Invasive New Zealand mudsnails discovered in Lake Tahoe

Divers monitoring Lake Tahoe have discovered invasive New Zealand mudsnails in areas off the South Shore, the Tahoe Regional Planning Agency  and Tahoe Resource Conservation District  announced Thursday. This is the first time the species has been detected in the Tahoe Basin.

The Lake Tahoe Aquatic Invasive Species Program includes comprehensive monitoring of Lake Tahoe for aquatic invaders. Contract divers with Marine Taxonomic Services, Ltd. surveying invasive weeds on the South Shore discovered tiny snails on the bottom of the lake nearly a half mile offshore from the mouth of the Upper Truckee River. Consultation with experts and a DNA lab analysis confirmed the species is New Zealand mudsnail, an aquatic invasive species that has been detected in nearby waterways including the Lower Truckee River downstream from Lake Tahoe near Reno, Nevada. No other AIS, such as the destructive quagga and zebra mussel, have been detected, according to the agencies.

Following rapid response protocols under the federally approved Lake Tahoe Aquatic Invasive Species Management Plan, TRPA convened an incident team comprised of staff from TRPA and Tahoe RCD and partner experts. The team is rapidly deploying scientists, beginning with lake-wide dive surveys to determine the extent of the infestation and sharing all available information with state and federal wildlife managers through the Lake Tahoe Aquatic Invasive Species Coordinating Committee. 

“Lake Tahoe is one of the most protected waterbodies in the United States and our aquatic invasive species monitoring program is credited as the reason for this concerning discovery,” TRPA Executive Director Julie Regan said. “It is critical that everyone remain vigilant and adhere to the mantra of Clean, Drain, and Dry. Every boater, paddler, and angler shares the responsibility to protect Lake Tahoe’s native species and the waters we enjoy.”

As climate change continues to affect Lake Tahoe’s native ecosystem, the threat of new invasive species taking hold in the region is increasing. Under the Lake Tahoe Environmental Improvement Program, the AIS Program is helping protect water quality and native species and is a key program to improve the climate resilience of the region, according to TRPA.