By Peter Brumis

Watercraft inspection data and scientific reports continue to indicate that Lake Tahoe’s waters remain clear of invasive Quagga and Zebra mussels, which are considered major threats to Lake Tahoe and surrounding water bodies. Tahoe Resource Conservation District (Tahoe RCD) watercraft inspectors performed 8,000 inspections this boating season, and there were an additional 19,000 launches comprised of watercraft with intact Tahoe-issued inspection seals.

“We’re very happy with the watercraft inspection program thus far,” said Patrick Stone, TRPA’s senior wildlife and fisheries biologist and lead for early detection monitoring of invasive mussels. “Investigations conducted around Lake Tahoe, Fallen Leaf Lake, and Echo Lake confirmed that Quagga and Zebra mussels have not established in our lakes. These results are a credit to the inspection program.”

Fallen Leaf Lake has a decontamination facility.

Concern among local agencies remains high, as more Western water bodies have shown evidence of invasive mussels and other aquatic invaders. Water bodies in California and Nevada known to be infected with invasive mussels include San Justo Reservoir, Lake Mead, Lake Havasu, and the entire Colorado River system. As watercraft continue to arrive from high-risk waters, the importance of Lake Tahoe’s watercraft inspection program remains critical.

Federal appropriations through the U.S. Fish and Wildlife Service in 2010 enabled the program to implement off-highway inspection stations. This created an opportunity to streamline inspection procedures and increase decontamination capacity.

2010 saw a dramatic increase in watercraft decontaminations, which doubled from approximately 600 in 2009 to 1,208 this year. Improved decontamination capacity at off-highway inspection locations allowed inspectors to be more thorough in treating high-risk watercraft. Additional improvements to inspection protocol allowed inspectors to increase prevention efforts by intercepting watercraft arriving from waters known to be infested with aquatic invasive mussels.

Eleven watercraft showing the presence of aquatic invasive species of concern were intercepted and decontaminated.

“It only takes one contaminated boat to introduce aquatic invasive species into Lake Tahoe,” said Tahoe RCD Biological Resources Program Manager Kim Boyd. “We need to remain vigilant and not let our guard down. We hope that by demonstrating the success of the watercraft inspection program for Lake Tahoe, the Tahoe RCD and its partners can create a model for prevention programs by sharing our resources and providing support. The TRPA, our key partner in invasive species prevention, continues to be instrumental in the success and evolution of this program.”

While the addition of convenient off-highway locations enabled boaters to receive their watercraft inspections and decontaminations when entering the Lake Tahoe Basin, marinas and boat launches continued to be the busiest locations for inspections in 2010. Cave Rock saw the most inspections, followed by the Tahoe Keys Marina, Lake Forest Boat Launch, Meyers Inspection Station, Alpine Meadows Inspection Station and Sand Harbor. Off-highway inspection stations accounted for approximately 31 percent of all inspections performed during the 2010 boating season.

This year’s prevention efforts also included a more rigorous non-motorized watercraft inspection process at ramp facilities, US Forest Service kiosks and Fallen Leaf Lake. Tahoe RCD inspectors surveyed over 1,900 paddlers to assess the risk of transporting aquatic invasive species from previously visited water bodies. Paddlers were also educated about self-inspecting and decontaminating canoes, kayaks and paddleboards.

Current information on the boat inspection program, including hours of operation for boat launches and snow closures, is available online or by calling 888.824.6267.

Peter Brumis is public outreach specialist for the Tahoe Resource Conservation District.