Mats effective in killing invasive clams on East Coast
By Brian Nearing, Times Union
LAKE GEORGE, N.Y. — Scuba divers will plunge into the chilly waters of Lake George this month to start the second year of a campaign aimed at eradicating the invasive Asian clam before it spreads through the lake.
Last year, after divers put hundreds of plastic mats over a clam-infested, five-acre patch of lake bottom north of Million Dollar Beach, it proved to be 99 percent effective in suffocating clams by denying them oxygen.
But researchers also found a few clams from under the mats that appeared neither alive nor dead, raising questions whether the creatures may enter a kind of suspended animation in cooler water to avoid suffocation, said Sandra Nierzwicki-Bauer, director of the Rensselaer Polytechnic Institute’s Darrin Fresh Water Institute.
“This was not something that we had seen before,” she said. For now, such zombie-like clams are being labeled as “inactive” by researchers. “We are hoping that in surveying by divers this spring, we will find out what happened, if those clams eventually died or were able to recover.”
First found in Lake George in the fall of 2010 and likely brought into the lake by unwitting boaters, the dime-size clams excrete nutrients that can fuel algae blooms. The sharp-edged clams can wash up dead by the thousands along shorelines, making it risky to walk in bare feet.
Capable of self-fertilization, 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. Infestations have spread out of control in Lake Tahoe.