Scientists Puzzled Over Dying Lobsters

August 4, 2000 -- Twelve days ago, Joe Fink named his newborn baby girl after his fishing boat, Rebecca. This week he had to put his daughter’s namesake up for sale.

“I hated doing it. I built it myself,” says Fink, who is president of the Western Long Island Lobsterman Association. “But I realized I had to. Right now there’s just no future.”

Fink is one of the hundreds of lobstermen in New York and Connecticut who have been forced to abandon lobstering as the insect-like crustaceans disappear from Long Island Sound. State officials estimate that 11 million lobsters or 90 percent of the entire population died in the Sound last fall. This summer, the main money-making season for most lobstermen, the crustaceans are again a no-show.

The losses are significant since the Sound usually generates about $45 million in annual sales and is the nation’s third-largest lobster source, behind Maine and Massachusetts.

“It’s way worse,” says Jeff Carbone, a lobster distributor based in Huntington, New York, who says he’s taking in 80 percent fewer lobsters than last summer. “I had 25 lobstermen supplying me, now I’ve got eight. These guys just don’t want to take any chances.”

So Far, One Parasite

The cause of the die-off has befuddled scientists ever since lobsters started disappearing in large numbers last September. The only definitive finding so far is that of a protozoan parasite that University of Connecticut veterinary pathologist Richard French located in all 150-200 lobsters he sampled from the Sound last fall.

“It would be unusual to see such a massive mortality associated with a single parasite,” says French. “But it’s not out of the question.”

But many lobstermen think a single parasite is hardly the only problem. They are convinced the die-off is related to mosquito sprayings in Connecticut and New York. Both states border the Sound and have conducted sprayings to prevent the spread of the mosquito-borne West Nile virus. Lobstermen associations from the Long Island Sound region are now working on a class action suit that they expect to file against New York and Connecticut by the end of the summer.

“We’ve done everything by the book,” says Fink, “and our livelihood was taken away from us. We feel the problem was manmade and we need to be paid for our suffering.”

At least one scientist working on the problem is starting to think the lobstermen’s suspicions may be right.

Vulnerable Like Insects

Robert Bayer, director of the Lobster Institute at the University of Maine, examined sickly lobsters from the Sound last September, looking for bacteria and viruses. When none turned up, Bayer then tested the lobsters’ systems for traces of the pesticide malathion, which was sprayed in New York last summer in an effort to keep mosquitoes carrying the West Nile virus at bay. That also turned up negative. But now Bayer says he thinks pesticides may be a cause and the parasite might be a secondary problem for already stressed lobsters.

“We didn’t find any malathion in the lobsters we had, but that doesn’t mean it wasn’t there,” says Bayer.

Bayer points out that New York and Connecticut have used at least two other kinds of pesticides besides malathion. The states have sprayed low concentrations of resmethrin and sumethrin. Both are synthetic pesticides similar to a natural pesticide produced by chrysanthemum flowers that kill insects by attacking their nervous systems.

The problem, Bayer says, is mosquitoes and lobsters are very similar.

“Just hold a lobster and a spider side by side and you see the similarities,” he says. “Almost anything that will kill an insect will kill a lobster.”

Lobsters and insects are both arthropods and both have external skeletons, compound eyes and semi-closed circulatory systems. Most importantly, they share similar nervous systems made up of nerve cell clusters called ganglia. Because they share the same kind of nervous system, Bayer believes they are equally susceptible to insecticides.

In laboratory tests, Bayer placed healthy lobsters in tanks of water with minute traces of pesticide inside. The lobsters’ reactions, he says, were the same as insects dying from pesticide exposure.

“They get very ticky and spastic and then they die,” he says. “And we’re talking traces of pesticide measured in parts per billion.”

Carbone says he knows firsthand how sensitive lobsters are to insecticides. A few years ago, he hung an insecticide-coated strip of tape in his company’s storage area to keep away flies and insects. Two days later, not only had the insects died, so had the dozens of lobsters in his storage tanks.

“And that was just hanging in the air,” he says. “It wasn’t even in the water.”

States Say Sprays Insignificant

But Paul Capotosto, the supervisor for mosquito management in Connecticut, says the levels of insecticide the state has sprayed are too low to even register in runoff to local waters. He says that workers mix the insecticide with mineral oil and then spray one to two ounces of the mixture per acre.

“This stuff is toxic for animals if you dump a five-gallon pail of it in the water,” Capotosto says. “But the dosage comes down to the point where you can’t even detect it.”

Still, Bill Smith, head of the nonprofit conservation group Fish Unlimited, claims insecticides have been detected in the dying lobsters. His group sent samples of infected lobsters to ETI Environmental Laboratory in Fairfax, Virginia, last October. They recently received the first set of results back from the laboratory and Smith says, “They verify our concerns that pesticides may have played a primary role in the death of the lobsters.”

Fish Unlimited will be supplying lobstermen with data when and if they file a suit against New York and Connecticut in coming months.

A Slew of Possible Causes

Scientists point out there are many other environmental factors in Long Island Sound that may have weakened the lobsters. Dredging materials, which are routinely dumped near the waters of Long Island Sound, carry oils and fertilizers. These can feed bacteria, which then consume oxygen and release toxic by-products. Lobsters, which crawl on ten legs and scour the ocean floor for food, are particularly vulnerable to picking up toxic compounds from the sediment.

As Richard Robohm of the National Marine Fisheries Service lab in Milford, Conn., says, “A fish can swim away, but lobsters can’t get out of the environment fast enough.”

Two new grants, a $125,000 research project from the Environmental Protection Agency and a recent congressional grant of $6.6 million should help scientists sort out which factors have led to the die-off. But as French says, “It will be some time before the money is made available.”

And, at this point, answers aren’t going to do much for lobstermen like Fink, who has taken up digging for clams to earn some income and is trying to figure out a whole new career.

“The bills keep coming in and Rebecca and our other kids keep growing,”he says. “It’s a downward slide right now.”