Wednesday August 10, 2011

Zebra mussels have been detected in the Housatonic River as far downstream from Laurel Lake in Lee as the Connecticut state line and beyond, according to a report from Biodrawversity, an Amherst-based consulting firm.

As of last summer, the invasive mollusks' downstream presence extended only as far as Stockbridge.

Senior ecologist Ethan Nadeau, who owns Biodrawversity, measured the downstream migration during tests this summer. The mussels were carried from the lake into the river by Laurel Brook, he said. Biodrawversity confirmed the presence of zebra mussels in Laurel Lake in 2009.

Nadeau has alerted the Housatonic Valley Association, said Dennis Regan, the Massachusetts director of the organization.

"There is no natural enemy of the mussels, so we can expect them to keep on spreading," Regan said.

Regan pointed out that a mussel can produce 1 million offspring a year -- microscopic, planktonic larva called veligers. In those large numbers, the adults grow and attach to boat hulls, outboard motors and propellers, and they cluster and clog pipes and foul other objects in the water. They're also sharp enough to cut bare feet.

In an email message, Nadeau identified infestations of adult mussels at multiple locations along the river, including dams at the Willow and Eagle mills in Lee, the Glendale section of Stockbridge and the Rising Paper Mill in the village of Housatonic, part of Great Barrington.


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"We knew it was inevitable," said Regan, "and it happened a lot more quickly than we expected, but that's the nature of the beast. Once they're found, they're here to stay and all we can do is delay their spread elsewhere."

On a positive note, state testing of Stockbridge Bowl shows there are no zebra mussels, said George Shippey, who chairs the Stockbridge Conservation Commission and the town's Zebra Mussel Committee.

According to a memo from State Department of Conservation and Recreation Ecologist Tom Flannery, visual, snorkel and below-surface surveys on July 27 detected no adult or juvenile mussels anywhere in the lake.

Shippey credited the state-hired monitor, William Gale of Cheshire, as well as the town's paid monitors who are on duty at the public access ramp off Route 183, from 7 a.m. to 7 p.m. seven days a week, for keeping the lake free of invaders. The town monitors are paid through a $14,000 donation from Kripalu and the Stockbridge Bowl Association.

Funded by $50,000 approved at Town Meeting in May, the town is putting out to bid construction of a boat wash at the ramp, expected to be completed by next spring, Shippey said.

At Laurel Lake, the Lee Boat Wash is open at the public-access ramp off Route 20, bolstering a monitoring program in place since May. But the lake, shared by Lee and Lenox, already is heavily contaminated.

"Those mussels are getting bigger and bigger, coating the side of the dam," said Regan.

"Once you get zebra mussels, there's no known remedy to get rid of them," Shippey warned. "That's why we're so vigilant. They affect the natural ecology of a lake, clog up boat engines and eventually can affect property values."

Lakes are vulnerable to the mollusks if the water has high levels of acidity and calcium and a hard bottom, Shippey said. Stockbridge Bowl has two out of three factors, but has a soft bottom. Combined with the monitoring program, that reduces the risk.

No other lakes in Berkshire County have been identified as contaminated thus far. Federal and state grants worth $71,000 have funded eight full-time boat ramp monitors at several lakes as well as the portable wash station at Laurel Lake and another on West Housatonic Street in Pittsfield.

State officials have described Berkshire County as on the "front lines" of the zebra-mussel invasion. Also being monitored are Lake Buel in Monterey, Richmond Pond and Cheshire Lake.