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Invasive Asian clam species spreads in Lake George; rest of the Adirondacks watching

October 20, 2012
By CHRIS KNIGHT - Senior Staff Writer ( , Adirondack Daily Enterprise

Lake George has long been an invasive species battleground, but the ongoing and costly two-year-old fight to rid the lake of Asian clams has quickly become its most critical campaign yet.

Hundreds of thousands of dollars have been spent so far, and even more money is being sought, to eradicate the fast-breeding mollusks, which have now been found in eight different areas on the 32-mile-long lake known for its crystal-clear water quality.

As it grapples with how to further prevent the spread of Asian clams and other aquatic invasives, the Lake George Park Commission, the state agency charged with protecting the lake, is considering a bold step - making Lake George the first water body in the state where boat inspections and decontamination are mandatory.

Article Photos

A worker hands a roll of plastic mat to a diver to be placed on the floor of Lake George in 2011.
(AP Photo — Mike Groll)

Officials say the aggressive approach is warranted because the stakes are so high. Many point to what's happened in Lake Tahoe, where Asian clam infestations have hurt tourism, recreation and the environment.

"Unquantifiable, long-term and large-scale ecological, social and economic impacts could occur if Asian clams become established at sufficient densities in Lake George," state Adirondack Park Agency Deputy Director Rick Weber reported to agency commissioners last week. "It's a severe concern and threat to the long-term health of the lake."

It's not only an issue for Lake George. The prospect of Asian clams spreading to other lakes in the Adirondacks has many people throughout the Park concerned, and they're closely following what's happening in Lake George.

"They are at the forefront," said Hilary Smith, director of the Adirondack Park Invasive Plant Program. "Lake George is really setting precedent in terms of how we address invasive species."



Asian clams were first discovered in August 2010 just offshore of Lake George village, in the lake's southern basin.

In October of that year, the APA approved a permit allowing divers to place large plastic mats, called benthic barriers, on the bottom of the lake. Held in place by sandbags and rebar for up to 45 days, the mats are designed to smother the thumbnail-size clams, starving them of oxygen.

The treatment area near the village covered about three-tenths of an acre in the fall of 2010, but it has now grown to roughly 25 acres, Weber said.

"Initially it was spots in this area being treated, and progressively it has moved into one contiguous area," he said. "The treatments are effective, but it's not absolute. This species reproduces very quickly and spreads very quickly."

In the summer of 2011, clams were found in three more areas north of Lake George village in the town of Bolton: a 2.3-acre infestation near a marina in Sawmill Bay, a 0.7-acre site in North Middleworth Bay and a 2.8-acre infestation in Boon Bay. All were treated with benthic barriers.

In mid September of this year, a comprehensive survey of the Lake George shoreline was performed over two weeks by a coalition of government, civic and environmental groups dubbed the Lake George Asian Clam Rapid Response Task Force. More than 30,000 sieves were taken at hundreds of sites. Four new Asian clam infestations, each relatively small in size, were discovered.



Park Commission Executive Director Dave Wick said the plan is to eradicate the four new sites and contain the four existing sites using benthic barriers, which he said are the only proven technology to control Asian clam populations

"It's a tremendous level of effort," Wick told APA commissioners last week. "We hired a dive crew. Underwater you roll out the mats. We have prison crews making 15,000 sandbags. We've ordered 100,000 pieces of rebar. We have another $70,000 worth of mats coming in next week."

AuSable Forks-based Aquatic Invasive Management is heading up the eradication effort. The Enterprise talked with AIM co-founder Andrew Lewis this week via cell phone from a boat in Log Bay, one of the four new infestation sites in Lake George, where he was overseeing a team of seven divers.

"We've got a whole bunch of mats down, and we're adding sandbags to them," Lewis said. "Our first priority is to wipe out the new areas, then move into the old areas that still have clams persisting."

While most people support the management program, it hasn't been completely embraced. Some shoreline property owners, particularly hotel and motel owners, are frustrated with having all these mats, sandbags and rebar in their beach areas.

"Some people are focused on the short term, and they need to have a quality beach for their bottom line," Lewis said, "but a lot of people definitely understand the need for it, and the fact that it is a legitimate problem that will affect them down the road if nothing is done."



Getting rid of Asian clams isn't cheap. Wick said it costs about $40,000 an acre to treat the infested sites.

The task force estimates continued treatment of all eight locations will take $1.1 million. So far, it has raised about $430,000, including $270,000 the Warren County Board of Supervisors contributed earlier this month. The funds came from the county's tax on hotel and motel room stays.

"The supervisors are extremely concerned," said Fred Monroe, town of Chester supervisor and executive director of the Adirondack Park Local Government Review Board. "They know that Lake George is the most important environmental asset we have in that region of the Adirondacks, and they also know it is the most important economic asset."

The cost of the Asian clam fight is also taking money and resources away from other invasive species management efforts in the lake.

"We've been fighting milfoil in Lake George for 26 years, and we've gotten it to the point where there's only 14 dense beds left and they're fairly small and manageable," Wick said. "We're almost there, but our eye is on the ball so much with Asian clam that milfoil is taking a back seat."



What exactly are people worried about? What can Asian clams do to a lake? Wick points to what's going on in the southeast basin of Lake Tahoe, located in the Sierra Nevada along the border between California and Nevada, where Asian clams were first detected in 2002.

"Lake Tahoe didn't get on the problem when they should have, and they admit that openly," Wick said. "It was in Tahoe for about two years before they decided to act, and it is unfortunately now well beyond their ability to manage.

"Asian clams come in, and they reproduce prolifically. You go from a batch of 1,000 to a million to a billion to a trillion. Ultimately what you end up with is completely covered shorelines 2 to 3 inches thick in dead and dying clams and shells. When those clams die, they excrete nutrients, and those nutrients cause algae blooms, and all of a sudden we have an algae problem. This is what we're trying to avoid."

Water quality in the southeast portions of Lake Tahoe has declined by about 30 percent over the last five years, Wick said. A 2009 study estimated the potential combined impact of Asian clams on tourism, recreation, property values, water supply and maintenance at more than $20 million annually.



Education, public outreach and prevention are seen as key steps to keeping new invasives out of Lake George.

There is a lake steward program, run by the Lake George Association, at the six major launches on the lake. Stewards inspect boats for invasives and educate boaters about preventing their spread, but it's a voluntary program and doesn't cover all of the roughly 100 launches on the lake.

That's part of the reason why the Park Commission is now considering making boat inspection and decontamination mandatory.

How would that work?

"If you come from outside Lake George, we would have regional inspection stations," Wick said. "If you pass inspection, your boat would get zip-tied to your trailer, you'd go to the launch, clip it off and there you go. If you don't pass the inspection, your boat would get decontaminated (using a power washer with hot water)."

Wick said mandatory boat inspection and decontamination has been implemented in Lake Tahoe and other areas around the country. It was also recommended by the LA Group, a consulting firm hired by the Park Commission to analyze its invasive species prevention options. And the public, based on the feedback at a series of recent meetings, seems to support the idea of mandatory inspections, much to Wick's surprise.

The Park Commission is expected to decide next month what course of action to take. The biggest challenge, not surprisingly, would be how to pay for it. Setting a $20 to $30 inspection fee, raising boat and dock fees or creating a special tax assessment district are some of the ideas being considered.


Beyond Lake George

When the idea of mandatory inspection and decontamination was presented at last week's APA meeting, several commissioners noted that it would do nothing to prevent the spread of invasives in Lake George to other Adirondack water bodies.

Wick said it's just too costly to try to decontaminate every boat that comes out of the lake.

APA Commissioner Sherman Craig said that's disappointing.

"It sounds to me like every little lake and their group is going to be concerned just about theirs and not someone else's," he said. "That's why I think a statewide response and enforcement is extremely important."

In a phone interview this week, Wick said the resources to manage Asian clam infestations are beyond the scope of the average lake association or most municipalities in the Park.

"The only reason we're able to do what we can is there's such a strong consortium of people interested in Lake George," he said. "We have a lot of folks coming to the table, whereas if that happens in Saranac Lake, Lake Placid, they might not have the financial resources to get on it like we have."

Could Asian clams have already spread to other lakes and rivers in the Park? Smith, who lives in Saranac Lake, said it's possible.

"We only know of Asian clam in Lake George right now, but that doesn't mean it isn't elsewhere and we just haven't been looking for it," she said.

Smith said her organization is taking several steps to keep Asian clams at bay, including training its volunteers how to identify them when they're surveying lakes and ponds for other invasives.

"I think it's very worthwhile for us as a region and as a state to look at Lake George for lessons learned on how to do a better job with prevention," she said. "We can't afford to continue to have new invaders enter our systems. We need to shift that paradigm to being more proactive with prevention than reactive with management."


Contact Chris Knight at 891-2600 ext. 24 or



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