Ossipee — June 7, 2005 — Commercial divers waded into murky Phillips Brook Tuesday and ripped the first milfoil plant from the Ossipee Lake tributary’s weed-ridden beds.

Invasive species of non-native plants, like the spindly milfoil — which can take root from only a torn bit of leaf and bloom to clog a lake — have sent environmental officials scrambling to stop them, as infestations threaten to jump from lake to lake on boat propellers and water currents.

Tuesday’s submersion splashed off a progressive state study, pitting the effectiveness of human divers against herbicides, in the fight to halt the alien weed’s march across state waters.

New Hampshire Department of Environmental Services for the first time is matching town funds, including $5,000 from Ossipee this year, to manually reap the weed and track its rate of re-growth. The state last year would pay only for chemicals, poison that apparently left nests of rotting leaves but couldn’t kill the plant’s roots, according to selectmen and area environmentalists.

State and local officials treated the brook that flushes into Ossipee Lake’s Leavitt Bay with a low grade chemical last year, but the treatment was so ineffective, one selectmen joked, that it could have been fertilizer.

“I was really disappointed,” Ossipee Selectman Harry Merrow said Monday. “It looked like they put fertilizer in there,” he said. “In my opinion, it came back worse than what it was.”

The state uses at least two grades of herbicide to shock the weed to death, Merrow said. “One is potent and one is not quite so potent,” he said.

A higher grade anti-milfoil chemical, applied recently in a 31-acre patch of Lake Winnepesaukee too big to be hand-picked, is far too toxic for Ossipee Lake and nearby drinking water, Merrow and others said.

“The problem with (the heavier duty poison) is you cannot do it in the lake because of wells,” according to Ossipee Lake Alliance founder Susan Marks. “You have to close it down for swimming, and it’s 30 days before watering the garden and drinking.”

Marks, Alliance co-founder David Smith, and member June D’Andrea have worked tirelessly to bring professional divers like Cliff Cabral into New Hampshire after watching his hand-pulling technique take root in Maine lakes.

“In three years, no milfoil has come back to Little Sebago,” D’Andrea told the board, updating them on divers’ progress Monday.

“It’s constant surveillance,” Marks added. “But they’ve had good success, and we’re hopeful.”

“Me, too,” agreed Merrow, who said the town will likely burn the weeds Cabral’s team uproots at the town incinerator. “You can’t serve this as spinach or anything like that,” he joked.

Since its chemical treatment last year, the brook is in bad shape, D’Andrea said.

“It’s really horrible in (Phillips Brook),” she said. “Cliff said he got ear infections,” she said, then joked, “He’s got milfoil coming out of his ears.”

An algae bloom flared up, she said, possibly fed by decaying milfoil that had built up on the banks of the brook.

“It looked like nests stuck up on roots of trees on the sides,” she said, grimacing. “The only thing he’s concerned about,” she said, “is the chemical they did treat the brook with last year, chemicals still in the sediment.”

D’Andrea said Cabral this time will have a helmet between him and any chemicals that might still mix with the soil, as well as the creepy crawlies.

“The brook is very creepy … snapping turtles and water snakes,” she said. “He will be 100 percent water tight.”

Ossipee Lake is the first site in a cautious Department of Environmental Services pilot program to rate the effectiveness of divers like Cabral against conventional chemicals, according to Marks.

“We’re the first site in New Hampshire being tested,” she said. “They are testing the two against each other, that’s why they are doing the harvest study … to see how much comes back, and when it comes back.”

“I’m hoping, they’re going to see a tremendous effectiveness to this hand-harvesting, and will be willing to dump more money into it,” D’Andrea said.

The Alliance has also aligned lakeside homeowners against milfoil, and helped establish watchdog “weed-watcher” programs on area waters. The group is also working closely with ramp owners, to curb spread of the weed by unwary boaters.

With the Alliance’s help, infestations have been treated in Phillips Brook, Leavitt Bay, Danforth Pond, Danforth Brook and the Ossipee River, according to an Alliance press release.

Homeowners and the town of Freedom collaborated last year to hand-harvest milfoil in Freedom waters. Tuesday’s splashdown in Ossipee’s Leavitt Bay marked the first state-funded harvest by divers.

Divers will be hand-pulling weeds this week from the bottom of about 5 acres of Phillips Brook and Leavitt Bay. Volunteers with or without boats are encouraged to help skim floating, pre-pulled weeds. The group will launch from the Remle Road boat ramp, off Leavitt Road, which is off Route 25. D’Andrea can be reached for information and directions at 539-1643.