A consultant for the Southampton Town Board of Trustees told the board and a small group of Water Mill community leaders on Tuesday that the best hope for restoring the health of the hamlet’s centerpiece freshwater lake is ridding it of destructive carp—even if it means using a poison to kill all the fish in the lake.
Consultant Jim Walker said that the Trustees have a rare opportunity to rid Mill Pond of carp and restore ecological balance to the pond because of the massive fish kill there two years ago. The pond essentially lost all of its large predator fish during the mass die-off in early September 2008, particularly largemouth bass and chain pickerel. Since that die-off, population levels of carp and goldfish have probably expanded greatly. The fish, Mr. Walker said, destroy oxygen-producing plant life and stir up nitrogen-rich sediment in the bottom of the pond, helping add to the conditions that feed the large algae blooms in the pond every summer and which led to the fish kill.
“This may be a once-in-a-lifetime opportunity,” Mr. Walker said during the roundtable discussion at Town Hall on Tuesday afternoon. “If we let it go by the wayside, the pond is going to be green for a long time ... If we get the carp out, in a few short years we’d have a pond that was much cleaner and healthy and stocked with bluegills and bass.”
Mr. Walker—who helped restore two ponds off Scuttlehole Road in Bridgehampton by removing carp to let plant species return, and reintroducing an ecological balance of predator and prey species—proposed that some of the fish could be removed from the pond by net. But he said a chemical poison, called rotenone, would be needed to ensure that all of them were killed. The poison would kill other fish species as well, he admitted, but added that because the pond now does not have healthy populations of other fish—only a few species of small fish and minnows remain in any numbers—the timing is good. Rotenone has been used extensively to kill off unwanted fish species, most notably Asian carp in rivers leading to the Great Lakes.
Mr. Walker said that the State Department of Environmental Conservation would approve the use of the chemical under controlled circumstances. The small channel that connects Mill Pond to Mecox Bay would have to be sealed off to ensure that none of the poison escaped the pond waters. The shoreline would have to be secured to ensure that no animals or pets went in the water while the poison was active, a period of only about 24 hours, he said.
Several residents and Trustees said they were not in favor of using poison in Mill Pond.
“The idea of poisoning the fish in Mill Pond, with it leading to Mecox Bay and all the fish and millions of dollars of shellfish in there, I just think there are too many unanswered questions,” Trustee Jon Semlear said. “It’s a residential area. I don’t think I could support that.” Mr. Semlear and Mr. Walker agreed, however, that simply trying to catch all the carp in the 6-acre pond with nets would be impossible.
Trustee Fred Havemeyer, who oversaw an effort several years ago to rid Lake Agawam in Southampton Village of carp, said he would be in favor of an aggressive attempt to catch as many carp from the pond as possible, and to introduce large numbers of predator fish species that would feed on the carp and return a natural balance to the pond.
A report released last month by Christopher Gobler, a marine science professor at Stony Brook University, on the water conditions in the pond before, during and after the fish kill fingered elevated levels of nitrogen and phosphorus in the pond’s waters for sparking annual blooms of blue-green algae, which coats the surface of the pond with a green scum. The 2008 fish kill was caused by a cold snap that killed the large algae bloom, sucking oxygen out of the water as it decayed.
A Massachusetts lake and pond expert hired by the Trustees, Lee Lyman, has recommended that the Trustees treat Mill Pond with alum, a mineral that would bond with molecules of phosphorus and nitrogen and sink to the bottom of the pond. Adding alum would cost approximately $30,000 per treatment, twice a year, for three to five years, Mr. Walker estimated.
But Mr. Walker said that without killing off the carp, which root in the bottom for food and stir up sediments, the alum treatments would not be enough to clear the pond.
He said that finding a way to discourage thousands of geese that sit on the pond in winter would also help the situation, as goose manure adds greatly to nitrogen levels in the pond.
Tom Halsey, a farmer who lives near the pond, said the solutions proposed would mean nothing in the long run if the residents who live on the pond do not make an effort to help by reducing fertilizer use and upgrading septic systems—factors that he has blamed for the problem—like residents around Little Fresh Pond in North Sea have done.
“I can’t see the lake from my house anymore. Most of the community doesn’t even know it’s there anymore,” Mr. Halsey said, nodding to the private development that has completely blocked the pond from public view, except for a tiny stretch of Deerfield Road. “It’s a public lake ... but I wouldn’t blame you if you did nothing, because the people who live on the pond don’t want to do anything to help themselves.”
