2008-04-10 / Front Page

Are pesticides killing Rhode Island lobsters?

By Sam Bari

Rhode Island lobstermen believe lobster numbers are down in the Narragansett Bay because of runoff of a pesticide used to kill mosquito larvae in storm drains. Photo by Robb Roach Rhode Island lobstermen believe lobster numbers are down in the Narragansett Bay because of runoff of a pesticide used to kill mosquito larvae in storm drains. Photo by Robb Roach Rhode Island lobstermen are worried that a pesticide used to control the development of mosquito larvae is killing young lobsters in Narragansett Bay and Rhode Island Sound.

The product, sold under the trade name Altosid, is deposited in storm drains to control the mosquito population. Many of the storm drains in Rhode Island's seaside communities empty directly into the bay.

Altosid is made of methoprene, a larvicide, that when applied, reduces the number of adult mosquitoes and thus reduces human risk from mosquito borne diseases such as EEE and West Nile virus. Rhode Island lobstermen and many environmentalists oppose the use of methoprene because the chemical also kills lobster larvae.

The lobstermen argue that Maine is the only East Coast fishery where the lobster population is at acceptable, sustainable levels because, unlike other East Coast fisheries, Maine bans the use of methoprene and larvicides in its waters. Maine is also the only fishery where the lobster population does not suffer from shell disease. In all the other fisheries, Rhode Island included, lobster birth rates are noticeably below normal.

Lanny Dellinger, president of the Rhode Island Lobstermen's Association, agrees that no conclusive scientific study is available that specifically names methoprene as the sole cause of decreasing lobster birth rates and/or shell disease in Rhode Island.

"That's the point," Dellinger said. "Nobody knows. Process of elimination tells us it certainly is possible that methoprene is the cause, but we don't have scientific proof either way. We don't know if the concentration of methoprene in the bay is harming the lobster reproductive process, and we don't know if it isn't. However, it stands to reason that nothing should be introduced to any fishery without knowing the consequences."

Patrick Heaney, a Rhode Island lobsterman who has been fishing out of Newport for more than 16 years, agrees with Dellinger. In a letter to the editor of a local publication, Heaney admonished the state's Department of Environmental Management in conjunction with cities and towns across the state for dumping large amounts of highly toxic poison into the catch drains and sewers that empty into the bay. His letter was signed by 14 other local fishermen and people concerned about the welfare of the industry

"The long-term risks of this practice are becoming apparent to those who work in the lobster fishery in the state," Heaney said. "The ongoing incidence of shell disease and egg mortality, we believe, is a direct result of this environmentally questionable practice."

Rich Fuka, president of the Rhode Island Fishermen's Alliance, Chris Brown, president of Rhode Island Commercial Fishermen's Association, and Dennis Ingram, a board member of the Ocean State Fishermen's Association, all agree. Rhode Island fishermen want the state to stop using larvicide pellets in catch basins and storm drains that empty into Rhode Island waters until conclusive scientific data is available declaring the chemicals safe.

Newport City Council member Charles Y. Duncan recently sent a fax to the Newport mayor asking for a resolution to be put on the next city council meeting agenda that bans the use of any of the toxic poisons, such as methoprene, in the mosquito abatement program. He suggested that the city look to less invasive methods of mosquito control. The results of the council's decision were not available at press time.

DEM response

DEM Associate Director of Natural Resources Larry Mouradjian answered questions about the mosquito abatement program and the use of methoprene.

In an e-mail Mouradjian said that every summer DEM and the Department of Health administer a comprehensive program aimed at mosquito control. The program began in 1999. The program includes larvicide distribution to municipalities.

He also said, "Using mosquito larvicide reduces the possibility that mosquito adulticides would be needed. Mosquito adulticides do have environmental impacts as they can affect non-target organisms. Human health risks are also associated with the use of adulticides.

"Rhode Island DEM makes methoprene available to municipalities for mosquito control as well as BTI, a benign bacterium specific to killing mosquito larvae above ground.

"One half teaspoon of Methoprene pellets are distributed to most underground storm water catchment basins monthly for four months by community department of public works workers that we train," Mouradjian said.

He explained that two identical training sessions are held each spring for municipal employees. Most employees who make the applications attend a session every two years and learn about any new developments. "All municipalities in total have been trained," Mouradjian said.

He also outlined the training program. "The training entails several speakers speaking on the topics of: Pesticide usage and safe pesticide handling, mosquito larval habitats and diseases, pesticide toxicology and modes of action, and laws, licensing, and regulatory issues.

"Each community has a mosquito control contact person that is to document to DEM's mosquito abatement office the monthly applications that are made in their community. Although documentation received back by DEM is incomplete, each community receives only that amount proportional to the number of catch basins in their community."

Mouradjian explained that methoprene pellets sink, and are very unlikely to be flushed out of a basin, based on an experiment conducted by DEM in 2000. He said there was no evidence that methoprene affects lobsters in nature.

"Fish have a different structure and I know of no impacts on their developmental processes," he added.

Mouradjian stated, "Various research documents have raised questions on the potential offsite movement and impacts of methoprene and like products. Lab research has shown 'dosage' impacts on developing lobsters, which demonstrates if unnaturally high concentrations of methoprene were to occur in the presence of developing lobsters damage could be observed. Lab tests only have documented this as far as I know.

"DEM has on two separate occasions in years past consulted with URI and other scientific partners to review the scientific literature and the possibilities of damage outside the catch basins.

"Tests were done to measure the chemical concentrations seen outside the basins and all concluded with the results that no detection was determined beyond very short distances so the 'risk' was judged negligible to organisms beyond the mosquitoes in the catch basins. DEM provides very clear and definitive directions for use by the communities so that the impact work and the use are in alignment," Mouradjian stated.

When asked if the DEM is doing anything to assure that the health of the fishery is not at risk, he said "DEM will again be reviewing methoprene use to understand the alternatives products, advances in scientific data and cost/benefit to the program.

"We will provide improved directions, alternative products or other program enhancements as deemed best. Disease monitoring continues to document presence of EEE, West Nile and other critical pathogens as present in our communities and this too must be factored."

When asked about the chances of an EEE or West Nile Virus epidemic if the mosquito population isn't controlled, he said that EEE and WNV risks are higher with higher mosquito populations and added that the risk is difficult to quantify.

Jamestown has participated in the state program since its inception, but the town does not monitor specific results. "We rely on DEM," Public Works Director Steve Goslee said. "There was a public hearing before the program started when DEM came to the Town Council."

See next week's Press for the results of a University of Rhode Island study on the use of the larvacide.

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