RENO — A nonnative snail discovered in the Truckee River around Reno earlier this year exists in greater numbers than expected, Nevada Department of Wildlife officials said.
Surveys completed Wednesday show New Zealand mudsnails are established along an 18-mile stretch of the river from Reno to Mustang east of the city, said Chris Crookshanks, a department fisheries biologist.
Officials had said they could confirm the snail’s existence only in a 1-mile section of the river near Reno after detecting them for the first time in the waterway earlier this year.
Mudsnails range from the size of a grain of sand to an eighth of an inch and can thrive in huge numbers, with up to 900,000 per square yard found in some places.
Crookshanks said the mollusks compete with bugs and native invertebrates for food, and could cause major harm to the Truckee’s ecosystem and prized trout fishery.
Officials also have said the presence of the mudsnails in the river increases the chances the invasive species could migrate to the Lake Tahoe Basin. The river flows more than 100 miles from Lake Tahoe to Pyramid Lake, 30 miles northeast of Reno.
There is no effective way to eradicate the snails, Crookshanks said, and it’s unknown how large the infestation might become.
“Time will tell what kind of habitat the river offers for them,” he told the Reno Gazette-Journal.
He said densities found in some areas were unexpected and suggest the snails have been in the river for some time. Officials originally speculated the infestation was relatively recent.
“In order for them to spread out that much, they’ve been here awhile,” Crookshanks said. “It really surprises me they went undetected for so long.”
Department of Wildlife officials will meet Aug. 7 with representatives of other agencies to determine the next course of action.
Among other steps, they’ll consider plans to establish decontamination stations and to launch a public education campaign notifying the public what it can do to prevent the spread of the snails.