Activists Fight Methoprene Spraying

Suffolk will continue use of mosquito larvicide despite restrictions elsewhere

Despite the objections of the East Hampton and Southampton Town Trustees, the East Hampton Town Board, many South Fork residents, and one very determined activist, the Suffolk County Legislature voted on Dec. 1 to approve the use of methoprene, a mosquito larvicide, in the Department of Public Works 2016 vector control effort.

Kevin McAllister, founder and president of Defend H2O and the former Peconic Baykeeper, had addressed the Oct. 21 meeting of the Legislature’s Council on Environmental Quality, the Nov. 23 meeting of its public works committee, and the Dec. 1 meeting of the full Legislature, arguing each time that methoprene adversely affects non-target aquatic species including lobster and crabs and is unnecessary on the South Fork, where no cases of West Nile virus, which is transmitted by mosquitoes, were reported in 2015.

The Department of Public Works vector control division has been using methoprene, along with another larvicide, BTi, for several years, but its methods must be approved annually.

“Based on years of documentation I have seen, this has always been about nuisance control” and not a threat to public health, Mr. McAllister said last week. He cited a study by Michael Horst and Anna Walker in the Journal of Crustacean Biology stating that methoprene causes structural and biochemical alterations in larval and adult blue crabs. The study suggested that exposure at minute concentrations reduced the number of successful hatchings and resulted in lethargic behavior in surviving larvae.

Mr. McAllister referred to that study when arguing against the use of methoprene in front of the Council on Environmental Quality, during which he cited the Connecticut General Assembly’s 2013 ban of methoprene and the adulticide resmethrin in coastal areas. Rhode Island, Maine, and New York City have also enacted restrictions. In September, Senator Chris Murphy of Connecticut wrote to Gov. Andrew M. Cuomo asking that New York follow his state’s lead, citing evidence that pesticide runoff might be contributing to the precipitous decline of lobsters in Long Island Sound.

Dominick Ninivaggi, the vector control division’s superintendent, had attended the meetings at which Mr. McAllister testified. On Tuesday, he said the restrictions in Connecticut “were done at the request of lobster fishermen. There was no scientific evidence presented to justify it. Their own experts testified that it was not justified and not necessary, but they chose to do what they did.”

Mr. McAllister angrily disputed that assertion. “Connecticut didn’t just enact a ban because some fishermen were upset,” he said. “They went through due diligence in substantiating a legislative action that said, ‘We can’t use methoprene in coastal areas.’ Here’s a neighbor, at a state level, saying ‘We’re banning it,’ and we continue to rubber- stamp these work plans that include methoprene. Why and how is Connecticut so different than Suffolk County relative to our coastal areas?”

“What legislatures do,” Mr. Ninivaggi said, “is not really relevant to the decision-making in Suffolk County. Our decision-making is based on looking at the scientific evidence.”

Tyler Armstrong, who will be sworn in as an East Hampton Town Trustee next month would like to see all of the South Fork’s governing bodies deliver a joint message that “We don’t want this.” He believes methoprene endangers the South Fork’s fisheries and “poses a threat to our waters,” he said. Mr. Armstrong said he ran for trustee in part because “I wanted to take steps to increase the amount of shellfish, of life, in our harbors, and I think methoprene is a barrier to that, at least for species like crabs and lobsters. Also, mosquitoes are a food source, a lot of times. I feel it slows development of young fish because it takes away some of their food supply.”

“We’re concerned about nontarget species too, of course,” Mr. Ninivaggi said. “We looked at this very carefully. You have to understand. The concentrations of methoprene that end up in the environment are far below levels shown to impact crustaceans. There is a very substantial margin of safety.”

He said that based on its own assessment as well as those of the federal government and state’s Department of Environmental Conservation, the county had concluded “the risks are very minimal and provide a substantial benefit.” In fact, he said, “It’s a net plus for the program in terms of risk, because one of the things we want to avoid is having to spray residential areas. Using methoprene in salt marshes and being able to get better control reduced the number of mosquitoes reaching residential areas, reducing that treatment.” Overall acreage treated by aerial application of methoprene was 20 percent less in 2015 than in the prior year, he said. “In general, our larval control has been going down.”

Mr. McAllister remains unconvinced, and pledged to continue his effort. “I won’t ever give up,” he said, “and I am confident that at some point in time, maybe this season, methoprene will be removed from their work plan. I can assure you that I will be back before that Legislature to at least remind them, as we get closer to the season, of public sentiment.”