Trustees Fret About Blue Crabs

Weed harvester blades could harm creatures

An aquatic weed harvester that is to begin removing macroalgae from Georgica Pond this month is of concern to the East Hampton Town Trustees, who own and oversee many of the town’s waterways and bottomlands on behalf of the public.

At their meeting on Monday, the trustees discussed the potential impact of the harvester on crabs and other aquatic life in the 290-acre salt pond, which has had dense cyanobacteria blooms, attributed to excessive nitrogen and phosphorous, in the last two summers. The trustees banned crabbing and fishing at the pond for much of those summers, and warned the public against exposure to its waters.

Use of the harvester to remove macroalgae is one component of a remediation plan developed by the Friends of Georgica Pond Foundation, a group of property owners. Macroalgae is believed to store excessive nutrients; it is hoped that its removal will cause dramatic reductions in nitrogen and phosphorous, which are needed to restore the pond to health.

In collaboration with the town, East Hampton Village, and the trustees, the Friends of Georgica Pond Foundation has also applied for permits to dredge the mouth of the pond and remove bottlenecks of sand and phragmites that have massed in Georgica Cove. The foundation advocates more frequent opening of the pond to the Atlantic, which the trustees usually do twice a year in the spring and fall, and the installation of permeable barriers on property surrounding the pond to intercept nitrogen from reaching groundwater.

The group engaged Christopher Gobler of Stony Brook University’s School of Marine and Atmospheric Sciences, who has been monitoring waterways for the trustees since 2013, to study the pond and make recommendations for restoring it. 

  “My only concern is if this thing isn’t operated properly, it could act more like a dredge. I don’t think that was anybody’s vision,” Jim Grimes, one of the trustees, said. The effort would probably produce positive results, he said, “but are we just going to turn them loose?”

“There are crabs, and stuff that might not get along with the reciprocating blades” of the harvester, Mr. Grimes said. “I don’t want to say no, but we should monitor this thing.” He recommended that he and a colleague observe and perhaps ride on the harvester while it is in operation. “We’ve got to see what the impacts of this thing are on the bottom, and if there are any negative impacts, we’ve got to be prepared to step in and adjust the methodology.”

Tyler Armstrong agreed, saying that, in a video of a harvester operating elsewhere, “it seems to turn the bottom more” than he expected.

Richard Whalen, the trustees’ attorney, said he had spoken with a bayman who suggested that the harvester was only “a high-tech way to deal with an issue that historically you’d deal with by flushing the pond,” which increases salinity and quickly dissolves algal blooms. But Bill Taylor called the foundation’s plans “well thought-out and comprehensive,” with the macroalgae harvesting “just a small part of it.”

Mr. Grimes agreed. “We’re dealing with surface water from road runoff, from private residences, failed septic systems. A bunch of things have to happen” if the pond is to be restored to health.

The East Hampton Town Board adopted a resolution allowing the harvester’s use on weekdays, for seven- and-a-half hours a day, through August.