The Secret Life of Lobsters

by Trevor Corson

  Diane’s task was complicated further when her Belgian sheepdog, Bear, insisted on going to sea with her. Though Diane was his fifth owner, he defended her from any threat as though she were his first. Threats, it turned out, were everywhere, especially aboard Diane’s boat. When she spun the steering wheel a certain way, the growling outboard motor on the stern would turn to glare at Bear, and the dog would leap through the tangle of hydrophone wires to bite off another piece of the engine’s rubber gasket.

  Eighty percent of the sonar lobsters Diane released were successfully tracked or recaptured. Diane was startled to learn where they’d been. Many scientists have assumed that the first priority for an egg-bearing lobster is to find temperate water, where her eggs can develop quickly and hatch. But the movements of Diane’s lobsters, and the logs of their temperature recorders, provided little evidence of such a search. The distances the lobsters traveled ranged from a few feet to a hundred miles. About a third of the females remained in the immediate neighborhood to hatch their eggs, about a third roved within a twenty-mile radius to find a hatching location, and about a third set off with their eggs over much longer distances.

  If these movements were typical of egg-bearing lobsters everywhere, Diane guessed, she might have stumbled onto a reproductive strategy directly opposed to the well-known reproductive strategy of the salmon. Salmon return to their exact birthplace to hatch their eggs every generation, which leaves them vulnerable to natural or man-made shifts in the environment. By contrast, female lobsters as a group appeared to be hedging their bets by fanning out. To Diane, hatching eggs in as many places as possible seemed a wise strategy for a species that cast its young into the fickle currents of the ocean.

  In another ocean-modeling session, Lew Incze ran the larval-transport simulation for the Gulf of Maine forward instead of backward. He gave the computer ten combinations of nearshore and offshore hatching locations around the gulf to mimic geographical variations in lobster migration, and he posited early, middle, and late hatching times for a hypothetical spawning season.

  The computer’s calculations showed that most of the larvae followed the gulf’s counterclockwise gyre. As Lew had expected, many were delivered by the Eastern Maine Coastal Current from locations off Nova Scotia, the Bay of Fundy, and Down East Maine over long distances to the nurseries along the western half of the Maine coast. Not surprisingly, other larvae that had hatched near shore, especially in western Maine, were often not exposed to the gulf’s large-scale currents and traveled only short distances, landing in local nurseries.

  But what took Lew’s breath away was the extent to which small changes in location, timing, and temperature at hatching could swing larval trajectories away from the nurseries, regardless of whether water temperature at the nurseries was hospitable. The computer simulations he was running were rudimentary, but the general implications were all too clear.

  Under favorable conditions, any given nursery could receive vast numbers of larvae, many of them coming from a few miles away and others coming from a hundred miles up the coast. But under slightly different conditions, the larvae from distant hatching locations in the north, as well as the larvae that hatched near shore in the southwest, could be diverted by the gulf’s powerful currents into deep and cold water offshore, leaving the coastal nurseries all but bare.

  The American lobster is not unique in casting its young into the currents of the sea. Creatures as various as the codfish and the rock crab do the same thing. The difference is that when a female lobster tosses her hatchlings from her tail, she is, in a sense, aiming for a target. Codfish and rock crabs don’t have nursery grounds, because their larvae aren’t nearly as sophisticated as a superlobster. The larvae of the cod and crab are passive creatures that settle wherever the ocean puts them, which often means into the mouth of the nearest predator. By contrast, the superlobster’s ability to seek out hiding places is the lobster’s secret weapon. By exerting a degree of control over its fate, the superlobster vastly improves its chances of survival.

  But this is also the lobster’s greatest reproductive liability. A single cod or crab mother makes millions of eggs. For a mother lobster, the extra resources required to build her miniature superheroes means she can make only thousands. It is a risky strategy, because the delivery system that lobsters depend on—ocean currents—can fail to carry their limited numbers of offspring to their targets—the nurseries.

  A variety of climatic and oceanographic phenomena can influence the currents from one year to the next, as Lew knew from monitoring the satellite, surface, and undersea data collected by GoMOOS. Shifts in prevailing winds, the orientation of the jet stream, cloud cover, and even the amount of ice melting in the Arctic could all affect how water moved around the Gulf of Maine. Any combination of effects was possible. A given nursery could experience both the retention of local larvae and the delivery of distant larvae. Or it could experience one without the other. Or, in the worst case, it could experience neither.

  Because of climatic and oceanographic conditions inside the gulf, it was conceivable that an entire region of the coast could explode with baby lobsters or slump into vacancy, regardless of fluctuations in the number of female lobsters producing eggs. Lew suspected that a large portion of the larval supply to Maine’s coastal nurseries was locally hatched, but it seemed plausible that currents, temperatures, and other oceanographic factors along the coast had been preventing larvae—from both local and distant sources—from reaching the nurseries of western Maine during the second half of the 1990s.

  Yet powers beyond the Gulf of Maine were at work too. By now Rick Wahle had more than a decade of data on baby lobsters, not just from western Maine but also from Rhode Island. Lew and Rick pored over the annual censuses from the lobster nurseries. The drop in baby lobster abundance from 1995 onward was similar in both locations. It was an astonishing fact, since oceanographic conditions in the Gulf of Maine and Rhode Island Sound are almost completely unrelated.

  Lew concluded that some large-scale shift in a prevailing atmospheric system, in addition to currents specific to the Gulf of Maine, could be driving lobster abundance. There was an obvious candidate, though its influence remained unproven—the North Atlantic Oscillation. An eastern counterpart to El Niño, the oscillation is a titanic seesaw in pressure distributions over the North Atlantic that tips into a subtropical high or a polar low for years or even decades at a time.

  The water that enters the Gulf of Maine tends to be dominated by either southern water from the mid-Atlantic latitudes, which is warmer, or northern water from the Labrador Sea, which is colder. The North Atlantic Oscillation can push the Gulf Stream away from the edge of the continental shelf, which appears to affect which type of water is dominant in the Gulf of Maine. Because the water inside the gulf has its own patterns of circulation, however, the connection is by no means direct. Lew could detect no obvious relationship between the North Atlantic Oscillation and lobster abundance along the coasts of either Maine or Rhode Island. But clearly, something big was going on.

  For the study of lobster ecology in the Gulf of Maine in the years to come, the primary challenge would be to determine the trajectories of actual larvae, from the locations where they hatched through the currents of the sea to the locations where they settled to the bottom—and to do so while monitoring the abundance of lobsters at various stages in the animal’s life cycle: numbers of eggs, larvae, babies, and adults.

  It would be a threefold task. First, the distribution of both nearshore and offshore egg-producing lobsters throughout the gulf would have to be mapped. Diane Cowan’s sonar-tracking project, Carl Wilson’s counting and tagging of eggers during sea sampling, and Bob Steneck’s ROV dives would provide information on where mother lobsters were hatching their eggs and in what numbers.

  Second, analysis of ocean movements by Lew Incze and other oceanographers would provide information on where the larvae were going after they hatched, both on short trajectories near shore and
long trajectories down the coast.

  Third, vacuum sampling in lobster nurseries by Rick Wahle, Bob Steneck, Carl Wilson, and other biologists along the New England coast, as well as tidal sampling by volunteers working through Diane Cowan’s Lobster Conservancy, would provide information on where the larvae were settling on the bottom, and in what numbers.

  By monitoring all three sets of information simultaneously, ecologists might one day be able to identify the causes—and predict the effects—of fluctuations in lobster abundance as they occurred.

  Lobster science had come a long way since 1895. Yet in a sense, science had simply confirmed the conclusions that lobstermen like Warren Fernald, his sons, and Jack Merrill had arrived at themselves. After the lobster crash of the 1920s and 1930s, the lobster industry had recognized the need to protect the supply of eggs. Beyond that, most lobstermen believed that fluctuations in the catch were beyond their ability to control. Even at the beginning of the twenty-first century, buoyed by a decade of extraordinary catches, fishermen like Bruce Fernald and Jack Merrill didn’t expect the huge hauls to last.

  Bruce and Jack believed they had done their part by protecting egg-bearing lobsters, undersized lobsters, and oversize lobsters, and they would reap whatever reward Mother Nature saw fit to bestow. The lobstermen of Little Cranberry Island felt that if catches declined to previous levels, it wouldn’t be the result of overfishing, but of the lobster population passing through a natural upswing and entering a natural downswing. The study of lobster ecology had given some scientists a similar view.

  The government’s assessment, by contrast, had changed little. The National Marine Fisheries Service still listed the American lobster as “overfished,” and scientists at the agency still recommended raising the minimum size.

  These scientists were actually saying two different things when they used the term “overfished.” One was the problem that most people think of when they hear the word—exploitation of a marine population beyond the point of long-term sustainability. But in the parlance of fisheries science, “overfished” can also refer to the short-term problem of animals being harvested before they have grown big enough—a farmer wouldn’t cut down Christmas trees, for instance, when they’re only a few feet tall. A population can be deemed overfished in this sense even if the prospects for long-term sustainability are good.

  Both types of overfishing worry the National Marine Fisheries Service because the agency is charged, on the one hand, with building fish stocks over the long term and, on the other, with encouraging their efficient exploitation in the short term. It may seem a paradoxical pair of goals. But by increasing the minimum size of lobster, government scientists believed, they could end both types of overfishing. More lobsters would make eggs, and more lobsters would be caught after they’d grown larger. The former would help ensure the long-term survival of the population. The latter would increase the total amount of lobster meat available for human consumption, from the same number of animals.

  After the acrimony between the lobster industry and government scientists peaked during the 1980s, however, state legislatures had circumvented the authority of these scientists, weakening their ability to impose management measures directly. In the 1990s the state of Maine had initiated an experiment called “comanagement.” Government scientists would still determine the overall goals for the fishery, but lobstermen themselves would choose the specific measures that would allow them to reach those goals.

  On Little Cranberry Island, Mark Fernald and Bruce Fernald were elected to the regional council of lobstermen responsible for the Mount Desert Island area. The council voted to cap the number of traps each lobsterman could use at eight hundred, and also to limit the number of new lobstermen that could enter the fishery. The result was a confusing mix of unintended consequences. Lobstermen with fewer than eight hundred traps rushed to reach the new limit—they feared losing out if the cap was subsequently lowered. Meanwhile, teenagers bought boats and started setting traps—they feared losing the chance to become lobstermen later. The overall effect was to increase trapping effort, not decrease it.

  As lobstermen discovered the pitfalls of managing themselves, they also discovered some benefits. The Maine Lobstermen’s Association still opposed raising the minimum size, and the new system of comanagement let the MLA participate directly in the making of policy. When government scientists argued that the lobster population wasn’t producing enough eggs, the MLA countered that V-notching and Maine’s oversize law ensured sufficient egg production. When government scientists argued that a larger minimum size would benefit lobsters and fishermen alike, the MLA countered that raising the minimum size would, by the government’s own calculations, provide only a marginal benefit to egg production while incurring significant risk for lobstermen—consumers might still balk at buying more expensive lobsters.

  On the surface little had changed. But instead of fuming from the sidelines, lobstermen were sitting at the table and casting votes. Instead of fighting for access to scientific evidence, lobstermen had their own science to present. When they took the sea-sampling data they’d helped collect to the National Marine Fisheries Service, and offered to make V-notching mandatory instead of voluntary, government scientists were forced to acknowledge that V-notching satisfied most of their stated concerns about egg production over the long term.

  Ed Blackmore, now retired from his position as president of the MLA, was pleased. An approach he’d advocated for decades had come to fruition. “If fishermen are part of the problem,” Ed had always liked to say, “then fishermen have to be part of the solution.”

  Other New England fisheries—the troubled cod industry in particular—began to look to Maine’s lobster industry as an example. Decades of centralized government oversight of groundfish had resulted in many draconian regulations, but few practical solutions. Cod fishermen wondered whether local stewardship might be a better alternative—for both them and the fish.

  Meanwhile, government scientists continued to refer to the lobster population in the Gulf of Maine as “overfished.” In the technical parlance of fisheries economics the use of the word was justifiable, since raising the minimum size could still result in a higher total yield of lobster meat. But as a description of the biological sustainability of the lobster population, the continued use of the word “overfished” did not reflect the reality most Maine lobstermen saw in their traps.

  Back on Little Cranberry Island, overfishing was the least of the lobstermen’s fears. In 1999 disease had destroyed most of the lobsters in Long Island Sound. No one knew for certain what had caused the epidemic, though explanations included parasites, warm water, overcrowding, and the spraying of pesticides, especially for West Nile virus. For Jack Merrill the danger posed by pesticides was particularly worrying. To demonstrate how similar the nervous systems of lobsters were to those of insects, he helped his daughter with a science project at school. While her classmates watched, she sprinkled a few drops of a household pesticide over a tank containing a lobster. Within seconds the animal convulsed and was dead. To Jack, toxic runoff seemed a far more immediate danger than overfishing.

  Barring such threats, on Little Cranberry Island there was at least one fisherman who thought a natural downswing in lobster catches might be just what the industry needed.

  “I always relish a shakeout,” Warren Fernald would opine with a grin. For him, the discipline imposed by Mother Nature was to be welcomed. “Sometimes scoundrels get into the fishery. After a shakeout they don’t do so well. The guys that have been hanging in there do okay.”

  EPILOGUE

  Hauling In, 2001

  The Double Trouble’s new engine had cost Bruce Fernald twenty thousand dollars, and the whirring monster blasted a well-tuned howl from the exhaust stack as Bruce churned the boat through another circle across the sea. But it was the few hundred bucks he’d spent on a different piece of equipment that had most dramatically improved his efficiency hauling traps. Bruce had fi
nally started wearing glasses. This morning, though, even they didn’t seem to help.

  “Come here, you son of a bitch!” Bruce shouted.

  Jason Pickering, the Double Trouble’s sternman, rushed to the helm with a pained expression on his face.

  “No, no, not you,” Bruce said. “I was talking to the buoy.”

  When a buoy eluded Bruce his tantrums were legendary. Picking out a Styrofoam bullet on twenty square miles of sea pimpled with whitecaps was an incomparable form of aggravation, even with four satellites telling the GPS unit that the buoy was already aboard the boat.

  “Tide,” Bruce said, invoking every lobsterman’s nemesis, “you turned early on me, didn’t you?”

  When the tide is running hard, a stationary lobster buoy looks like it is streaking across the surface, a bubbly wake boiling behind it. As long as the buoy doesn’t get dragged under, it is relatively simple to locate because it gets tugged in a predictable direction—often that is toward shore if the tide is flood and away from shore if it is ebb, depending on local currents. But during the half hour or so when the tide switches directions, the position of a buoy is about as predictable as that of a helium balloon on a hundred-foot tether in a shifting breeze.

  A tide calendar would tell you that the sea floods toward land for six hours and six minutes and then reverses direction and ebbs for the same length of time, this cycle occurring roughly twice a day. During a strong flood or ebb tide, a string of buoys ought to behave like a row of balloons in a steady wind, each tied to a brick, strings pulled taut at an angle. A helicopter pilot, having dropped the bricks single file in line with the wind, could circle back and fly straight into the wind, pick up each balloon, and keep flying while he reeled in the string and approached the brick underneath, and so on for the next balloon and brick. Bruce liked to haul his traps in a similar way. Whenever the terrain of the seafloor allowed it, he set his strings of traps more or less parallel to the flow of the tide. When it came time to haul them a few days later, he’d drive the boat into the oncoming current and haul the row of traps from downstream.