A Brand-New Invasive Species Has Been Discovered in Lake Tahoe

Lake Tahoe faces a new threat as invasive New Zealand mudsnails have been discovered in its iconic waters. This alarming finding marks the first time this invasive species has been detected in the Lake Tahoe Basin.

The Lake Tahoe Aquatic Invasive Species Program, responsible for monitoring Lake Tahoe for aquatic invaders, recently made the discovery during comprehensive surveys. Contract divers conducting a survey of invasive weeds on the South Shore found tiny snails on the lakebed nearly half a mile offshore from the mouth of the Upper Truckee River. Subsequent DNA lab analysis confirmed that these snails are indeed the New Zealand mudsnail, an aquatic invasive species.

Although the New Zealand mudsnail has been detected in nearby waterways, including the Lower Truckee River downstream from Lake Tahoe, no other aquatic invasive species species, such as the destructive quagga and zebra mussels, have been found in the lake.

“The recent discovery of New Zealand mudsnails in our Lake is disheartening, but not unexpected,” said League to Save Lake Tahoe CEO Dr. Darcie Goodman Collins. “Tahoe’s program to manage aquatic invasive species leads the nation, but it does have gaps and room for improvement – in the need for more frequent lakewide surveys and stronger inspection requirements for recreational equipment. This discovery shines a light on them.”

Officials have initiated rapid response protocols outlined in the federally approved Lake Tahoe Aquatic Invasive Species Management Plan. An incident team has been formed and the team is rapidly deploying scientists to conduct lake-wide dive surveys to assess the extent of the infestation and is 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.”

Invasive species can be introduced through various means, including boats, fishing gear, paddle craft, and beach toys. The most effective prevention method is to thoroughly clean, drain, and dry boats and gear before entering a new waterbody.

“Lake Tahoe’s robust watercraft inspection program, and commitment from the public, shows that preventing the spread of aquatic invasive species is possible,” said Lisa Heki, Lahontan National Fish Hatchery Complex Project Leader, U.S. Fish and Wildlife Service. “Now more than ever, we have to support and strengthen our work with anglers, boaters, paddlers, and everyone who interacts with the waters of Lake Tahoe and its 63 tributaries.”

Periodic monitoring for invasive species is an integral part of the Lake Tahoe AIS Management Plan, ensuring early detection and rapid response to potential threats. This approach has also been instrumental in controlling the spread of aquatic invasive weeds introduced before the inspection program, such as the ongoing weed removal project in Emerald Bay.

“As Lake Tahoe’s popularity grows, and the effects of climate change make the ecosystem more vulnerable, everyone who enjoys Tahoe must do their part to protect it,” said Collins. “That starts with cleaning, draining and drying every piece of equipment that touches the Lake, from your sandals and life vests, to your kayak and ski boat, including your waders and all fishing gear.”