The Secret Life of Lobsters

by Trevor Corson

  On that day Down East aboard the Vomit Comet, when Jack Merrill had joined the scientists in the waters off Mount Desert Island, the divers had found not a single baby on the bottom. But while they were diving, Lew had been towing his superlobster net along the surface. To his surprise, Lew had hauled in a thick run of swimming superlobsters.

  The ecologists concluded that those superlobsters had been on a sort of suicide mission. The cobble below was a maze of perfect hiding places, yet the superlobsters weren’t landing. Almost certainly they had ended up dying at sea. It was possible that the water below the surface had been too cold for them to settle. And if cold water could leave perfect nurseries in eastern Maine barren, maybe warm water was responsible for the densely populated nurseries in western Maine.

  It seemed like a reasonable hypothesis. Alternative explanations for the sudden rise in catches in western Maine weren’t convincing. In the cod fishery, catches had increased as a result of new technology—nineteenth-century cod fishermen had dropped baited hooks from dories, but by the 1950s, ships the size of factories were consuming entire schools of cod with giant trawl nets and freezing the fish at sea. No similar technological revolution had occurred in the lobster fishery. Except for the switch from wood to wire, the lobster trap had changed little in a hundred years. Even quadrupling the number of traps in the 1970s and 1980s hadn’t resulted in the capture of more lobsters. Instead of blaming the increase in catches in the 1990s on better trapping techniques, the ecologists were forced to entertain the mystifying possibility that the lobster population had simply grown in size—the exact opposite of what government scientists had warned would happen.

  Nor was this increase likely to have been caused by the recent decimation of the codfish, the lobster’s most deadly predator. In coastal waters near shore, the destruction of cod stocks had occurred much earlier in the twentieth century. This time something else was going on.

  Lastly, the government’s partial increase in the minimum size was also insufficient to explain the increase. Only a few years had passed, and it took a lobster about seven years to grow to harvestable size.

  Perhaps the lobstermen’s own conservation techniques—V-notching and the maximum-size law—had been effective in ensuring a surplus of eggs all along. Even if they had, however, dumping more seed on a field—as Bob liked to point out—didn’t necessarily increase the yield of crops. Bob, Rick, and Lew had to conclude that the catches were on the rise because the neck of the demographic bottle had somehow widened. More little lobsters were getting through, perhaps because of recent changes in water temperature.

  Once again, Bob was reminded that populations of organisms were always in flux. By 1994 he was eager to return to Mount Desert Island to take another look. If the bottleneck was widening, perhaps this time Bob would actually find some baby lobsters in the eastern half of the state. And at the very least, if he and Rick could map the pattern of baby, juvenile, and adult lobster abundance along the entire coast as catches rose, they might be able to identify more accurately the process at work.

  Meanwhile, another scientist had found even more baby lobsters in the western half of the state, and she’d done so without even trying.

  After completing her Ph.D. on the mating behavior of lobsters in Jelle Atema’s lab at the Marine Biological Laboratory in Woods Hole, Diane Cowan had become a professor of marine science at Bates College in Lewiston, Maine. Diane liked to escape to the coast from landlocked Lewiston whenever she could. One day she’d been searching for a cove from which to launch her sea kayak when she’d come across a couple of boys playing among the rocks at low tide.

  “Whatcha got there?” Diane had asked, peering into the mud.

  “Lobsters.”

  “Huh?”

  “Baby lobsters.”

  Decades earlier, scientists had noted that young lobsters were briefly exposed on rocky beaches during astronomical low tides, when the alignment of the moon with the sun peeled the ocean away an extra few feet. That knowledge had since been neglected because the lobsters weren’t easy to see—they hid in the wet crevices between stones. But the boys Diane met that day had been keen observers, and they knew what they were looking at. One of them was the son of a lobsterman.

  At first the discovery gave Diane something to show her class on field trips. She would unveil the lobster babies under the stones, give a lecture on habitat, then drive her students down the road to Cook’s Lobster House and order up a round of boiled adults. Over dinner she’d teach her students a lesson in lobster anatomy. For her own dining pleasure Diane would always ask the waiter for a male—more claw meat.

  But Diane soon realized that the cove full of babies afforded a rare research opportunity. She’d read Rick Wahle’s report on cobble nursery habitats. The baby lobsters she had found were in an inlet called Lowell’s Cove, near the tip of Orrs Island, a talon of land jutting ten miles into Casco Bay. It was a few peninsulas to the west of where Rick had conducted his study, but from the look of Lowell’s Cove—shallow water, lots of cobblestones, exposed to the sea—Diane thought it must be a lobster nursery. Just as Rick had, Diane could set a square quadrat on the bottom and take a census of the baby lobsters hiding among the rocks. The difference was that Diane could do it all without going underwater.

  Diane had earned her scuba certification at the age of sixteen and was no stranger to diving. But a pair of rubber boots made for cheaper and quicker data collection than boats, tanks of air, dry suits, and underwater vacuum cleaners.

  In practice, Diane’s data-collection scheme sometimes turned out to be more challenging than she had envisioned. That was the case one October afternoon on an excursion to Lowell’s Cove, typical but for the fact that Diane was running late. By the time she arrived the sun had set, a bitter wind was whipping up a chop across the water, and the miner’s headlamp strapped to her cap projected only a narrow beam of light through the gloom. With a heavy basket of equipment strapped to her back, she picked her way through seaweed-covered rocks to the water’s edge.

  Twenty minutes later Diane was squatting in the mud, surrounded by cottage cheese containers holding the tiny lobsters she’d collected. In her right hand she held an adapted medical syringe. On the tip of her left thumb was a magnetic chip one millimeter long, engraved with a microscopic bar code. The trick was to get the chip inside the end of the hollow needle without the wind blowing it away. Once she’d loaded the chip, the next task was to implant it inside the leg of an inch-long lobster. Diane aimed her miner’s light into the containers at her feet.

  “C’mere, lobbie,” she sang, plucking a baby lobster from its plastic dish and nearly going cross-eyed with the effort of focusing on its front walking leg—the diameter of a toothpick. Diane had captured fifteen babies by flipping over stones, using the same technique as the boys she’d met on the beach. To minimize disturbance to the lobsters, she planned to return each one to the rock where she’d found it. But the tide had already turned. In a few minutes those stones would be back underwater for another month.

  As much as the movement of the tide appears to be a matter of the sea rushing in and out like a frantic commuter, the ocean is, in fact, simply hanging out in the pull of the moon’s leisurely, 27.3-day orbit. It is the earth’s relentless spinning that accounts for the schedule of the tides. Water near the moon is pulled toward it and water on the far side of the earth falls away, causing a symmetrical pair of bulges in sea level and a corresponding slimming of the sea on the sides. Through this gravitational field the earth churns, dragging its continents with it.

  The sun, although very far away, pulls on the ocean as well. When the moon is either at its closest point to the sun or farthest from it—a new moon or a full moon, respectively—the combined gravitational force tugs the bulge of the ocean a little farther from the earth’s core, drawing extra water away from the slimming sea on the sides.

  For Diane that meant some lifestyle adjustments. Astronomical low tides in Lowell’s Cov
e, Maine, occurred for several days at a time, fourteen times a year, when the sun and moon were located in one of four possible combinations over the longitudes of Cairo, Egypt, or Anchorage, Alaska, or both. Diane usually ended up crouching in the seaweed at dawn or dusk, doing half her work by flashlight. Rain, sleet, or snow, breeze or gale, the tides wouldn’t wait.

  Bates College indulged Diane’s peculiar form of research, even if she did occasionally show up for class wet and tired after rising at 4:00 A.M. to dig in the mud. A redesign of the curriculum, however, cut the course Diane taught, so she was forced to look for other work. She tried other teaching gigs, but none allowed her to visit Lowell’s Cove on every astronomical low tide. So after spending seven years earning a Ph.D., Diane walked into Cook’s Lobster House and asked for a job as a waitress. The waiter who’d humored her requests for male lobsters in the past recognized her, and she was hired. The first thing she did was hand the manager a list of the dates and times she wouldn’t be able to work during the next twelve months, copied from her tide calendar.

  Trying not to rush, Diane rearranged her grip on the tiny lobster she was holding.

  “Hold still, sweetie,” she whispered. She inserted the hypodermic needle between the pincers at the end of the lobster’s leg and pushed until the chip was lodged in the muscle of the animal’s forearm. The baby hardly flinched.

  The magnetic chip would serve as a tag in case she recaptured the lobster. Implanting it in the muscle tissue was the only way to be sure the tag wouldn’t be lost when the baby shed its shell. Whenever she came to Lowell’s Cove, Diane brought along her magneto-field detector, a blue box with switches that beeped when it located a lobster carrying a chip. With a pair of scissors Diane would snip off the leg with the chip—the limb would regenerate—and implant a new chip in another leg. Under a microscope, the bar code would reveal when and where Diane had first captured the animal. The tagging data would help Diane determine the rate at which baby lobsters grew and how long they remained in the nursery.

  “You’re a cute one,” Diane said, giving the tagged baby a pat before returning the lobster to its plastic dish. “I hope you show up on my dinner plate someday.”

  “Bottom Dollar, you on there, Jack?”

  Jack Merrill slowed the hydraulic hauler aboard his lobster boat and frowned. He recognized the voice, but couldn’t place it.

  “Yeah,” Jack said into his mike, “this is the Bottom Dollar, go ahead.”

  “Jack, it’s Bob Steneck. How are you?”

  “Hey, Bob! You in the neighborhood?”

  By the strength of Bob’s radio signal, Jack guessed the scientist was aboard a boat somewhere within fifteen miles of where Jack was fishing off Little Cranberry Island.

  “Yup, we’re doing some diving today around your island.”

  “Great. Stop by when you’re done, we’ll grab a beer and some dinner.”

  “Sounds excellent. See you then.”

  Ever since Bob had made his first presentation to the Maine Lobstermen’s Association, he’d been impressed by Jack’s friendly demeanor. Now, whenever Bob was working off Mount Desert, he made a point of calling Jack on the radio. Those calls served another purpose. Other fishermen listened in, so the conversation became Bob’s permission slip to do research in their territory. By now he was wise enough not to steer his boat into a cove dense with lobster buoys without checking with the local fishermen first.

  A few weeks earlier Bob had perused a pile of coastal charts with his new intern, a young fellow named Carl Wilson. Carl was an earnest student with a warm smile and a six-foot-four frame. Quick with a joke, he’d grown up in Maine and had spent his summers on Isle au Haut, an island lobstering community twenty miles west of Mount Desert Island. He was familiar with fishermen and eager to get himself wet, whether it was piloting a research skiff through a stiff chop or sucking lobsters off the seafloor with an underwater vacuum. Bob couldn’t have found a better ally for the work that lay ahead.

  Bob and Carl had studied the charts for coves that might have the same characteristics as Rick’s most productive nursery, the western side of Damariscove Island. This ideal site protruded off the coast like a catcher’s mitt, facing straight into the southwesterly summer breeze that delivered superlobsters. Scouring a chart of the waters off Mount Desert, Bob had noticed that the south beach of Little Cranberry was connected by a half-submerged bar to Baker Island in the southeast, creating a mile-long semicircle—it too looked like a sort of catcher’s mitt, facing into the summer winds. Bob recalled the hot August day when he’d sat on that same beach with his wife and parents. The beach had been a vast sweep of cobblestones. Maybe on the Argo cruise, he and Rick had dived in the wrong places. Bob put Little Cranberry’s cobblestone cove on the list.

  The more they dove along the coast, the more locations Bob and Carl added to their survey. Two hundred miles to the south, Massachusetts biologists began taking suction censuses, using the techniques that Rick had pioneered. Along with Rick’s original nurseries in the western part of the Maine coast, plus the ones he’d added in Rhode Island in the early 1990s, ecologists were soon gathering annual data at more than sixty locations along the coast of New England. Canadian scientists even added a few sites in New Brunswick. The lobster-settlement index the ecologists had envisioned was becoming a reality.

  In addition, assistance came from everyday residents of coastal communities. In 1996 Diane Cowan had founded a nonprofit organization called the Lobster Conservancy. She’d quit her waitressing gig at Cook’s Lobster House and was now training volunteers to count baby lobsters at low tide. Collaborating with Bob, Rick, and Carl, Diane set up coastal sites to match some of their underwater dive locations and added sites of her own. Helping to coordinate much of this work was an organization called the Island Institute, based in Rockland, Maine. Of the three hundred Maine islands that had been inhabited year-round in the glory days of the cod fishery, most had been abandoned. For the sake of Maine’s coastal villages, including the fourteen island communities that remained, scientists, fishermen, and local residents would have to cooperate to make the lobster fishery last.

  The level of data collection was unprecedented. By observing patterns in nature and mapping them, Rick, Lew, Bob, and their colleagues were learning to track the health of the lobster population, and soon they might even be able to forecast future trends. They still didn’t know exactly why the demographic bottleneck had widened, causing an increase in catches, but they were sanguine that answers could be found.

  Before long, however, the ecologists were wrapping their minds around a more vexing puzzle. Catches had continued to rise, but beginning in 1995 Lew noticed a dramatic drop in the abundance of tiny superlobsters that were caught swimming off the coast. At the same time, Rick saw the number of new babies in the nurseries plummet. Off Little Cranberry Island, Bob had finally found a few baby lobsters, but their numbers weren’t anywhere near those in the west.

  As they patrolled the stony seafloor along the coast, the ecologists felt like hall monitors in a popular school that had suddenly lost its pupils. They kept their observations to themselves until they could gather more data. But if the slump lasted, the consequences for the lobstermen of Maine could be devastating. Had the government scientists been right all along?

  PART FIVE

  Sensing

  13

  See No Evil

  The eye of the lobster is of such novel and ingenious design that it inspires religious faith and scientific admiration alike. The eyes of most creatures on the planet use lenses to refract light. A lens forces rays of light to pass, at an angle, through a medium that slows them down, thus altering their trajectory. But the lobster’s eye, in a design shared with only shrimps and prawns, focuses light by an entirely different principle—not refraction, but reflection. There are no lenses under a lobster’s cornea but instead a grid of mirrored boxes. Each box is a long square duct, open at the top and tapering to a point at a package of retina
l cells. The four interior walls of the duct are coated with a crystalline lining, and as rays of light enter the open end of the box, they glance off one of the sloping walls at a shallow angle. Like speeding cars grazing a highway guardrail on a gentle curve, the rays of light change direction just enough for them to converge onto the retinal cells at the far end. Each of the lobster’s two eyes consists of some thirteen thousand of these tapered boxes.

  Religious creationists cite the unique and ingenious construction of the lobster eye as evidence of an intelligent Designer; the surface of the square openings is as geometrically exact as graph paper, and the grazing angles inside each box must be mathematically perfect for the retinal cells to receive light. Scientists agree that this construction is ingenious, and they are using it as the blueprint for a new X-ray-vision space telescope called Lobster-ISS, so named because it will be mounted on the International Space Station. The mirrors that usually focus light in telescopes are useless for focusing X-rays because mirrors simply absorb short wavelengths—with one exception. At a very shallow grazing angle, a mirror can alter the trajectory of an X-ray signal just enough to redirect it without absorbing it. Employing the design of a lobster’s eye, the Lobster-ISS will use millions of tiny tapered mirror boxes, fifty to a square millimeter, to collect X-ray images of great swaths of the sky.