milfoil, a plant that forms large mats and has spread from lake to lake in Washington on boat trailers. Whirling disease and mud snails have been detected in several streams in the Snake River watershed.

Didymo has been found across western Montana and central Colorado. The algae also was discovered in Vermont this summer.

For more information on the national Stop Aquatic Hitchhikers campaign, visit www.protectyourwaters.net.