Water chestnut removal plan to be reconsidered

SHARON — Invasive management efforts on Mudge Pond began in earnest last week, though the removal team quickly realized that more intensive methods may be required to deal with what is a growing problem on the lake.

The Mudge Pond Association, a community lake protection and management organization formed earlier this year, received approval from Sharon’s Inland Wetlands and Watercourses Commission on July 14 to hand pull invasive water chestnut from the lake. The approach was notable in that it omits the need for herbicide use, a contentious topic in aquatic invasive species management but a route that many other lake protection groups have taken to combat their own infestations.

On July 31 and Aug. 1, a team led by Matt Vogt of New England Aquatic Services floated out on a pontoon, a paddle board and a kayak to begin the process. The team found far more of the invasive waterweed than anticipated, and in a complex environment where plentiful lily pads shielded many floating tendrils of water chestnut.

Vogt said that after two days on the water, the team realized that the issue had progressed to the point it “needs a different sort of attention.”

Water chestnut was identified as a first target by the Association because it is less established in Mudge Pond than the other invasive plants, and as such is primed to be dealt with before it becomes a more pervasive issue.

A study published earlier this year on the lake’s ecological health and water quality identified five colonies of water chestnut in the pond, and while New England Aquatic said they don’t have reason to believe it has extended beyond those colonies, the density of the plant where it is growing in complex environments will require more than hand-pulling to be dealt with effectively. Vogt recommended a mechanical harvester, which is a powerful but less precise removal method, to Mudge Pond Association Chair Andrew Cahill as a means to eliminate the plant without resorting to herbicides.

“Trying to pick around the other plants is going to be beyond hassle — it’s going to be detrimental,” said Vogt, explaining that attempting to locate each plant by eye will inevitably lead to missed weeds.

A mechanical harvester clears all the floating biomass from an area, which would include native lily pads, but Vogt affirmed that lily pad roots grow back. Crucially, the water chestnut reproduces from its floating leaves, so clearing those from the pond will prevent future growth since it does not grow back from its roots.

Cahill said that he’s been in conversation with the Land Use Office about amending the approval to include mechanical harvesting, but may have to return before the IWWC with a new application before the work can begin.

Water chestnut is just one of five invasive species identified in the report, which was conducted between April and December of 2024. The report recommends that the more established populations — the most pervasive of which are Eurasian milfoil, curly-leaf pondweed and fanwort — be treated with herbicides.

Cahill said that he recognizes the community’s reluctance to use herbicides in Mudge Pond, and feels ambivalent about the prospect himself. “I was paddle boarding on the lake yesterday and, like, do I want to be paddle boarding in some kind of herbicide? I don’t know,” he said in a recent phone call.

He recognizes, however, that the topic is becoming unavoidable. “Yesterday’s meeting was eye-opening for me,” he said, referring to the Saturday meeting of Salisbury’s Twin Lakes Association, where invasive management professionals advocated for herbicide as the only effective path to an invasive plant free lake.

Cahill said he hopes to organize a meeting in Sharon where experts and residents may discuss the topic in a constructive public format, and let the community decide how best to address the problem.

“This is what the experts are saying, and this is what the other lakes are doing,” he said. “What do we think?”