2008-04-24 / Letters to the Editor

Methoprene blame is premature

Regarding last week's news story "Are pesticides killing Rhode Island lobsters?" public health officials, too, are very concerned about the area's dwindling lobster population. However, before the newspaper and others cast blame as to the reasons why lobster numbers are down, we need to first take a hard look at the science.

Lobstermen are worried that a pesticide, used in catch basins to control the development of mosquito larvae, is killing lobsters in Narragansett Bay and Rhode Island Sound. The U.S. Environmental Protection Agency (EPA) takes these concerns seriously and has required historic testing of the larvicide methoprene, and its effects on crustaceans. A separate study conducted in 2007 in New York found that methoprene has no "significant adverse ecological impacts." In fact, more than 20 studies have shown that, when applied at recommended rates, even at rates up to 375 times the concentration found following an application at label rates, methoprene has absolutely no effect on lobsters and other crustaceans.

There is one study that claims methoprene does harm lobsters. However, that study used concentrations in excess of 500 times the maximum amount found after mosquito control applications. Using 500 times the amount of any pesticide proves very little regarding its safety at environmentally relevant application rates.

So, what's really behind the declining populations of lobsters? At this point, no one knows for sure. Valid scientific studies point to a variety of factors, such as water hypoxia, shell disease, and parasitism. Still, in the face of scientific data, groups continue to blame methoprene: it's a convenient target. In a previous report, the Press said Maine had banned methoprene and claimed that is why the state's lobsters are healthy. Actually, this is false: Maine never banned methoprene, as the Board of Pesticide Control in Maine has affirmed.

Pinning the decline upon one pesticide that has been conclusively proven to pose little or no risk does not serve to find and address the real culprit. Assigning blame to methoprene also places the citizenry at increased risk from mosquito borne disease, such as West Nile virus.

Let's work together to search for an answer to this important problem, for the sake of our environment, the lobster industry, and our community's public health. However, in doing so, let's make certain that answer is based on valid, reproducible science, rather than superstition and innuendo that fly in the face of scientific fact.

Joseph M. Conlon,

Technical Advisor American Mosquito Control Association

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