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Zebra mussels found in state (Released: 9/24/98)

Office of University Communications

SALISBURY, Conn. -- Connecticut is the latest state to be invaded by zebra mussels, according to Nancy Balcom, an expert on nonindigenous species invasions for the Sea Grant College Program at the University of Connecticut.

The discovery of the mussels in East Twin Lake, located in the Northwest hills in Salisbury, is the first confirmed sighting in the state and only the second discovery of the mussels in New England. (The mussels are also found in Vermont.) The mussels have been growing in New York lakes and the Hudson River, as well as in Lake Champlain for a number of years, but had not been found in Connecticut until now.

Discovered during an aquatic weed harvest operation, the mussels were given to Donald Mayland, a science teacher from Hotchkiss School in Lakeville who made a preliminary identification, later confirmed by Dr. David Strayer of the Institute of Ecosystem Studies, in Millbrook, N.Y. The mussels were up to 15 millimeters in length, indicating that they may have been introduced to the lake in late 1997 or early 1998. Multiple specimens were found attached to aquatic weeds, but they were sparse.

Zebra mussels, native to the Black and Caspian Seas, have caused millions of dollars of damage in the U.S. and Canada, particularly in the Great Lake region and Mississippi River basin. The mussels are fouling organisms, secreting tiny threads to attach themselves to rocks, aquatic weeds and industrial and residential water intake pipes. The mussels rapidly form large reefs, reducing or blocking water flow through the pipes, often causing major problems for power companies. The mussels can also alter local aquatic ecosystems by using the food supply and habitat of native organisms.

The thumbnail-sized freshwater mollusks have been rapidly spreading throughout river and lake systems in the eastern half of North America since the mid 1980s.

"Unfortunately, it was just a matter of time until the mussels invaded Connecticut," said Balcom. "Western Connecticut has always been the most likely place for the mussels to show up, being close to the New York border and subject to a lot of interstate boat traffic from areas with zebra mussels. The Twin Lakes also have the high calcium level in the water that the mussels need for shell formation."

David Leff, assistant commissioner of the state Department of Environmental Protection, said the state has worked with UConn Sea Grant to identify potential waters susceptible to infestation and to educate the public on the problem since 1994.

"The discovery of zebra mussels in a Connecticut lake is not unexpected," Leff says. "The state is concerned over the potential impacts to the environment and water dependent industries."

Balcom, based at the University of Connecticut's Avery Point campus, has been conducting educational outreach since 1992 to warn of the potential zebra mussel invasion and instruct boaters and lake managers on steps to take to prevent their spread. The Sea Grant programs have a Congressional mandate to support research and education regarding zebra mussels. Recently, Balcom was among several Sea Grant experts summoned to Ireland to provide advice after the Shannon River was invaded.

An informal task force on zebra mussels was established by Balcom in 1992 comprised of representatives from industry, academia, anglers, lake managers and the DEP. The group met regularly for several years to develop strategies for monitoring and controlling the mussels, and will soon reconvene to discuss limiting the spread of the mussels in the state. The DEP will be a key player on the task force, and will step up its education programs, says Leff.

The task force had three main goals: identifying waters susceptible to infestation, developing recommendations to control the spread of the mussels and developing methods of addressing the problem. UConn, in cooperation with DEP and the task force identified lakes with high calcium concentrations, the ones most likely to foster zebra mussel growth.

UConn then developed a survey in conjunction with DEP and the task force to gather information on boat use patterns in three Connecticut lakes, Candlewood Lake, Lake Zoar, and Lake Lillinonah. The information collected was used to develop methods to help prevent spread of zebra mussels and develop means --- including signs posted at boat yards, public service announcements, mailings to boaters and information in DEP's Anglers Guides to educate the public.

"We have been monitoring for zebra mussels in the Housatonic and Connecticut Rivers for more than five years," said Milan Keser, supervisor of the Northeast Utilities Environmental Lab, and a co-chair of the task force. "Our last check in the Housatonic River and Candlewood Lake earlier this month turned up no sign of the mussels. However, now that they're here, we'll be re- convening the task force to discuss plans with renewed vigor."

"We've been expecting them for five years," said James T. Carlton, one of the world's top experts on exotic species invasions. "I believe that it's only because of the efforts of Sea Grant and the state that they didn't invade much sooner." Carlton, the director of Maritime Studies at Mystic Seaport/Williams College, has received $750,000 in funding from Connecticut Sea Grant, the U.S. Coast Guard and other federal agencies to do landmark studies on how zebra mussels and other invading plants and animals travel from one place to another. The most common method of transport, he says, is via ballast water in ocean-going ships, although the organisms can also travel between lakes and rivers on boat hulls, on aquatic weeds caught in propellers or on boat trailers, and invisibly in bait buckets in their larval planktonic form.

"I'd like to remind boaters and anglers to take some simple precautions to avoid spreading zebra mussels and aquatic weeds from lake to lake," said Balcom. "The most effective steps to take are removing all aquatic weeds from the propeller, boat trailer and other gear before leaving a launch area, washing your boat, and drying it thoroughly in the sun for several days before using it again."