Proposed pesticide ban oversimplifies problem

First published in Landings, March, 2014.

The Maine Lobstermen’s Association testified neither for nor against LD 1678, An Act to Protect Maine’s Lobster Fishery, in early February. The bill, if passed, would ban the use of two pesticides used to control mosquito populations in any body of water that drains into the Gulf of Maine or on land where the pesticides could enter the Gulf of Maine in runoff.

Representative Mick Devin (D-Newcastle) presented LD 1678 to the committee on Agriculture, Conservation, and Forestry on behalf of Representative Kumiega (D-Deer Isle). Devin was the sole supporter of the bill. He said Maine should follow Connecticut’s ban of pesticides methoprene and resmethrin to protect the lobster fishery, which generated $340 million in gross revenue in Maine in 2012. “We should not be doing anything that impacts [lobsters] negatively,” he said to the committee.

MLA executive director Patrice McCarron thanked the Rep. Kumiega and his co-sponsors for putting the bill forward and elevating the potential threat of pesticides to lobster and other commercial marine species, but said that the MLA does not agree with the proposed course of action or its scope. She also noted that the lack of science to inform these decisions is very concerning.

McCarron said that the outright banning of methoprene and resmethrin oversimplifies the problem and could give the lobster industry a false sense of security. Instead, she urged the committee to allow time for state agencies to conduct research along the Maine coast to understand which pesticides are in sediments and organisms and to understand the potential impacts on important commercial species such as lobster. McCarron also noted that Connecticut’s law banning these pesticides allows them to be used to prevent the spread of mosquito-borne disease such as eastern equine encephalitis; so in reality the chemicals are not banned.

Henry Jennings, director of the Maine Board of Pesticides Control, echoed McCarron’s concerns. “Banning chemicals without a careful assessment of what products will take their place is never sound policy, and generally leads to the use of higher-risk products in their place,” he said in his testimony. Jennings pointed out that neither methoprene nor resmethrin are currently used for mosquito control in Maine. He did say that if there is a mosquito-borne disease outbreak in the state, however, both pesticides might become “a vital option.”

The Maine Board of Pesticides Control has already begun work with the Maine Department of Marine Resources (DMR) to study the effects of any pesticide used in Maine. The Board and DMR will convene an Environmental Risk Advisory Committee (ERAC) and conduct a two-year study to look at pesticides along the Maine coast. “The Board has an excellent process to address such concerns—the Environmental Risk Advisory Committee, or ERAC—that brings the best scientific minds in the state together in a collaborative effort that is generally productive and is respected by all stakeholders,” stated Jennings.

In 1999, in the wake of the Long Island Sound lobster die-off , a $10 million regional research initiative was started to investigate the event’s causes. The Long Island Sound die-off coincided with an outbreak of West Nile virus and a subsequent mosquito control program in New York and Connecticut to curb adult and larval mosquito populations. Four studies conducted as part of that research effort looked at the potential role of pesticides in the die-off. The final report on the Long Island Sound research states, “Three classes of pesticides were examined: methoprene, a larvacide; malathion, a commonly-used pesticide targeting adult mosquitos; and resmethrin, a newer pyrethroid pesticide targeting adults that is more toxic but very short-lived. All three pesticides were used to combat the West Nile virus outbreak in the summer and fall of 1999, and all were found to have the potential to adversely affect lobsters.”

The study found that the Long Island Sound lobsters were severely physiologically stressed due to sustained poor environmental conditions including above-average water temperatures of 70+°F, hypoxia, increased ammonium and sulfide in bottom sediments, and severe weather fronts that caused rapid mixing of the water. These factors alone could have caused the lobster die-off, but the study concluded that a newly discovered disease called paramoebiases was the cause of the Long Island Sound lobster die-off.

In September 2011, the Connecticut Department of Energy and Environmental Protection (DEEP) tested several weak lobsters. The DEEP Web site states, “The lobster tissues (tomalley or liver and reproductive organs) were tested for the presence of three mosquito control agents: malathion, methoprene, and resmethrin. The tests showed some lobsters collected in the mid-Sound waters were exposed to resmethrin and at least one was exposed to methoprene. Malathion was not present in any of the samples.”

McCarron said that since that study took place, the tests had been run again at a different lab and no pesticides were detected in lobster tomalley. “There still is no evidence that pesticides caused the die-off,” she concluded.

While pesticides may not have caused the Long Island Sound lobster die-off, McCarron said that there is strong scientific evidence that many pesticides used in mosquito control and for other reasons have worrisome sub-lethal and lethal effects on lobster. “Given the importance of Maine’s lobster industry to our state and coastal economy, Maine must be proactive in undertaking its own studies to understand the effects of pesticide use on our commercial species.” The MLA strongly urged the committee to support the Board of Pesticides Control in completing the necessary research.