The Department of Energy and Environmental Protection has confirmed the presence of pesticides in Long Island Sound lobsters — albeit a very small sample — for the first time since the crustaceans began their precipitous decline in 1999.
The findings are a surprise to the scientific and environmental communities, which have generally thought that warming water in the Sound was causing the die-off. The commercial fishing industry, however, has long pointed its finger at pesticide runoff because the lobster decline coincided with the West Nile Virus outbreak and the use of mosquito sprays to combat it.
“I’m sure there are a couple of fishermen who’ll say, ‘I told you so,’” said David Simpson, the director of Marine Fisheries at DEEP. “I was pretty surprised; I was expecting no pesticide residue at all.”
Simpson said even with the pesticide findings, Long Island Sound lobster posed no health risk. The pesticides were found in lobster organ tissue, not meat, and in any case the levels were below what is considered harmful. And with lobster hauls at historic lows, the likelihood of actually buying a Connecticut lobster — while higher in this state — is still low.
Lobster landings in Long Island Sound dropped from 3.7 million pounds in 1998 to 142,000 pounds last year. That period was also marked by warming water trends and a clear shift from colder water species to warmer water ones in the Sound.
Warm-water fish such as striped bass, summer flounder, scup and butterfish increased while cold-water species such as winter flounder, Atlantic herring, winter skate and lobster seemed to move north.
Testing consistently showed no presence of pesticides. Until now.
Advances in testing technology that could detect concentrations of substances one-tenth the size of that tested previously prompted DEEP’s Marine Fisheries Division to partner with the University of Connecticut’s Veterinary Medical Diagnostics Laboratory to try testing again last September.
Ten lobsters, nine weak ones and one healthy one, were tested for Malathion, methoprene and resmethrin. All three chemicals had been used to combat mosquitoes, though less so recently. The state’s anti-mosquito efforts now center on nonchemical bacterial products that target mosquito larvae.
The results showed no Malathion in the lobsters. One tested positive for methoprene — which is used to inhibit growth of insects, and there were three positive tests for resmethrin, including in the seemingly healthy lobster.
“Honesty, these results are completely puzzling to me,” said Bradford Robinson, supervising environmental analyst in DEEP’s pesticide management program. “It’s a very head-scratching result that has us all kind of baffled.
“I don’t think it’s a smoking gun.”
Neither does Simpson. “I haven’t learned anything new that changes the opinion that stressful water temperature in the fall is the most likely cause of the mortality we’ve seen,” he said, referring to the historical death of lobsters when water in the Sound is at its warmest.
Leah Schmalz of Save the Sound, a program of Connecticut Fund for the Environment, said she was intrigued by the initial pesticide findings.
“The theory has been floating around for quite some time, but this is the first real proof,” she said. “I was in the ‘increased water temperature is the leading cause of stress and mortality’ camp, and thought that perhaps other factors were compounding that impact. While it is entirely too early to say, this finding has me wondering if ‘perhaps’ we had it backwards.”
Rep. Terry Backer, D-Stratford, said in a statement that the findings “reinforce our contention that the use of methoprene and other ultra toxic pesticides in our waters for the purposes of killing mosquito larva is dangerous and reckless.” He called for the re-introduction of legislation that failed this year that would have curtailed its use.
DEEP now plans more extensive testing beginning this summer. It will include testing for additional pesticides in a much larger sample of lobsters as well as testing of water temperature and contamination. Robinson said he would recommend looking for the widely used pyrethroid family and insecticides similar to Malathion.
He also recommends testing northern water lobsters from Maine for comparison.
He and Simpson point out there are many questions, including if the timing of last year’s testing — after Tropical Storm Irene resulted in large amounts of runoff into the Sound — was a factor.
“Will we find it again?” Robinson asked. “Is this an anomaly?”
DEEP expects its first results this fall.
“This study may finally give the region something solid to work from,” Schmalz said.