Kristen Rohne of the Lake George Association searches for Asian clams. The invasive species has been found at a private boat launch area in Glenburnie.
Spring post-treatment survey results suggested that the seven acres of mats placed on the lake floor last winter successfully killed off populations of Asian clams in Lake George. However, a two-week lakewide survey currently in its second week reveals that the invasive clams are showing up in new locations as well as spreading beyond the treated areas.
New clam populations have been identified by volunteers and staff from the various organizations that make up the Lake George Asian Clam Task Force. New locations with clams have been found at Million Dollar Beach, Sandy Bay, Cotton Point and Basin Bay in southern Lake George, as well as the private boat launch area in Glenburnie in the Northern Basin.
“We have a sound and proven method to kill off the clams that we treat, but it’s not enough to contain them,” said Walt Lender of Ticonderoga, executive director of the Lake George Association.
“While it is unfortunate that we have moved beyond an eradication and containment strategy to a long-term management and control operation, we are still able to build upon our past successes to learn more about the clams so that we can better manage them. The detection of the juvenile stage of the clams is the challenge; control has been successful where clams larger than 2mm are found. We need to continue surveys to document the rate of spread and study the species in more detail to understand what we can do to best manage the population” said Meg Modley, the Lake Champlain Basin Program’s aquatic invasive species management coordinator.
“This latest news demands targeted research aimed at understanding the lifecycle of the Asian clam which will open new doors to more effective treatments that can stop the spread and limit impacts to the lake to the fullest extent possible,” said Dr. Sandra Nierzwicki-Bauer, director of the Darrin Fresh Water Institute.
“This is not the time to throw in the towel, but, rather, to redouble our efforts to develop better methods for treating the problem without delay. This will take concerted action and commitments from regional, state and federal interests to achieve success. The value of Lake George as a natural treasure of international importance warrants such initiative,” said Eric Siy, executive director of the FUND for Lake George.
Plans are still being developed for the new sites as well as expansions of existing sites.
“Based on survey findings, our control strategy for the more established sites was thwarted by the aggressive reproductive abilities of these invasive clams,” said Chris Navitsky, Lake George Waterkeeper. “This development only amplifies the need for mandatory measures to inspect and decontaminate all trailered boats before entering the Lake. Protection from invasives ultimately requires prevention while we study new and better ways to tackle those species that are already here.”
Plans are still in the works for the next round of treatment.
“We are prioritizing locations based on a series of factors including spread potential, research value, recreational uses, density of clam populations, and ecological sensitivity, but there are many things to consider and not enough resources to do everything we want to do,” Lender said. “At the top of the list for right now is trying to find out whether the adult clams in the lake have just released another generation of offspring. This is going to be a difficult and labor-intensive process because samples of water and sediment must be carefully examined under a microscope in a lab, but finding this out now will inform our upcoming fall efforts.”
Dave Wick, executive director of the Lake George Park Commission, reaffirmed, “This Task Force has successfully adapted and honed management techniques for adult populations of Asian clams in Lake George, and will continue to shape monitoring, research, and management efforts as necessary to identify and address the invisible spectrum of juvenile populations, and mitigate the impact of this species upon the resources of the park.”