Digital Extra

Tom Angell, a state Division of Fish and Wildlife biologist specializing in lobster studies, says that petroleum products like kerosene and oil lure lobsters. Old-time lobstermen used to soak their wooden lobster pots in kerosene, Angell says, and there are stories of old-timers baiting their traps with oil-soaked rags, stuffed in bottles.

While scientists have no way to determine the long-term effects of this spill on the lobster population -- or whether they sought out the leaking oil -- it is clear that this marine creature was most drastically affected by the spill.

Yet even without an oil spill, a lobster's chance of survival is next to nil.

A small female lobster produces between 3,000 and 4,000 eggs; a 5-pounder may produce as many as 100,000 eggs, according to Angell.

In Rhode Island waters, he says, the eggs generally hatch from mid-June into August; the peak hatch occurs at the beginning of July.

Only 1 percent survive the first stage of life as larvae.

"Just about everything preys on a lobster larva," says Angell, "including other lobster larvae."

Storms and even heavy rains can kill lobsters during the larval stage. After shedding its outer shell four times during four weeks as a larva, Homarus americanus settles to the bottom to begin a new, secretive phase of its life. On a cobbly bottom, like the one near last week's oil spill, the young lobster finds a hole it can call home so it can suck food from the water without getting sucked out and eaten itself.

Its predators include many fish, striped bass and tautog among them. At a year old, the lobster's carapace -- the shell covering the head and body, but not the tail -- is less than 3/4 of an inch long; at 2 years old, the carapace is smaller than 2 inches.

As the lobster outgrows one hole, it moves to a larger one. "They're very reclusive," says Angell. Between 3 and 4 years old, Homarus starts to move about. Large enough now to be intimidating to many of its small predators, the juvenile lobster prowls and preys upon worms, shellfish and finfish. Opportunistic, it also eats algae and other plants.

Meanwhile, cod, conger eels and many other predators continue to prey on the young lobster.

Male lobsters grow faster than females.

Generally when it is between 6 and 8 years old, Homarus becomes long enough for a lobsterman to keep legally: its carapace measures 31/4 inches, and the animal weighs about a pound.

By then, a female may have mated once or twice. She keeps the male's sperm in a sac for six to eight months, then releases it onto her eggs as she extrudes them onto her abdomen. During the 9 to 12 months when a female lobster is carrying eggs, state law prohibits keeping the female lobster.

Sharks and wolffish are among the predators that eat adult lobsters, eggs and all.

Some adult lobsters seek rocky crevices for security; others create their own covert by burrowing in the mud. As it gets older, Angell says, the lobster's growth rate slows. "There's no way to age a lobster like a tree or a fish by counting growth rings. It's a guessing game. A 25-pounder may be 60 to 80 years old."

In Rhode Island waters, Homarus rarely makes it beyond the year it achieves legal length. "Between 90 and 95 percent of them are captured," the biologist says. Rhode Island lobstermen land about 6.5 million pounds of lobsters a year; 45 percent from inshore waters, with the majority coming from offshore.

Scientists have no way to tell whether the oil lured thousands of juvenile lobsters to the spill. They have no way to determine whether the spill will affect the lobster population in the long run. But they do know that the odds of a lobster surviving in the wild are low from the start and that, in the end, the oil did kill thousands of young lobsters.