TROY, N.Y. The number of zebra mussels found in Lake George has declined dramatically since last year, when Rensselaer Polytechnic Institute researchers and volunteers began manually pulling the troublesome mollusks from the water.
The time-consuming, labor-intensive effort appears to be paying off. In the spring of last year, shortly after the first adult zebra mussels were discovered in the popular recreational lake, divers collected more than 19,000 of them. Last falls harvest netted 1,800. Since April of this year, however, divers have pulled only 352 mussels.
Of course, I cant guarantee that all of the zebra mussels are gone from Lake George. That would be premature. But I am optimistic, based on the numbers, that we got most of them at this site, said Sandra Nierzwicki-Bauer, professor of biology at Rensselaer and director of its Darrin Fresh Water Institute.
More good news is the size of the mussels pulled this year: All are too large to have been born in 2000 or 2001. Last years harvest seems to have culled the mussels before they reproduced, and they have not been found elsewhere in the lake.
Zebra mussel larvae were first found in Lake George in 1995, but researchers believed that lake chemistry probably low calcium and pH levels kept them from maturing. A culvert carrying storm runoff with high calcium levels may account for the proliferation of adult mussels at the site on the southeastern shore.
The mussels are a European invader already well established in Lake Champlain and the Hudson River. They can choke drinking-water pumps, foul outboard motors, and deter tourists. The mussels may have entered Lake George while attached to boats, boat trailers, anchors, bait buckets, or on equipment used in the construction of a nearby boardwalk.
The Darrin Fresh Water Institute is a member of the Zebra Mussel Task Force that includes the New York State Department of Environmental Conservation, the Lake George Park Commission, the La
Contact: Patrick Kurp
Rensselaer Polytechnic Institute