August 19, 2009

Tiny Asian clams invade Lake Tahoe

A tiny import, the Asian clam, is a growing problem in Lake Tahoe on the California-Nevada border.

The dime-sized bivalves were first noticed in the lake bottom in 2002, the San Jose (Calif.) Mercury News reported.

Now, they have spread to an area on the south shore.

Lake Tahoe is a place that people have tried hard to protect, said John Reuter, an aquatic ecologist with the University of California at Davis. "These invasive species get us further and further away from the pristine

condition of the lake that people would like to see."

While the clams are small, they are fecund, producing up to 100,000 new clams during their four-year life spans. They burrow in the mud and can live from the shoreline to 140 feet underwater.

Scientists worry that the clams will consume so much plankton native fish will starve and that their waste will feed algae blooms.

The clams have lived for decades in the Sacramento River and a saltwater cousin lives in San Francisco Bay. They may have been brought to Lake Tahoe by people using them as bait.