Divers battle upstate clam infestation

LAKE GEORGE -- Tourists are long gone from the lake, but the fight against an invasive clam will keep scuba divers in the chilly waters through the middle of December.

Efforts began this spring to smother the invasive, dime-sized Asian clam, Corbicula fluminea, by placing large mats on the five acres of lake bottom off the village, not far from Million Dollar Beach, and the fight has expanded this fall to include efforts to suction up clams further up the lake in Middleworth Bay in the town of Bolton, said Peter Bauer, executive director of the Fund for Lake George.

Armed with hoses from floating pontoon boats, divers have been suctioning up six inches of lake bottom to get the clams, he said. The hoses feed a large debris bag, which separates the clams before filtering the water back to the lake.

Suctioning is being tried in areas where mats cannot be used, such as under wharves, on rocky bottoms and in shallow water, Bauer said.

In the fall, underwater mats were placed on clam infestations found on three acres near the village, where mats put in during the spring had been taken out during the summer tourist season, and on 2.5 acres near Norowal Marina in Bolton, he said.

The mats will have to come out of the water in several weeks. After that, Bauer said, six divers will examine 12 acres -- 11 acres that had been matted, and the one acre that was suctioned -- to determine how effective the first year's effort against the clams was.

That will help determine what needs to be done next year to try to make Lake George the first infested body of water to be purged of the clams.

About $650,000 has been spent this year on the effort, and Bauer said that much again likely will be needed to continue next year. Boon Bay, also in Bolton, has a clam infestation that was not treated this year.

"This is easily going to top $1 million," he said. "We are out looking for money now, from the state and from private sources." The clam control effort had an initial budget of about $475,000, provided in part by the park commission, the New York State Department, the Department of Environmental Conservation, the Lake Champlain Basin Program, Warren County and the town and villages around the lake.

First found in Lake George in the fall of 2010, the Asian clams excrete nutrients that can fuel algae blooms. The sharp-edged clams can wash up dead along shorelines, making it risky to walk in bare feet.

The self-fertilizating clams can release up to 400 young a day during reproduction in May and August. Rapidly growing colonies can carpet a lake bottom, reaching densities of thousands per square yard.