This article was originally published in Tahoe In Depth, Issue 31, Winter 2025.
In an unprecedented year of action and outreach, boaters, paddlers, and agency experts protected Lake Tahoe from invasive golden mussels. The collaboration and strengthened protections highlight why the Lake Tahoe Watercraft Inspection Program has become a national model for aquatic invasive species prevention.
Golden mussels require increased vigilance
When the Lake Tahoe Watercraft Inspection Program started in 2008, the closest invasive mussels to Lake Tahoe were in Lake Mead. Now, invasive golden mussels are only a three-hour drive from Tahoe’s unique ecosystem. Golden mussels have access to the entire California Water Project, a series of waterways and delivery systems spanning most of the state. Since the initial detection in the Sacramento-San Joaquin Delta in 2024, golden mussels have been detected as far south as Riverside.
If introduced, invasive golden mussels would irreversibly harm Lake Tahoe’s native ecosystem, water quality, and recreation opportunities, costing the region millions of dollars annually. The small bivalves reproduce rapidly and can clog pipes and damage infrastructure in a matter of weeks. Once established, they are nearly impossible to eradicate.
With the golden mussel at the doorstep of Lake Tahoe and to increase vigilance of the program, the Tahoe Regional Planning Agency (TRPA) and the Tahoe Resource Conservation District (Tahoe RCD) implemented mandatory decontamination following the already mandatory inspection. Inspectors decontaminated more than 4,700 watercraft in 2025, a 60 percent increase from 2024. Even with the safeguard of hot water decontamination, trained watercraft inspectors thoroughly inspect every vessel. The team intercepted 72 watercraft with aquatic invasive species, 14 of which had invasive mussels onboard.
A single golden mussel was found on a vessel from the Sacramento-San Joaquin Delta, sparking concern. The vessel was decontaminated and eventually cleared for launch, but the interception underscored the value of inspections.
A visual inspection of a boat seeking to launch in Lake Tahoe revealed that it was carrying a golden mussel. The boat’s previous voyage had been in the Sacramento-San Joaquin Delta.
Agencies and partner organizations also augmented outreach and stewardship programs to reduce the risk from non-motorized kayaks, paddleboards, and fishing equipment. Utilizing billboards, an interactive exhibit, and a chance-to-win campaign, partners in the basin broadcast one clear message: Clean, Drain, Dry all gear to protect the lake.
The free Tahoe Keepers training program saw one of its biggest years of growth with more than 800 new registrants. The expansion of four roving inspectors helped 17,000 recreators learn how to Clean, Drain, and Dry their gear.
Throughout California and Nevada, water managers responded to the threat of golden mussels with closures, quarantines, new programs, and crisis communications. With a seasoned, longstanding program, Tahoe managers shared their expertise to help other waterbodies protect themselves. The Tahoe program offered spare decontamination units to help protect waterbodies near the initial detection.
Golden mussels will remain a focus. In September 2025, the California Department of Fish and Wildlife officially added the golden mussel (Limnoperna fortunei) to a list of restricted species.
For the latest information on watercraft inspection, golden mussels, and how you can protect Lake Tahoe, visit TahoeBoatInspections.com and follow @TahoeBoating on social media.
McKenzie Koch is the AIS outreach and education specialist at TRPA.
Click here to read more articles from the 31st issue of TRPA’s environmental newspaper, featuring stories on the Emerald Bay shuttle pilot program, imitation beaver dams, Spanish-speaking advisor programs in the basin, and a new gateway mobility hub and watercraft inspection station at Spooner Summit in Nevada.