Lake Tahoe Threatened by Warming?

March 25, 2008 -- A new study predicts water circulation in Lake Tahoe is being dramatically altered by global warming, threatening the lake's delicate ecosystem and famed clear waters.

The University of California, Davis study said one likely consequence is warmer lake temperatures that will mean fewer cold-water native fish and more invasive species -- like carp, large-mouth bass and bluegill.

"What we expect is that deep mixing of Lake Tahoe's water layers will become less frequent, even nonexistent, depleting the bottom waters of oxygen," said Geoffrey Schladow, director of the Tahoe Environmental Research Center at UC-Davis.

Schladow, Associate Director John Reuter and postdoctoral researcher Goloka Sahoo presented the findings last week in Incline Village at a conference focusing on global warming and deep-water lakes.

The changes, the study concluded, could turn Tahoe's famed cobalt-blue waters to a murky green in about a decade.

"A permanently stratified Lake Tahoe becomes just like any other lake or pond," Schladow said. "It is no longer this unique, effervescent jewel, the finest example of nature's grandeur."

Schladow said researchers are trying to determine if lowered global greenhouse-gas emissions would significantly slow the lake's decline or possibly prevent it.

On average, water in Lake Tahoe -- at 1,644 feet deep -- mixes every four years, the researchers said.