Making a side trip during his July Fourth holiday weekend, Gov. Gray Davis became the latest dignitary to get a first-hand lesson on the health of Lake Tahoe from the scientists of UC Davis' Tahoe Research Group. As the S.S. John Le Conte bobbed in choppy Tahoe waters, research group director Charles Goldman told the governor about the precipitous decline in lake clarity--more than a foot per year--and explained UC Davis research that shows a dangerous depletion of oxygen in the deep waters. UC Davis Tahoe researcher Bob Richards scooped up bright red plankton from the lake depths and explained the threat to the food chain to the crowd on the Le Conte deck, which included First Lady Sharon Davis, state Environmental Protection Agency Secretary Winston Hickox, Chancellor Larry Vanderhoef and his wife, Rosalie, Tahoe Research Center campaign chairman Charlie Soderquist and his wife, Janie, Vice Chancellor for University Relations Celeste Rose and numerous reporters and camera crews. The July 2 visit was Gov. Davis' first to Lake Tahoe since 1995, and he expressed serious concern about the lake's future. "When you see firsthand the clarity issue, you realize we are squandering a precious resource," the governor said at a press briefing on the boat dock. "The lake greatly impacts the economy of Northern California, it's not just the beauty." Davis took the occasion to announce that he had ordered Caltrans, which clears Tahoe roadways in the winter months, to change snow-removal practices, such as salting, that contribute to the lake's deterioration. UC Davis' research has found that road dust, car and boat emissions, golf course fertilizers and sediment runoff from throughout the Tahoe region watershed all contribute to a "nutrient load" that fosters algae growth and reduces the lake's clarity. Bacteria from the algae then break down and consume oxygen in the lower depths of the lake, allowing even more algae-promoting nutrients to migrate toward the lake surface. "If we ever lose the oxygen in the deep waters of Lake Tahoe, the battle will be lost," Goldman told the governor. He reiterated his prediction that California and Nevada have about a decade to change policies and practices and turn around the decline in lake health before the impact is irreversible. Goldman will continue to make his case for Tahoe at numerous appearances and boat tours scheduled for this summer as part of the UC Davis Campaign for Lake Tahoe, which aims to raise $12 million to build a state-of-the-art laboratory, as well as classroom and meeting facilities, in Tahoe City. The lab would replace current makeshift lab facilities now housed in a historic, though crumbling, former fish hatchery. In May, California Attorney General Bill Lockyer and Nevada Attorney General Frankie Sue Del Pappa toured the lake aboard the Le Conte. Later this month, Cal EPA Secretary Hickox, who has expressed his support for UC Davis' Tahoe efforts, will make another voyage with the research group.