One burly six-foot-six scalloper walked up from the back of the room and, with a look of amazement, touched the screen where a rocky crag was displayed. "I always thought it looked like this," he said. "Now I know."
Mayer, currently head of the University of New Hampshire's Center for Coastal and Ocean Mapping, assembles these images by scanning the seafloor with a technology called multibeam sonar. To measure the depth of the ocean, most boaters send a single beam of sound to the bottom; depths correspond to the time it takes the echo to return. But multibeam systems send dozens, even hundreds, of beams simultaneously, allowing mappers to construct 3-D maps of the seafloor. Mayer's underwater map of Portsmouth, New Hampshire, is so detailed that in some areas individual lobster traps are clearly visible 60 feet below the surface. He's also helped modify a multibeam system so that fisheries officials can detect schools of herring and, based on the characteristics of returning sonar beams, distinguish between soft, sandy surfaces and harder, rockier bottoms that attract different fish.
The scallopers were so impressed with Mayer's maps that one of the larger companies purchased a million-dollar multibeam system of its own and has used it to identify the gravelly bottoms that scallops prefer. This has allowed the company to fill its individual, government-imposed scallop quota in a quarter of the time it used to take, while dragging their dredges over a third as much bottom, reducing collateral damage to other organisms. Mayer warns, however, that because multibeam increases humans' ability to fish more efficiently, getting meaningful regulations in place is more important than ever. "If you did this without firm quotas, it would be a disaster," he says.
But the new technologies are of enormous benefit to marine ecologists like Robert Steneck, who has long struggled to understand the relationship between the American lobster and its habitat in the Gulf of Maine. A professor of marine biology at the University of Maine's Darling Marine Center, Steneck also happens to be one of those scientists who thinks that to understand the marine environment, you have to get wet. Today Steneck, a short, confident man with a distinctive red beard puts on his scuba tanks, dry suit, mask, and fins and stands at the rail of the Darling Center's research launch. "Ready?" he asks me, then steps overboard into chilly gulf waters.
The American lobster is the state's most important commercial marine species, mostly because, unlike almost every other species here, it is actually thriving. Maine's record-breaking catch of 57 million pounds in 2000 was nearly triple the typical annual catch of the 1960s and 1970s. Steneck thinks the reason may lie on the bottom of the ocean.
Off the islands of South Bristol, Maine, Steneck leads me on a tour of prime lobster habitat. Drifting along amidst kelp-covered boulder fields, he catches lobsters under just about every stone he overturns. He's got his technique down, faking out the lobsters with one hand, then grabbing them by their back with the other as they lunge the wrong way. As we float along over cobbles and eel grass meadows, Bob hands me one lobster after another, pointing out their particular attributes: size, gender, and how close each is to shedding its shell. We find lobsters everywhere -- hidden under rocks, peeking out of little fox holes dug in the sand, even hanging around a lobsterman's trap. Indeed, in surveys of the types of bottom habitat favored by these crustaceans, Steneck and his colleagues have found an average density of baby and juvenile lobsters of more than one per square yard, an amazing figure for such vast areas of seafloor.
Statistical models offer no explanation for the ongoing lobster boom; in fact, every year, scientists at the government's Northeast Fisheries Science Center in Woods Hole, Massachusetts, insist that American lobster stocks are on the verge of collapse and that the fishery needs to be tightly controlled -- a point of view that hasn't made them popular with Maine's lobstermen. "The managers were telling me that the lobsters weren't that abundant and were in decline," Steneck recalls. "But I'd go diving and I'd see all these lobsters."
By studying lobsters with the help of fishermen, sonar, satellites, submarines, and even a vacuum cleaner that collects the babies, Steneck and his colleagues are discovering that subtle natural factors -- ocean currents, water temperature, wind direction, and the composition of the seafloor -- are powerful influences on the abundance of stocks. It turns out that lobster larvae can float great distances on coastal currents before settling to the bottom in search of hiding places. Steneck thinks the robust lobster population may be due to a shift in currents, which are carrying lobster larvae to rocky nursery grounds like those off South Bristol, rather than to the deep, muddy bottoms where they would be quickly eaten by roaming predators.
This is just the sort of ecological hypothesis that mathematical models could never have come up with. How could fisheries scientists really understand the lobster's breeding cycle when they didn't even know where lobster habitat was? In this regard, Steneck's team was ahead of its time. Back in the mid-1980s, they decided to find the nurseries and took the then-unheard-of step of asking the fishermen themselves for help. Lobstermen saw undersized and ovesized lobsters every day in their traps, and had a pretty good idea of where and when to find them. "We'd ask lobstermen if we could come along and tag and measure the ones bearing eggs," he recalls. Steneck's work has done much over the years to mend the traditionally hostile relationship between scientists and Maine's lobstermen.
"Now we've got a great bunch of scientists in Maine who come out on the boats with us and are not up in their offices making up data," says lobsterman Pat White, who has been taking scientists to study sites off York for more than a decade. "They go out of their way to explain what they're doing and what the benefits of that knowledge can be."
fter chasing lobsters around the seafloor, Steneck and I head back up, passing through a slow motion blizzard of nutrient-rich algae and other detritus. Bobbing on the surface, you wouldn't know that the bottom of this narrow island channel, aptly named the Thread of Life, is prime lobster habitat. Something else becomes clear: You wouldn't want a big fishing trawler to drag its heavy gear over the bottom here. A trawler's doors would level the kelp and sea grass, roll the boulders and cobbles, crushing lobsters and other creatures hiding underneath, laying waste to this hive of activity. There's no risk of that happening in the Thread of Life; the passage is just too thin and shallow to bring in a large vessel. But in the open waters of the Gulf of Maine, the only thing that's preventing the destruction of other ecologically vital areas is the fact that they are currently closed to fishing for bottom-dwelling species. People are asking what will happen years from now, when fish populations finally recover.
Conservation groups and a growing number of scientists are pushing for a network of marine protected areas which would, in effect, zone the seafloor much as people already zone activities on land. Multibeam surveys and GoMOOS make it much easier to determine where a given activity is appropriate. Some areas might be off-limits to bottom trawling, and others might be closed during certain seasons to protect fish as they spawn or lay eggs. A few would be full-fledged marine reserves -- closed altogether to protect important habitats from disturbance.
Meanwhile, ocean observing systems are set to start spreading to other waters. One is underway for the Gulf of Alaska, largely paid for with funds from the Exxon Valdez settlement. A handful of congress members, including Maine's Olympia Snowe, are pushing a plan to create a federation of observing systems that would monitor most of the U.S. ocean realm, which extends to 200 miles off our shores and islands, including Hawaii, Guam, and the Aleutians. The proposed system would incorporate GoMOOS and would cost some $200 million a year to operate, but would generate six to 10 times that amount in savings by reducing the costs of natural disasters, improving search and rescue, and adding to our knowledge of marine habitats and fish stocks. GoMOOS alone is expected to have a return of $33 million a year on a $3 million budget, and its head, Philip Bogden, thinks that will win over legislators. "If you give me a buck and I give you ten," he asks, "are you going to do it?"
Outside Bogden's office window, trawlers and oil tankers pass by the Portland waterfront, churning up a white froth on the harbor's gray surface. Suburban commuters speed overhead across the Casco Bay Bridge, dashing towards their Cape Elizabeth homes with scarcely a glance at the ocean below. But somewhere over the horizon, Buoy E has silently snapped to life once more and phones home with the latest news.