How to rescue a weed-choked pond
WAYLAND -- On the surface, everything looks calm at Dudley Pond.
Underwater, however, there is plenty of activity. Weeds have taken over about half the pond, worrying Wayland residents.
``This year the weeds are out of control," said B. Jackson Madnick, chairman of the town's Surface Water Quality Committee. ``Over the past three years, the problem has grown steadily worse."
The 84-acre pond has been infested with Eurasian milfoil. In recent years the town has tried several methods to attack the plants, including hand pulling and drawing down the water. Residents have joined in the battle, too.
``We're looking for cost-effective ways to deal with milfoil, and we're going after long-term solutions," said Madnick, whose house is on Dudley Pond.
When he started researching invasive weeds seven years ago, he said, only 30 percent of the state had aquatic weed problems. Now, he estimates, 80 to 90 percent of the state has been affected.
In its latest tactic, the town placed weed-eating weevils in a portion of the pond last week. The weevils, which are about half the size of a grain of rice, were purchased with a $70,000 grant from the state Department of Environmental Protection.
The weevils will get a year to demonstrate their effectiveness. If the test run proves successful, they will be spread to the rest of the pond, Madnick said.
Pond advocates want to explore other antiweed tactics, as well.
The Surface Water Quality Committee, the Dudley Pond Association, and the Conservation Commission are applying for a grant from the town's Community Preservation Committee.
The Surface Quality Committee discussed the grant proposal, which calls for a two-phase program, at a meeting last week.
The first phase, estimated to cost $75,000, would involve testing three techniques: an electrically powered pond circulator, organic mats that would be placed on the floor of the pond, and the remediation of failed septic systems.
In the second phase, the town would pursue whatever was found to be most effective in the first phase.
``I think it's really challenging," said Cheryl F. Hughes, president of the Dudley Pond Association. ``We're doing a lot of research because we don't know what will work. This is the type of problem that you need to attack with various methodologies."
Madnick agreed. ``Some methods work, and 3 miles away they don't work," he said .
Herbicides are one thing that most residents and water quality committee members don't want to use. They were used in the pond in 2003, combined with hand pulling, but that has been discontinued, partly due to public health concerns.
``Over the years there's been a vocal group" against herbicides, said Steven Calichman, director of the Board of Health. ``It's the type of thing where you don't hear much from the silent majority."
Still, plenty of towns are using herbicides. So far this year, the state has approved 223 permits for chemical treatment of water, said Edmund Coletta, a a spokesman for the Department of Environmental Protection.
Herbicides yield fast results, Madnick said, but his committee is interested in techniques that may take longer to show results but would have a lasting impact.
Harvesting, essentially underwater lawn mowing, has had a significant impact in Heards Pond, resulting in the removal of hundreds of thousands of pounds of weeds, he said. ``In the end, we cut the weeds in Heards Pond by fiftyfold. We've almost eradicated the problem of weeds in the pond."
The town is no stranger to weed problems. The town borders on Lake Cochituate, where invasive plants are the subject of a similar debate.
Walkers and joggers use the path along Dudley Pond year-round. In the summer, it is a hot spot for swimmers and boaters. The proliferating weeds can pose serious safety hazards for humans in the water, alter the area's ecology, and disrupt native animals and plants, officials and activists said.
``It's not just about recreation," said Hughes of the Dudley Pond Association. ``It's about the wildlife habitat we're protecting, and there's a history to the pond, as well."
Hughes's husband, Ted, whose background is in aquatic ecology, spends hours a week hand-pulling weeds from the pond on his own.
As a diver, he has a unique perspective on the plant. ``The milfoil is just growing faster than we can pull it," said Hughes. ``Being underwater there, I see that. . . . The weeds are really out of control."