Stalking the American Lobster

Government scientists say that lobsters are being dangerously overfished. Lobstermen insist that stocks are plentiful. It's a familiar kind of standoff—except that now a new breed of ecologist has taken to the waters, using scuba gear, underwater robots, and even nuclear submarines, in order to figure out what's going on. It turns out that the lore and lessons of the lobsterman are worth paying attention to

But Merrill and his colleagues in the MLA don't think Idoine's recommendations are necessary. They believe that the scientific models fail to factor in the margin of safety that lobstermen have built into their fishery for decades: a pool of large reproductive lobsters, protected not only by Maine's maximum-size restriction but also by a curious practice known as V-notching.

A cornerstone of Maine's conservation ethic, V-notching dates to 1917 and has been largely self-enforced by Maine lobstermen since the 1950s. V-notching is all about making babies. The sex life of lobsters does not get wide public attention, but it has attracted the interest of a small number of researchers. One of these is a biologist named Diane Cowan, a onetime professor at Bates College who is now the president of The Lobster Conservancy, a nonprofit research center dedicated to involving Maine coastal communities in lobster science.

Cowan once spent several months observing the behavior of a male lobster she had named M, which lived with one other male and five females in a tank at the Marine Biological Laboratory in Woods Hole, where Cowan later worked as a graduate student. Every night M would emerge from his shelter, boot all the other lobsters out of their shelters, and then return home. The females got the message: M was dominant. The females visited both of the males at their shelters, but M got far more lady callers than the other male. The visits were decorous at first: an interested female would insert her claws into the entrance of M's shelter and wiggle her chemoreceptor antennules to smell him. Then she'd urinate at him from the front of her head, releasing pheromones. In appreciation M would spread her urine throughout his apartment, by standing on tiptoe and fanning the water with his swimmerets—little fins along the bottom of the lobster's tail, arranged in five pairs.

Having ascertained mutual interest, the two abandoned all caution. M's primary concern seemed to be how soon the female would undress for him, and he would show his impatience by boxing the surfaces of her claws with the tips of his. Females can mate only after they shed their shells; Cowan thinks that M's boxing was a way of testing how hollow his lover's shell was in preparation for molting.

"One day I walked into the lab, and I thought there were three lobsters in M's shelter," Cowan says. It turned out to be not a ménage à trois but, rather, evidence of a conventional coupling. It was M, a female, and her molted shell. When a female that wants to mate is ready to molt, she lets the male know by placing her claws on top of his head, in a behavior scientists have termed "knighting." This apparently indicates to the male that he must protect her while she sheds her shell; scientists think the female may also release a sex pheromone that discourages the male from simply eating her, as he might under other circumstances. Once the female is undressed, the male gingerly lifts her soft body, flips her on her back, inserts a pair of rigid swimmerets into a pair of receptacles at the base of her abdomen, and passes his sperm into her. It's like the missionary position, but with double the genitalia.

Once the female's new shell had hardened, after a week or so, she moved out and a new female moved in. It turned out that all the females in the tank wanted to mate with M, and Cowan discovered that they were able to time their molts consecutively so that each would get a chance. Cowan describes the phenomenon as serial monogamy, and she has published papers on it; but she has also learned that females don't always follow its rules. "One night another female got in the shelter and took a chunk out of the [resident] female," Cowan says. "Lobsters get PMS—pre-molt syndrome. Before they molt, they have an activity peak and can go a little berserk." When Cowan altered the sex ratio in the tank, things got more confused. "When I had three males and just two females, the females couldn't make up their minds which male to stay with," she says. "They kept switching from male to male instead of pair bonding with just one guy. It was absolute chaos. It was horrible." Cowan altered the ratio further, and the results were even worse: "I tried to have five males and two females in the tank, but the males fought so aggressively that I had to take two of them out. Pretty soon even the remaining males had no legs left. They were walking around on their mouth parts because they were killing each other."

Lobstermen realize that producing offspring is a big commitment for a female lobster—up to twenty months of pregnancy and tens of thousands of eggs. At first the eggs develop inside her body, and she may wait for as long as a year after copulation to extrude them. Then she finds a secluded spot, rolls over onto her back, squirts the eggs onto the underside of her tail, and carries them around for another nine to eleven months. When they finally hatch and become larvae, she releases them into the ocean currents.

Once a female is carrying eggs, she becomes a kind of goddess to lobstermen. Most Maine lobstermen who find an "egger" in a trap will cut a quarter-inch V-shaped notch in her tail flipper (if she isn't notched already) before setting her free, and from then on it's illegal to sell her, whether she's carrying eggs or not. When she molts, the notch will become less distinct, but conscientious fishermen like Bruce Fernald and Jack Merrill always cut a new notch. "She's a proven breeder," Fernald says, "so we protect her." V-notched females and the oversized males that are protected by Maine's maximum-size law form a pool of reproductive lobsters called brood-stock. Lobstermen are convinced that brood-stock lobsters more than compensate for any deficiencies in egg production by smaller lobsters.

They're not necessarily wrong. A female lobster that has mated can extrude about 10,000 eggs if she has recently reached sexual maturity but ten times that if she is bigger. An older female lobster is also savvier: she can retain a male's sperm inside her body, perfectly preserved, for up to several years after copulation. She can use that sperm at will to produce a second batch of eggs. One Canadian researcher estimates that to achieve the egg production of a single five-pound female—a common size for a veteran V-notched lobster—more than ten smaller females would have to be protected. The lobstermen have a different way of saying the same thing: if V-notching were replaced by an increase in the minimum size, the increase would have to be so great that the only lobsters fishermen could legally catch would be too big to eat.

When Robert Steneck started scuba diving off the coast of Maine, in 1974, he was studying echinoderms and gastropod mollusks, but he kept getting distracted by lobsters. He'd been a researcher for the Smithsonian in the Caribbean, and he remains an internationally recognized expert on coralline algae, but in Maine he found a new calling. "There were all these lobsters and this huge industry that mattered to people," Steneck recalls. "I looked in the literature and realized that we knew almost nothing about lobsters in their natural habitats. I said to myself, 'Why the hell am I studying limpets?'" And there was a bonus in the study of lobsters: "At the end of the day you can have them for dinner."

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Trevor Corson is author of the worldwide pop-science bestseller The Secret Life of Lobsters and the highly acclaimed The Story of Sushi. His website is TrevorCorson.com. More

Trevor Corson is the author of the worldwide pop-science bestseller The Secret Life of Lobsters and the highly acclaimed The Story of Sushi: An Unlikely Saga of Raw Fish and Rice.

He spent two years studying philosophy in China, another three years in Japan living in temples and studying Buddhism, and two more years working as a commercial lobsterman off the Maine coast.

He has been an award-winning magazine editor and has written about food, religion, foreign affairs, and a wide variety of other topics for the New York Times, the Wall Street Journal, the Los Angeles Times, the Boston Globe, and the Atlantic, where The Secret Life of Lobsters began as an essay that was included in The Best American Science Writing.

As one of the leading authorities on sushi in the West, Trevor serves as the only "Sushi Concierge" in the United States, hosting dinner classes in New York and Washington D.C. and educational dining events for organizations, corporations, and private groups. He is also a consultant to sushi restaurants, working to bring a more authentic Japanese experience to Western diners.

Trevor is a frequent public speaker and his work has been featured on CBS Sunday Morning, ABC World News with Charles Gibson, NPR's All Things Considered and Talk of the Nation, as well as numerous local television and radio programs; he also appears as a judge on the Food Network's hit TV show Iron Chef America. His website is TrevorCorson.com.
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