Mussels triggered prevention program that has intercepted thousands of contaminated watercraft

By Brita Romans and Tom Lotshaw/Tahoe Regional Planning Agency

An ounce of prevention is worth a pound of cure, as the saying goes. And watercraft inspectors are Lake Tahoe’s frontline defense to prevent new introductions of aquatic invasive species that would cost tens of millions of dollars to manage or eradicate — if they could be managed or eradicated at all.

This summer marks the 10th anniversary of Lake Tahoe’s watercraft inspection program. In that time, the program has grown into a national model for invasive species prevention and the boat inspectors have successfully prevented any new introductions of aquatic invasive species.

“This major milestone highlights the importance and success of this critical program,” said Chris Kilian, who became a watercraft inspector 10 years ago and now manages the program for the Tahoe Resource Conservation District.

Kilian and his team of trained, certified watercraft inspectors work to check every motorized boat and jet ski for aquatic invasive species before launching in Lake Tahoe’s famously clear, blue water —protecting the lake’s environment, economy, and recreational opportunities.

An inspector decontaminates a boat prior to launch. Photo: Novus Select

The inspection program was launched when highly invasive quagga and zebra mussels were being spread west from the eastern United States and Great Lakes, hitching rides on boats, trailers, and other fishing and water recreation equipment. Quagga mussels reached Lake Mead in southern Nevada in 2007, where they now number in the trillions.

Forty partner agencies, non-profit groups, and private organizations working together as the Lake Tahoe Aquatic Invasive Species Program launched a voluntary watercraft inspection program in 2008 and inspections became mandatory in 2009.

The invasive mussels have been impossible to control or eradicate once introduced and have wreaked havoc on every waterbody they have reached in America. They are easily spread, attaching to nearly any surface, and once introduced to a new lake or river, they can reproduce at an alarming rate. One adult quagga can produce up to a million offspring each year.

“The mussel larvae, called veligers, are about 20 microns in size. You can’t see them with the naked eye, so the “Clean, Drain, Dry” system greatly reduces the risk of bringing any new invasive species to Tahoe,” Kilian said.

The program quickly caught boats carrying the invasive mussels. Inspectors regularly intercept boats carrying invasive species, but more boaters are showing up to Tahoe with their watercraft clean, drained, and dry.

Tahoe’s watercraft inspection program shows how local, state, and federal agencies and private organizations can partner to protect lakes and rivers from new invasive species introductions.

In the beginning of the program, watercraft inspectors traveled around the basin to boat ramps and marinas to inspect and decontaminate boats before they launched. The inspectors now operate out of four stations around the Tahoe area during the peak boating season from May through September. They examine every motorized boat, jet ski, and trailer, looking for signs of mud, debris, or water carrying invasive species.

Boats found to be clean, drained, and dry are affixed with a wire seal that allows them to launch at marinas and boat ramps.

Boats that do not arrive at the inspection station clean, drained, and dry must be decontaminated to kill any possible invasive species before they are allowed to launch.

Boaters who enjoy wakeboarding are encouraged to fill and empty their ballast tanks in the same place to help prevent the spread of species that have already taken hold in the lake, such as Eurasian watermilfoil and Asian clams.

Funding for the watercraft inspection program comes from boater inspection and decontamination fees, which cover about half of the program’s costs. The other half is funded by the states of California and Nevada, and the federal government.

“We couldn’t have started this nationally recognized program without the support of our congressional delegation and the federal government,” said Julie Regan, TRPA’s chief of external affairs. “Now the states of California and Nevada sustain the public funding that makes the program possible. It’s the public-private partnership that’s so strong.”

Brita Romans is a recent graduate of the University of Nevada, Reno and an intern at TRPA. Tom Lotshaw is the public information officer at TRPA.