Long Island Lobsters
Mysteriously Dying -
Plum Island Link?
By Amanda Onion
(Note - During our 10-25-99 program on Plum Island, researcher Patty Doyle disclosed that a major undersea trench had recently been dug in the seabed from the mainland to Plum Island to lay power and/or telecom cabling. It was theorized that this digging might have disturbed and dislodged toxic materials. The program is available in our Archives.)
NEW YORK - Lobstering can be "a very weird industry," according to John Carbone, a lobsterman based near Huntington, New York.
Carbone recalls a time ten years ago when he and others were daily hauling up 300 pounds of lobsters. Then one day, the lobsters stopped appearing and crabs were filling the traps. The following morning, the crabs had vanished, but the lobsters were back.
"It was like it never happened," he said. "There's just no figuring it out."
This season, the Long Island crustaceans have posed another, more troubling mystery.
Starting in September, lobstermen began hauling traps full of dead and dying lobsters off Long Island Sound. There was no sign of odd coloring or shell deterioration in the dead lobsters and the dying lobsters displayed no symptoms besides lethargy.
Carbone, who has stopped taking his boat out for now except to maintain his traps, calculates he was losing at least 10 percent of his catch. Marine officials in New York and Connecticut estimate the plague has killed off tens of thousands of lobsters and describe it as the worst to hit Long Island Sound in nearly a decade.
So far, no one knows why the lobsters are dying.
"There's no smoking gun and we don't have a good clue as to what to look for," said Byron Young, chief of the Fin Fish and Crustacean unit at the New York Department of Conservation.
One of the first factors researchers looked into was the possibility that malathion spraying " carried out over a month ago to ward off virus-carrying mosquitoes " may have seeped into the waters and poisoned the lobsters.
"Lobsters are sensitive to so many things," said Robert Bayer, director of the Lobster Institute at the University of Maine. "Anything that will kill an insect will kill a lobster."
Butwhen Bayer tested samples taken from waters hosting the dead lobsters, he found no traces of the pesticide. "We've pretty much ruled that possibility out," he said.
Lobsters are also vulnerable to viruses and bacteria and, Bayer explained, the insectlike creatures can catch a bug in many different ways. Lobsters are known to attack and eat each other if held too long in a trap and often a lobster's shell is broken during these clashes. Infectious microorganisms can then enter the lobster's system through these cracks.
Bacteria and viruses may also infect a lobster through its gills, which are located under its body shell. Occasionally a lobster can catch a bug through feeding, although its stomach acids are toxic enough to kill most pathogens.
Bayer examined blood taken from the sick Long Island lobsters to look for common infections such as Gaffkemia, a bacteria that has turned up in lobsters since the 1960s. He also looked for signs of Ciliated Protozoans, a pathogen that began afflicting New York lobsters in 1990. Tests for both pathogens turned up negative.
Meanwhile, Richard Robohm, chief of biotechnology at the National Marine Fisheries Service lab in Milford, CT, has scoured Long Island lobster specimens for other bacteria.
"We isolated two kinds of bacteria, but when we injected them into healthy lobsters, they proved harmless," he said with a sigh. "At this point it seems it's not a bacterial infection."
The only other possibilities that remain are either an undetected virus infected the animals or some unknown pollutant in the sediment or water has weakened and killed them.
In past seasons, low oxygen levels in the Long Island Sound have killed off smaller numbers of lobsters. This occurs when massive algae blooms die off and decompose in a process that strips oxygen from the water. Robohm suspects a similar process could be releasing toxic compounds like hydrogen sulfide and ammonia in the water.
He explained pollutants lead to higher levels of organic material at the ocean bottom. Bacteria feeding on that material 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.
"A fish can swim away," he said. "But the problem is lobsters can't get out of the environment fast enough."
Although the numbers of dead trapped lobsters have seemed to taper off in the past two weeks, Young still hopes to get to the bottom of the die-off. At risk is Long Island Sound's annual fall run, which accounts for nearly half the annual income of New York's estimated 900 lobstermen. Such plagues have proven costly in the past. In 1998, a bacterial disease killed off an estimated $2 million worth of lobsters in Maine.
"If we had a clue about what was going on, maybe we could do something about it," he said.
Lobstering is in a lull right now as the creatures go through a monthlong molting process. The next run is expected to start in November and Carbone is nervous his traps may turn up empty.
"We're hoping November is better, but there's no telling," he said. "I've been in this business 15 years and I still haven't figured it out. All I know is it's not worth going out and risking my life, my crew members' lives and my boat for no money."