The population of the small coffee-colored Asian clams has soared in the southeast portion of the lake, threatening to hog food sources and excrete nutrients that foster algae growth, according to an annual Lake Tahoe report by UC Davis researchers.
The population of the coffee-colored Asian clams has soared in the southeast portion of the lake, threatening to hog food sources and excrete nutrients that foster algae growth, according to an annual Lake Tahoe report by UC Davis researchers.
Scientists worry that calcium in the clams' shells could make the lake more hospitable to invasion by quagga or zebra mussels, which cluster onto boats and anything else that rests in the water. Although the mussels have not been sighted at Tahoe, authorities at other lakes have spent millions of dollars trying to control them.
"In a lake like Tahoe where a lot money and a lot of effort is being put into maintaining its pristine nature, the introduction or the threat of invasive species really pulls us away from that pristine condition," said John Reuter, associate director of UC Davis' Tahoe Environmental Research Center, which released Tuesday's "Tahoe: State of the Lake Report."
No one is certain how the Asian clam first arrived at Lake Tahoe, whose famed clear waters lie at the center of a multimillion-dollar tourism economy. Some authorities say that fishermen used the clams as bait and that surviving clams took root on the lake's bottom, where they released tiny offspring that were carried by water currents to other parts of the lake.
Visitors first noticed the white, partially oxidized shells on the shore seven years ago.