Scientists praise program to remove Tahoe weeds

SOUTH LAKE TAHOE, Calif. (AP) - Scientists have declared a pilot program to remove aquatic weeds from Lake Tahoe a success.

The use of more than 8,500 square feet of "bottom barriers" successfully eradicated most, if not all, of a swath of Eurasian watermilfoil from the floor of Emerald Bay on the lake's southwest shore, said Dan Shaw, an environmental scientist for the California Department of Parks and Recreation.

A similar technique involving plastic sheets is being used at Lake Tahoe to rob nonnative Asian clams of food and oxygen.

"We're very optimistic about the initial results of this pilot project because it demonstrates that it is possible to eradicate the majority of an infestation in a specific locale," Shaw told the Tahoe Daily Tribune.

"These findings will help us establish a control plan for aquatic invasive weed populations in Emerald Bay and other afflicted areas of Lake Tahoe," he said.

Eurasian watermilfoil, a fast-growing aquatic plant that crowds out native species and snarls motorboat propellers, has been held at bay with the barriers at a lake in New York's Adirondacks.

In June, a partnership including Shaw's agency, the Tahoe Resource Conservation District and the Tahoe Regional Planning Agency placed the bottom barriers on the nonnative plant at Emerald Bay near Swim Beach. Divers also removed the weeds by hand outside the barriers.

On Sept. 14, divers found no signs of invasive weeds where the barriers had been placed, said Kim Boyd, invasive species manager at the conservation district.

The success of the operation has prompted plans to treat other sites at Lake Tahoe where Eurasian watermilfoil is present, Boyd said.

"Our goal is to get the population of invasive plants in Tahoe back to a manageable size," she told the Tribune.

A similar technique will continue to be used to control the growth of curly-leaf pondweed, another invasive plant at Lake Tahoe.