The Poly Archives: Invasive Asian clams in Lake George

This article was originally published in The Polytechnic.

An invasive clam species was discovered to be inhabiting nearby Lake George on August 19. Efforts are underway to gauge the extent of the infestation and eventually eradicate the Asian clam (Corbicula fluminea) from Lake George in order to prevent threatening the native clam species (Elliptio complanata) and spoiling the water supply.

RPI graduate student Jeremy Farrell, of the Darrin Fresh Water Institute, was the first to discover the infestation. Farrell obtained his undergraduate degree in ecology from Union College and is currently a Ph.D. student in Rensselaer’s Department of Biology. He started working at Darrin Fresh Water Institute as an intern in 2003.

The U.S. Geological Survey states that if the Asian clam makes its way to electrical or nuclear power plants, some potential hazards include clogging of pipes, drains, and other equipment, as well as reducing energy production efficiency. The process of managing the population of Asian clams has proven to be costly.

According to Executive Director of FUND for Lake George Peter Bauer, “In Lake Tahoe, they’re spending 1.4 million dollars this year to try and manage the clam. The rapid [population growth] generates extensive excrement that facilitates more algae. This cycle leads to decreased water quality.”

So far, investigations are underway to determine how much the Asian clams have spread. Methods such as SCUBA diver surveys have been used to learn the extent of the invasion. Previously, researchers were unsure as to whether the infestation levels were too high to completely remove the Asian clam from Lake George; however, recent investigations indicate that it is possible to completely eliminate the invasive clam from the lake.

According to Bauer, “Staff scientists at the Darrin Fresh Water Institute have conducted fieldwork on the lake bottom to ascertain the extent of the infested area … Based on what we’ve found, we’re planning to eradicate, not simply to manage.”

The method that will be used to remove the clams has still not been decided, however, possible approaches include benthic barrier, suction harvesting, or a combination of both. The decision will be announced in a couple of weeks.

The Darrin Fresh Water Institute originally estimated that the Asian clam infestation spanned approximately 2.5 acres, however, additional fieldwork has shown that the area is larger. Director of the Darrin Fresh Water Institute and professor of Biology Sandra Nierzwicki-Bauer explained, “We are collecting core sediment samples—which would have clams in them if present—from 60 locations to further define the acres that are infested. We will have this work completed by the end of this week.”

Nierzwicki-Bauer also stated that an updated estimation of the extent of the infestation will be ready by the end of the week after the core sediment samples have been analyzed.

In the past, Lake George has seen infestations from other freshwater species such as Eurasian watermilfoil, zebra mussels, Curlyleaf Pondweed, and Brittle Naiad. These species are still present in Lake George, however, are closely managed or are in the process of being eradicated from the area.

“All invasives require an active annual in-lake survey by divers trained to identify and remove these plants,” Bauer said. Efforts are also being made to contact other lake associations to alert them to the possibility of boaters spreading the infestation.

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