Zebra mussels clog Berkshire lake

In between Flannery’s thumb and forefinger was a zebra mussel, an invasive freshwater species that has clogged pipes, fouled water supplies, and endangered wildlife across the Great Lakes.

“They are everywhere,’’ said Flannery, bobbing in the water. “You can’t go a . . . foot without seeing them.’’

Scheurer sagged. In the week since Massachusetts’s first zebra mussel was confirmed in this popular 175-acre Berkshire lake, it has dawned on business people, boaters, and others just what a disaster the mollusks’ spread could turn out to be. Divers found rocks with clinging mussels virtually everywhere they looked yesterday in Laurel Lake, and fears are growing that the nearby Housatonic River is also contaminated.

In an attempt to slow the mussels’ spread, local officials have shut down boat ramps in at least five popular Berkshire lakes; they hope to stop the mussels, which can invade boat machinery and attach to hulls, from being inadvertently transported from lake to lake.

Some fishermen and boaters said they are doubtful that closing ramps will stop the spread, because the animals can hitch rides to other bodies of water on geese or other wildlife. Indeed, officials rarely talk about wiping out zebra mussels once they take hold in a region. Their only hope is to slow the spread.

Instead of closing its ramps, Pittsfield is stationing volunteer boat monitors at two popular lakes to ensure that vessels that have been in infested waters in Connecticut and New York - and now Laurel Lake - are properly decontaminated.

“A lot of our boaters are transient; they go from one lake to another,’’ said Pittsfield Harbormaster Jim McGrath.

The mollusks, originally from Russia, probably hitched a ride to the United States on a freighter in 1988. Since then, the mussels have become the poster child for the economic havoc a foreign species can wreak in a place with no natural predators. Adult zebra mussels colonize all types of living and nonliving surfaces, including native freshwater mussels, docks, boat hulls, and even each other, forming layers up to 1 foot thick.

Power and steel plants, water suppliers, and other businesses that suck in fresh water spend millions each year in the Great Lakes region chemically treating or retooling pipes to prevent mussel buildup, according to the US Geological Survey.

In reservoirs, the mussels can make water taste bad, and their shells are so sharp that they can cut swimmers’ feet. The US Fish and Wildlife Service estimates that zebra mussels could cost billions of dollars over the next 10 years in the Great Lakes region.

The animals feed on microscopic plant life in lakes, squeezing out small fish. They can filter up to 1 liter of water a day, eventually allowing sunlight to penetrate deeper, and in many cases that allows different plants to take hold, some also invasive. The mussels have no commercial value. While they are technically edible, they are rarely eaten because they can accumulate pollutants in their bodies.

“They can totally change the ecosystem,’’ said Jim Straub, akes and ponds coordinator for the state Department of Conservation and Recreation. He and Flannery spent yesterday in the 50-foot deep Laurel Lake and today will be in the Housatonic, into which the lake’s water often spills. They estimate the mussels have been in the lake about two years, though tests have to confirm that.

The mussels are especially feared in the Berkshires because many waterways there are high in calcium and nonacidic, conditions in which the mussels thrive. If microscopic mussel larvae get into boat intake valves or even kayaks, they can hitch a ride to another lake and take hold, many officials fear. The only way to slow their spread is to get boaters and other water users to carefully wash all equipment and gear or let it dry for about a week in sunny weather, which kills the mussels.

Yet as Flannery and Straub dove for the striped mussel yesterday, the challenges of preventing its spread could be seen at the nearby state boat ramp, the only one closed by the state. A young man in a yellow kayak pushed off from shore at the boat ramp, even after several people told him it was prohibited to launch from there. When a Globe reporter asked him why he was ignoring the sign, he replied that he knew how to handle zebra mussels.

“I’m here for the sun,’’ he said, paddling off.

Later, the divers saw him leaving the lake and told him how to disinfect the boat before bringing it to another water body.

Nearby resident and boater Bill Abderhalden shook his head at the kayaker. He said he supports shutting the boat ramp until authorities figure out how widespread the problem is, but acknowledges that it is not a permanent solution.

“I grew up on this lake, and it is sad,’’ he said. “But they are not going to stop them by closing the ramp.’’

State environmental officials, who question communities’ right to close boat ramps, said they have talked to other states with major zebra mussel outbreaks and none has closed boat ramps. Rather, states use public education campaigns - Massachusetts has now launched one - to inform boaters to clean or dry boats. State officials have sent a memo to communities that oversee state boat ramps, saying they have the right to refuse access to any boat that had been in Laurel Lake, but not to close off the ramps to all boats.

Not everyone agrees. Selectmen in Stockbridge unanimously voted Saturday to close all public access via watercraft to the beloved Stockbridge Bowl “to give us time to develop a plan,’’ said George Shippey, the selectman who made the motion to declare a state of emergency there. The community also canceled about five fishing derbies over the next two months at the bowl. “We know we are doing the right thing,’’ Shippey said.

For dam owner Scheurer, it is a waiting game to see if the mussels will colonize in his water intake pipe. He bought the dam in April after its owners closed a Lee paper mill. He hoped the lake water would wind down the milelong pipe to help power whatever the former mill becomes, but he said the dam is so small it is not worth trying to fight the mussels.

“I know what it’s done in the Great Lakes,’’ he said. “To hit this installation is devastating.’’

Beth Daley can be reached at bdaley@globe.com.