Foiling milfoil

HUDSON – If milfoil were a dinosaur instead of a water-borne weed, it might be a velociraptor.

Ken Warren, a water pollution biologist with the state Department of Environmental Resources, tells of a small lake in the town of Brookfield so contaminated by milfoil that the water was drained out in a desperate attempt to kill the plant.

Soon after the water was restored to the lake, the plant returned, Warren said. Seeds, which had remained dormant and protected in the lake-bed mud, sprang back to life.

“It was like – what was that movie? Like ‘Jurassic Park,’ ” Warren said. “Nature will find a way.”

As far as Hudson’s 40-acre Otternic Pond, residents hope the plant will soon become as extinct as the movie’s man-eating raptors.

Warren and DES colleague Scott Ashley pushed off into Otternic on Friday morning in a 13-foot Boston Whaler outboard motorboat.

Their mission: to map the extent of milfoil contamination using global positioning satellite technology and a special computer program.

“Today, we’re going to be mapping the weeds,” Warren said. “We know we have milfoil here. So do a lot of lakes in the state.”

When Warren and Ashley arrived in the morning, they were greeted by Curt Laffin, a member of the Friends of Hudson Naturalham, who lives near Otternic Pond and belongs to a loosely affiliated group concerned about the water body’s health.

Milfoil is a transplant from Europe and Asia that has been choking native plant species out of a growing number of lakes and ponds in the state. The nuisance plant has been found in nearly 60 of the state’s roughly 900 lakes and ponds, according to the DES.

The problem with Milfoil is it spreads so easily, usually by attaching to boat propellers in an infected lake. If a small strand of milfoil falls off a boat into a lake where the plant hadn’t been found, that lake soon might also become contaminated.

Milfoil first showed up in New Hampshire in the 1960s, Warren said.

“We suspect it started at (Lake) Winnipesaukee. That seems to be where the mother lode is,” he said.

The state is making “some headway” at controlling it, primarily using chemical treatments, but the weed is still present in Winnipesaukee after four decades of efforts to eradicate it, Warren noted.

At Squam Lake, milfoil has been found at depths of 25 feet. DES biologists figure that’s about as deep as it will grow.

That’s also probably deeper than the deepest part of Otternic Pond, where it didn’t take long for the biologists to figure out there was a problem.

“It’s a forest out here,” Warren said.

Not all of the pond weeds Warren and Ashley encountered were milfoil. In fact, many were native species common to lakes and ponds throughout the state.

Otternic is a drainage basin for the area to the south that once included Benson’s Wild Animal Farm. It’s a dying pond, losing more and more of its area each year to encroaching swamp, Warren said. The natural evolution of ponds and lakes is that they grow smaller, fill in, and eventually become first swamps, and then fields.

But the process can be hastened by man’s tampering, and by becoming clogged with aquatic weeds.

Otternic still is picturesque. Stunted sugar maples dot the shore across from the boat launch off of Highland Street. In areas not shaded, the pond reflects the deep-red leaves of autumn. Wood ducks skim the water. Surface ripples – showing where fish rise to grab an insect snack – sporadically appear and dissipate like they were caused by raindrops.

“It’s so nice here in the spring because there are none of these weeds. It’s so open and clear,” Cunningham said.

The pond has plenty of fish, including bass, pickerel, crappies, kibbies and horned pout, and Cunningham and other nearby residents enjoy fishing here – to the extent they can do so without snagging their lines on weeds.

“Supposedly, a pond this contaminated reduces surrounding property values by 10 to 15 percent,” Cunningham said.

“It’s been this way since I moved here (five years ago), but I was told this isn’t how (the pond) really is,” he said.

As the boat circled, the feathery weed, kelly green in the sunlight, is easily seen beneath the surface. In some places milfoil dominated, looking like fields of aquatic ferns. In other place strands could be spotted nestled among the duller native species.

The biologists also found something unexpected: the presence of fanwort, another exotic nuisance plant that has been a problem in Robinson Pond.

“You’ve got two in there now. That’s not good,” said Warren, a 33-year DES veteran. “There should be even better competition. You’ve got two exotics that are going to fight it out.”

That’s the problem with invasive weeds – towns also have to fight it out to get a share of limited state money available for the chemical treatment used to fight the contamination.

There are lots of lakes in New Hampshire, but little money. About 20 to 25 towns have placed money into escrow, saving to pay for the work to be done by private contractors rather than waiting for state money, Warren said.

“A lot of people love or hate me, depending on where the money goes,” he said.

By Friday afternoon, Ashley, whom Warren described as both a biologist and a “computer guru,” had completed the map, which showed widespread milfoil colonies and a few fanwort populations.

But the map doesn’t mean funding will follow, given the competition.

Laffin said some neighbors near the pond have taken on the role of becoming “squeaky wheels” to get some of the state’s funding grease.

If it takes several years for funding to come through, that would be fine for the milfoil. It will still be there, waiting.

Once a lake becomes contaminated with milfoil, “it never leaves,” Warren said.

“We’re trying to predict Mother Nature, and that’s never been done yet,” he said of the state’s efforts to keep on top of the contamination.

“It’s hard to predict the behavior of plants.”