Boat Inspectors Keep Golden Mussels Out of Tahoe

LAKE TAHOE, Nev./Calif. – Lake Tahoe boat inspectors intercepted 10 watercraft carrying invasive golden mussels this season as part of 5,200 inspections, reported Tahoe Regional Planning Agency (TRPA) officials in an end-of-boating-season briefing today.

TRPA and the Tahoe Resource Conservation District (Tahoe RCD) lead the Lake Tahoe Watercraft Inspection Program which protects Lake Tahoe from aquatic invasive species (AIS) that can irreversibly harm water quality, clarity, and quality of life in the Tahoe Basin.

For the second year, the program required mandatory decontamination of all visiting motorized watercraft without an intact inspection seal, a critical response to the invasive golden mussel infestation in nearby California waterways. Inspectors intercepted one boat in 2025 with invasive golden mussels.

“Increasing golden mussel interceptions was not unexpected given the species’ rapid expansion in waters from San Diego to Sacramento, but the discoveries underscore the importance of continued vigilance,” Chris Kilian, aquatic invasive species program manager at Tahoe RCD, said. “Thankfully, our team of trained inspectors is dedicated and meticulous.”

This year, nearly 70 percent of all visiting boats arrived Clean, Drained, and Dry, up from 60 percent in previous years, reflecting a new fee incentive for vessels that meet inspection protocols.

“Arriving Clean, Drain, Dry is the most impactful action boaters can take to prevent the spread of invasive species,” Thomas Boos, aquatic invasive species prevention program manager at TRPA, said. “We are excited and grateful to see this continued shift in boater behavior. It will not only protect Lake Tahoe, Fallen Leaf Lake, and Echo Lake from invasive golden mussels, but also waterways across the U.S.”

The boat inspection program discovered 84 vessels traveling to Tahoe with various aquatic invasive species on board. Of the 84 vessels, inspectors recorded 23 vessels with invasive quagga, zebra, or golden mussels. Invasive mussels can irreversibly harm Lake Tahoe’s recreation, water quality, and ecosystems. They are notorious for encrusting pipes, piers, rocks, and moored boats, and for decimating native and sportfish populations.

Each mussel interception is different, according to inspectors. Some boats carried a single mollusk, while others arrived with hundreds of mussels encrusting the stern. In one case, golden mussels were found hitchhiking on plant matter after a boat took a quick dip in the Sacramento-San Joaquin River Delta, reminding everyone that the threat of AIS lurks in mud, water, and plants as well.

Hundreds of invasive golden mussels cling to the back of a boat traveling from the California Delta. Photo by: Tahoe Resource Conservation District

By the Numbers

2026 Boating Season by the Numbers:

5,200 inspections
Nearly 70 percent arrived Clean, Drained, and Dry
84 vessels with AIS intercepted

20 with Corbicula clams
17 with milfoil
13 with quagga or zebra mussels
11 with marine life
10 with golden mussels
9 with non-native mollusks
3 with false mussels
1 with New Zealand mudsnails

700 new Tahoe Keepers certified

All-Time Numbers:

128,000 inspections
8,900 Tahoe Keepers certified
910 AIS intercepted

Clean, Drain, Dry applies to all watercraft

Any equipment that touches the water poses a risk, as tiny invaders can stow away in standing water or equipment crevices. Partners across Tahoe continued to elevate Clean, Drain, Dry outreach to kayakers, anglers, and beachgoers through trainings, digital marketing, and outreach at popular beaches. The free online Tahoe Keepers training program certified 700 new non-motorized recreators during the 2026 paddle season. The community of beachgoers committed to protecting the waters of Lake Tahoe, Fallen Leaf Lake, and Echo Lakes has grown to 8,900 registrants.

Four new waterless cleaning machines, funded by Keep Tahoe Blue donors, were placed at Fallen Leaf Lake and Baldwin Beach in August 2026. This doubled the fleet of “CD3 Machines” designed to help prevent the spread of invasives already present in Lake Tahoe, like watermilfoil and New Zealand mudsnails, to other waterbodies in the Tahoe Basin.

Additionally, more than 300 paddlers took advantage of free hot water decontamination services at Tahoe boat inspection stations, a three-fold increase in voluntary non-motorized decontaminations, representing the highest level of protection for Tahoe’s pristine waters.

Hot water decontamination kills aquatic invasive species that could hitchhike on watercraft and equipment. Credit: Clean Up the Lake

Appointments mandatory for winter decontamination

Decontamination continues to be essential to protect Lake Tahoe, even when temperatures drop. Aquatic invasive species have broad temperature tolerances and can survive even the iciest of Tahoe winters. From October through April, inspection and decontamination will be available by appointment at the Meyers inspection station. Visit tahoeboatinspections.com for more information.