In Win Watson's zoology lab there lurks a creature named Pinchy II. The six-inch-long baby lobster lives by herself in an aquarium where she peers out from beneath a rock. Whenever someone approaches her tank, she marches up to the glass and raises her open claws in a threatening display of miniature pinching power. This behavior is no random occurrence. No matter how many times a visitor returns to the tank, the baby lobster pops out of the shadows, showing off her bulging claws and forearms just above a sign that reads: Beware Attack Lobster.
The lobsters we think we know -- denizens of dark, dank grocery-store tanks, piled on top of each other and crammed into corners -- actually behave quite differently in other settings. In the lab, they have what it takes to walk a treadmill or negotiate a simple maze. In the wild, they joust like little knights, bury their food, and mate with amazing tenderness and abandon. Yet there is still much to learn. When it comes to how the animal behaves in its environment, says Watson, a UNH professor of zoology, "we really know squat."
The life of the lobster has been shrouded in mystery for years -- and for years, the lobster fishermen liked it that way. Dan Millar '78, who has been lobstering out of a craggy peninsula in Casco Bay, Maine, for the past 24 years, understands the urge to be secretive. "I'll tell you how many traps I have if you tell me how old you are," he once told a curious tourist. She got the point. Now that Maine lobstermen -- and women -- are limited to 800 traps apiece, that number is public knowledge, but other information remains well guarded. Millar knows lobstermen who would fire an employee who divulged the day's catch.
A zoologist by training, Millar has recently divided his time between lobstering and a job monitoring Maine's salmon-farming industry. He knows how frustrating it can be for scientists when fishermen refuse to share information that could be used to preserve the fishery. But among lobstermen, he explains, "there's always the feeling that scientists are out to prove there's a problem and cut me back."
The lobstermen have a point. Over the past 100 years, scientific models have repeatedly predicted the collapse of the lobster population in New England. Lobster landings remained steady for most of that time, and in the past 20 years, tripled from 20 to 60 million pounds a year in Maine alone. Reassuring? Perhaps. Then again, fish like cod and haddock also saw an increase in catch shortly before those populations collapsed. Moreover, the lobster populations off Long Island, Rhode Island and Connecticut have already gone into a slump. As much as they may hate the word "sustainable," many lobstermen are worried. Some have even begun collecting data for scientists they trust.
Win Watson is one of those scientists. "I tell my students this research is like working on a big jigsaw puzzle," he says. "All we can be expected to do is add a couple of pieces. And it would be really cool if we can find edge pieces or a corner piece and set some limits." As a zoologist with a specialization in neurobiology, he tends to ask basic questions: Can a lobster find its way home? Where and why does it migrate? Can lobsters communicate with each other? How do they behave around lobster traps? The answers to those questions could shed some light on the behavior of Pinchy and her kind, while helping scientists and lobstermen preserve a very valuable -- and delectable -- resource that is critical to the livelihood of thousands of New England families and a whole way of life in coastal communities.
The Lobster Ponderosa
Lobstermen call them "bugs of the ocean," and as arthropods -- jointed creatures with exoskeletons -- lobsters are related to insects. Clumsy on land and sluggish in tanks, they don't seem particularly capable. But venture down 20 feet below the surface of the ocean with zoology graduate student Darren Scopel, and the tables are turned. Encumbered by 100 pounds of diving equipment, Scopel moves slowly. He can hear only the rhythmic rush of exhaled bubbles, can see little beyond 10 feet away, and often has to use a compass to figure out which way is which.
The lobsters, on the other hand, dance like marionettes on strings, waltzing about on their many tiptoes. Acutely aware of their environment, a group of them sense Scopel's presence and turn toward him. One lobster marches up to Scopel's video camera, and lifting its heavy claws, raps twice on the camera housing.
Watson, who also studies the lowly sea slug, believes we underestimate many species, and he has been first to demonstrate some of the lobster's abilities. He is known for being a prankster, and some of the experiments and gadgets he's rigged up with the help of duct tape and Superglue almost sound like practical jokes. He devised a mini-treadmill to study lobster locomotion, for example, and a lobster heart monitor. It's not a lobster stress test, but a way of identifying some of the things, like a change in water temperature or salinity, that are so exciting or alarming to a lobster that its heart stops beating momentarily. His latest improbable-sounding experiment has two of his students, master's candidate Heidi Pye and Ben Winslow '04, spending hours every month holding lobsters at a lobster pound to try to figure out why roughly one out of every 10 lobsters will buzz when handled. Pye has also used the heart monitor to discover that a lobster's heart will skip a beat when it hears the sound of a tankmate buzzing.
Watson's lab work on sensitivity to salinity, combined with field work in New Hampshire's Great Bay, has helped fit one piece into the lobster-population puzzle, demonstrating for the first time that lobsters will migrate according to gradients in salinity. Watson has also collaborated with Diane Cowan, senior scientist at Maine's Lobster Conservancy, in a major study of lobster migration patterns. With the help of several lobstermen, the researchers are tracking lobsters with ultrasonic devices. So far the research indicates that there may be three types of lobsters: homebodies who spend months at a time in one harbor, regional travelers who stay within a radius of 20 miles, and long-distance lobsters who in winter may travel 100 miles or more to warmer waters off the continental shelf, returning home for breeding in the summer.
Watson has constructed a sort of lobster corral, dubbed the Lobster Ponderosa, to study another type of lobster movement: their ability to repeatedly return to one shelter. Roughly half the size of a football field, this underwater enclosure is located just offshore in New Castle, N.H. By tracking their movements, Watson has been the first to verify lobsters' homing behavior. He and Scopel have also developed a maze to study whether lobsters can recognize, and remember, left from right.
Down in the Ponderosa, lobsters have given further evidence of their abilities. After being handled by a diver, a lobster typically takes a mile-long hike, and in the corral, they head southeast toward deeper, safer waters. But how do the lobsters know which way is southeast? Are they, like spiny lobsters, able to sense the earth's magnetic field? Or are they, like desert ants, able to remember routes previously traversed?
When he is attaching sonar tags, Scopel often takes time to observe the lobsters. When two lobsters approach each other, they raise up their claws and start sparring. The larger lobster prevails, and the loser suddenly vanishes in a cloud of underwater dust, swimming in the only way it can: plunging backward away from danger with a powerful thrust of its tail. In the future, the smaller lobster will deferentially give the winner a wide berth. Between two lobsters of the same size, Scopel says, the one with the most "attitude" wins.
Lobstermen come in two varieties. The vast majority of New England lobstermen stay within 40 miles of land and return to port at the end of the day. In Maine alone, there are roughly 5,000 of these inshore lobstermen at work. The offshore lobsterman is a much rarer breed that can be found south of Maine, fishing the deep-sea canyons at the edge of the continental shelf, more than 100 miles out and up to 1,200 feet down. This is lobstering writ large, with bigger boats, bigger lobsters, bigger profits -- and bigger risks at sea. In wintertime, for example, ice on the rigging can capsize a boat.
Several offshore lobstermen have helped UNH scientists study the size at which lobsters in different geographical areas reach sexual maturity -- a critical piece of the puzzle for determining when a lobster should be considered legal.
Whether inshore or offshore, the lobstering routine is much the same. The captain retrieves each lobster from the trap and measures the carapace, or top half of its "armor," with a metal gauge to see if it's of legal size (currently 3.5 inches). Maine lobstermen must throw back anything with a carapace longer than five inches, but for offshore lobstermen, there is no upper size limit. The largest lobster ever caught weighed more than 45 pounds.
Virtually every lobster that comes up takes a final stand in the lobsterman's hand, flipping its strong tail in an attempt to backpedal into the ocean, or drawing up its chest and claws like Popeye-on-spinach in a threatening posture called the Meral spread. It's not an idle threat. On a large lobster, the crusher claw is strong enough to break a man's finger, and even a small lobster can draw blood with its pincer claw. (To be released, some lobstermen squeeze the other claw.)
In many ways, lobstermen behave like dairy farmers, feeding the lobster population in their traps and managing the "herd." In addition to throwing back undersized lobsters, they release every egg-bearing female after notching her tail to identify her as a proven breeder. Lobsters remain the only profitable wild fishery in New England perhaps in part because of these practices. Another factor is the lobster trap itself. "The lobster fishery is in pretty good shape in part because the traps are so bad," says Watson. "It's almost as if we're working with the lobsters."
One Life to Live
Although Watson has had a number of firsts in lobster research he is best known, nationally and internationally, for creating a crustacean version of reality TV. With the help of UNH ocean-engineering students, Watson, UNH zoologist Hunt Howell, and Steve Jury '88, '99G devised a way to monitor a baited lobster trap for 24 to 48 hours at a time with a with time-lapse video camera set-up dubbed Lobster Television, or LTV. The resulting videos resemble old-fashioned silent movies, with lobsters lurching about the trap like Keystone Crustaceans. (To watch some of the videos, visit <http://www.lobsters.unh.edu>.)
The lobster trap in use today, whether made with vinyl-coated wire or wood slats, was designed in the 1830s. There are two one-way entrances into the "kitchen," where a bag of salted herring hangs. Lobsters, believed to be nocturnal, were expected to eat and then move into a separate compartment called the "parlor," with exits designed to allow sublegal-sized lobsters to escape. For years, scientists based their lobster-population estimates on surveys of lobsters caught in traps even though there was no documentation of the correlation. The surprising evidence provided by LTV has dramatically changed how fishery managers look at lobster-trap surveys.
In their study, Watson and Howell found that only about 10 percent of the lobsters around the trap entered, and a mere 6 percent of the lobsters who entered were caught, largely because they had the bad luck to be in the trap when it was hauled up. Instead of a Crustacean Hotel where the lobsters would "check in and never check out," the lobster trap works more like a 24-hour roadhouse where the patrons are generally free to leave -- usually through the supposedly one-way entrance. The brawling customers are constantly chasing each other out or scaring others off at the doorway. As usual, the lobster with the biggest claws wins. To Watson, they are "ornery, solitary animals who are angry all the time."
Diane Cowan sees a very different side of lobsters. The mating behavior she observed in two large tanks looked a lot more like "One Life to Live" than something out of "The Wild Wild West."
A lobster begins its potentially long life by going through seven to eight years of juvenile stages, molting once or more a year and expanding in size by roughly 12 percent every time. Before reaching adulthood, Cowan discovered, lobsters pass through a flirtatious adolescent period that stops short of mating, perhaps in recognition of the commitment it takes to carry thousands of eggs around on one's swimmerets for a year. Adults continue to grow slowly and molt occasionally, scientists believe, for up to 100 years.
Among the lobsters Cowan studied was a male she discreetly named "M." When a female -- let's call her "Q" -- has a tryst with M, she announces her arrival at the entrance to his den with a squirt of urine laced with pheromone, a chemical attractant. Once inside, she undresses in a most dramatic fashion, wriggling entirely out of her shell, and then lies limp as a dishrag for half an hour, pumping water into her new shell. M, resisting the urge to dine on lobster, stands quietly by. Then he gently flips her over and cradles her with his walking legs while they mate in a matter of seconds. Afterwards, they dine on Q's cast-off shell, a delicacy among lobsters, and Q safely rests in the shelter for a few days until her shell has hardened enough to withstand the lobster-eat-lobster world outside.
Not long after Q and M's rendezvous ends, another female lobster will appear, ready to boogie. In fact, the females appeared to time their molting to occur in succession, each visiting M in a pattern Cowan termed "serial monogamy." "People have described lobsters as solitary," she says, "but I consider them highly social. They know where their neighbors live and know what molt stage they're in. It's not just whether an animal has a backbone or not that makes it simple or complex."
Cowan and Watson are now seeking a grant to take the mating research a step further out into the experimental environment where Watson studies homing behavior. His tracking studies suggest that males may set up mating territories, possibly defending multiple females in multiple shelters. By using identifying sonar tags with transmitters, Watson believes, they could really keep tabs on lobsters in love.
Boom or bust?
When he gets home from a day at sea, Dan Millar often lies down on the floor to get the kinks out of his back. "I already know what rigor mortis is," he says with a laugh, "and I don't think I'm going to enjoy it." Millar's boat, F/V Rewben, is named after his sons, Andrew and Benjamin, who he hopes will not follow in their father's footsteps. "This business is too hard," he says. "Your average work week is 60 hours, easy." Which is not to say that Millar is bitter. For one thing, the money hasn't been bad. Carl Wilson '95, chief lobster biologist for the state of Maine, estimates that the typical Maine lobster boat grosses $200,000 to $300,000 a year and supports two families. Like most lobstermen, however, Millar seems to be in it less for the money than the independence -- which allows him to attend many of his sons' ball games.
In spite of the record lobster landings of recent years, Millar worries that a downturn is inevitable. He has already seen a few cases of the bacterial shell disease that is disfiguring, but not killing, lobsters in southern New England waters (under study by UNH assistant professor of microbiology Elise Sullivan). Wilson, Cowan and Watson share his concern, pointing out that 80 percent of the lobsters caught in Maine are just above the legal limit, which means, according to research done by Watson and others, that only 50 percent of those lobsters have reached the age of sexual maturity.
Is the lobster population booming or at risk of sudden collapse? Are lobsters being over fished or carefully tended? Are they sensitive neighbors or angry hermits? The answer thus far may be something like "all of the above." Scientists, regulators and fishermen are a bit like the proverbial blind men groping their way around an underwater elephant. The contradictions they find may just be different views of a complex creature fished by complex people trying to maintain a fishery in a complex world. In the meantime, Watson and his collaborators will keep using technology, creativity -- and duct tape -- to piece together more of the lobster puzzle. ~
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