Invasive mussel forces boat to be quarantined at Tahoe

RENO -- A 32-foot cabin cruiser was quarantined at Lake Tahoe after a harbor master spotted invasive mussels encrusted on its stern as it was about to be hoisted into the water.

Wildlife and environmental experts describe the incident as a close call.

The harbor master at Tahoe Keys Marina in South Lake Tahoe spotted the mussels on the boat Aug. 22.

Experts later confirmed the mollusks were quagga mussels, which might have attached to the vessel while in Lake Mead in late July, said Ted Thayer, a natural resource specialist with the Tahoe Regional Planning Agency.

The boat on Thursday remained under quarantine as ordered by wardens with the California Department of Fish and Game.

"This is the first one we've actually found that actually had mussels on it," said Jenny Francis of the Tahoe Resource Conservation District, which is leading inspection efforts.

The incident, Thayer said, highlights the danger posed by mussel-infested boats and underscores the importance of detection programs.

"This tells us boats do come from Mead and there may be live mussels on board," Thayer said. "It is both scary and encouraging at the same time."

The owner said it was decontaminated when it left Lake Mead, Thayer said. He added that the mussels could have been dead by the time the boat came to Tahoe, but officials didn't want to take any chances.

Biologists plan to recheck the boat Sept. 3 to ensure it's clean before releasing it to the owner, Thayer said.

Quagga mussels, previously found only in the Midwest and Northeast, were first discovered in Lake Mead in early 2007 and have since spread to other parts of Nevada, Arizona and Southern California.

In January, zebra mussels, a close cousin of the quagga, turned up in a California reservoir 250 miles from Lake Tahoe.

Both types of mussels could cause problems if they were to become established in Lake Tahoe. The rapidly reproducing mollusks could quickly disrupt the lake's ecosystem, clog drinking water intakes, encrust boats, foul docks and litter beaches with sharp and stinking shells.

In June, the Tahoe Regional Planning Agency board approved rules requiring mandatory inspections of boats being launched into the lake.

But some launches still don't have inspectors available every day, leading officials early this month to ask marina operators to close boat ramps when no inspectors are available.

"We need to do everything we possibly can to make sure they don't get in the lake," said Mara Bresnick, chairwoman of the planning agency governing board.