War of the Whales (6 page)

Balcomb broke down their search and retrieval area into a grid of ten-by-ten-mile squares. Their plan was for Claridge, Ellifrit, and the Earthlings to survey the Abaco coastline in their inflatable research boat while Balcomb searched the shores of the small Out Islands from the air. Balcomb’s last call of the night had been to a pilot friend, Bill Anspach, who agreed to pick him up at dawn.

After nudging Claridge awake and getting only a groan of farewell, Balcomb forced himself out of bed. He lumbered past a cluster of Earthlings who had crashed on the living room sofas and gathered up the camera gear, binoculars, and notepad he’ d piled by the door the night before. Anspach and his plane were waiting on the dirt strip, just a stone’s throw from the house.

As soon as the single-engine plane lifted off and veered toward the sunrise, Balcomb felt the anguish of the past 24 hours drop away. He loved flying, particularly that first rush of pulling away from earthbound gravity, when everything receded into miniature below. For a moment, at least, the pall of stranded whales gave way to the excitement of the scavenger hunt. Balcomb was a lifelong beachcomber and whalebone hunter, and he couldn’t suppress his excitement at the treasure trove of specimens that lay in wait.

Balcomb never savored the Bahamas more than from the cockpit of a small plane. Flying just a few hundred feet above Providence Channel, it was easy to see what made the Bahamas such a magnet for scuba divers and marine biologists. The waters are the most transparent in the world, with visibility of more than 200 feet. The 30 low-lying islands and hundreds of smaller cays of the Bahamas were once underwater coral reefs that became dry land when the sea level dropped following the last ice age, 20,000 years ago. Ringed by pink and white sand beaches, the islands barely peek above sea level. From the air, you could see where the pale turquoise of the shallows shifted quickly to the royal blue depths of Great Bahama Canyon.

Canyons on land are created by the steady erosive force of rivers. Underwater, it’s the ceaseless gyre of the ocean currents that carve their signature into the seabed. The Bahamas were once joined in a contiguous landmass with Florida and Cuba. Over the course of 150 million years, the Atlantic and Gulf Streams ground away at the limestone ocean floor, creating a 3-mile-deep, 140-mile-long underwater canyon separating the Bahamas from the mainland. The Great Bahama Canyon is the largest, deepest gorge in the world, on land or at sea—twice as wide and three times as deep as Arizona’s Grand Canyon.

Beaked whales have lived in Great Bahama Canyon for 40 million years, ever since they migrated from the shark-infested reefs guarding the Atlantic side of the islands. In the canyon, they found a feeding ground rich with hard-shelled nautiloids that fed on microorganisms near the surface. Before they learned to hunt with sound, beaked whales foraged visually, alongside other whales and fish. To escape predators, their hard-shelled prey descended to the dark depths during sunlight hours, returning to the upper layers at night to feed in the relative safety of darkness.

The upper 600 feet of the ocean is called the sunlight zone, where plants dependent on photosynthesis and the marine life that feed on them live. Below 600 feet lies the twilight zone where almost no light penetrates, even in the transparent waters of the Bahamas. To follow their prey into the twilight zone, and even deeper into the lightless midnight zone below 2,500 feet, beaked whales had to learn to hunt in total darkness—which required echolocating with sound.

Not all whales echolocate. Echolocation, or “biosonar,” was an adaptation that emerged relatively early in cetacean evolution. The fossil record of whales reveals a radical metamorphosis from furry, hoofed land-dweller to sleek marine mammal. Forelegs gave way to fins, hind legs and hair disappeared, tails transformed into flukes, and nostrils receded high onto the head to become blowholes suitable for breathing air at the ocean’s surface. The oceans offered whales a buoyant and spacious home with few predators and abundant food.

Some whales became filter feeders, trapping tiny krill in the baleen brushes of their mouths. Released from the weight constraints of terrestrial gravity, these “baleen” whales evolved into the largest animals ever to roam the world. A 100-foot-long, 150-ton blue whale could consume up to 8,000 pounds of krill in a day.

Other whales, hunting in packs, used their teeth to seize their prey. These “toothed” whales—including dolphins,
^*
orcas, beaked whales, sperm whales, and others—developed the ability to hunt and navigate in the dark using sound, the same way that bats do. Though bats and toothed whales have evolved different specialized anatomy for the task, the principle is the same: they emit high-frequency sound pulses and listen for the echo. The distance between their two ears—which act as separate receivers—allows echolocators to triangulate the precise distance, direction, and dimensions of an object.
¹
Other animals navigate with biosonar. Shrews have been shown to echolocate underground, and blind humans can learn to echolocate by tapping a cane—or simply by making clicking sounds with their mouths—and then listening for the echo from nearby objects.

During their first 10 million years in the Great Bahama Canyon, beaked whales developed primitive biosonar. By bouncing sound clicks off their prey’s hard shell, day or night, beaked whales easily outcompeted the other predators in the canyon who could only hunt by daylight. Their ability to hunt squid at increasing depth drove the beaked whales’ ascent to the top of the canyon’s food chain.

When the hard-shelled nautiloids evolved to abandon their shells to avoid biosonar detection, beaked whales refined their biosonar to echolocate the
internal
structures of the soft-bodied squid—which then developed survival countermeasures including camouflage, shape-shifting, and ink-cloud diversions. Millennium by millennium, the beaked whales improved their sonar to defeat these escape mechanisms and chase the squid deeper into the canyon. This evolutionary pursuit-and-escape minuet between squid and beaked whales continued for thousands of generations, until the whales could hunt squid at depths of a mile or more—deeper than any other predator.
²

To hunt at such extreme depths, beaked whales made several physical and metabolic adaptations, allowing them to dive quickly with a minimum of drag, to tolerate the cold temperatures and crushing hydrostatic pressure at depth, and most importantly, to regulate their breathing to enable deep foraging dives that could last an hour or longer. Other deep-diving cetaceans, such as sperm whales in pursuit of giant squid, have made similar adaptations. But none dive as deep, and surface as briefly, as the beaked whales of the Great Bahama Canyon.

Beaked whales routinely dive deeper than 5,000 feet and remain underwater for more than an hour; the deepest dive ever recorded by an air-breathing mammal was a Cuvier’s beaked whale that descended 9,816 feet in a dive that lasted 137 minutes.
³
Humans can dive only to a few hundred feet without risking decompression sickness, or “the bends.”
⁴
By comparison, a WWII German U-boat reached its crush depth at 860 to 920 feet. Even the deepest-diving of modern military submarines can’t dive as deep as a beaked whale.
⁵

•  •  •

The plane flew due north over dozens of tiny cays offshore of Abaco, many of them unnamed and uninhabited patches of sand and scrub barely poking out of the water. From the co-pilot seat, Balcomb scanned each of the cay’s shoreline through binoculars. For the first hour aloft, he didn’t spot anything.

Just then, as they flew over Water Cay, off the southern bight of Abaco, Balcomb spotted something on the beach. He motioned to Anspach, who took the plane into a steep circle dive and made a low pass over the island. Balcomb videotaped the dark spindle-shaped carcass lying at an angle in the sand, while Anspach noted its GPS position.

As they were taking a second low pass over the beach, a call came in from Claridge over the plane’s VHF radio. She’ d found a Blainville’s behind Cross Harbor. “The sharks must have chased it into the lagoon yesterday,” she said, her voice crackling. “It probably stranded when the tide went out this morning. I can still see the grooves in the sand where it tried to work itself free.” Despite the static, Balcomb could hear her excitement at finding such a well-preserved specimen. “I’ d say it’s only been dead a few hours. Couldn’t be fresher.”

Five minutes later, they flew over the lagoon, and Balcomb could see Claridge, Ellifrit, and several Earthlings hovered over the whale’s body. Anspach set the plane down nearby and Balcomb hustled over to join them.

Just as Claridge had reported, the whale was newly dead. No bad smell or decomposition. Tissue was fresh and firm to the touch. And the carcass was in pristine condition. Not a shark bite on it.

He wanted to get the whale up on dry land where he could take the head and necropsy the organs. The head would tell them if there was damage to the ears and brain, but he hoped that the other organs might also hold clues to what had driven the whale ashore.

The tide was just starting to come back in, so it would be an hour or more before there would be enough water in the lagoon to float the body to shore. Balcomb hated the idea of leaving it exposed to the elements for even a minute longer. The whale was a juvenile, only about 11 feet long. But it still weighed more than 1,500 pounds, and they couldn’t budge it off the sandy bottom of the lagoon. After some rocking and rolling, they managed to get a tarp underneath the whale’s belly, tie a rope around its tail fluke, and tow it out of the lagoon and up onto the beach.

Blainville’s beaked whale that stranded in the lagoon behind Cross Harbor, March 16, 2000. Subsequent necropy and CT scans revealed a subarachnoid hemorrhage and blood in the cochlear aqueduct.

Dave Ellifrit with the Blainville’s beaked whale that stranded at Cross Harbor, March 16, 2000.

•  •  •

It’s shockingly easy to cut off the head of a Blainville’s whale. All you need is the right kind of knife, a strong stomach, and a detailed knowledge of beaked whale anatomy. Balcomb had all three.

He’ d procured the knife, a 16-inch blade with a weathered oak handle, during a research trip to Norway a decade earlier. Scandinavians had been using long-handled flensing knives to carve the blubber off of whales for 1,000 years, but this was a specialty blade designed to cut up large fish and seals. Balcomb called it his “O.J.,” as in Simpson—much to Claridge’s chagrin—and he always kept it honed to a razor’s edge, just in case something interesting washed up on the beach.

Knowing how to decapitate a beaked whale was a hard-won bit of arcana, something he’ d picked up during four decades of roaming the globe in search of
Cetacea: Ziphiidae
. He’ d studied every textbook on whale anatomy, picked through the cutting room floors of whaling stations from California to Japan to Iceland in search of skeletons. While on Midway Island in his late-twenties, he dissected his first beaked whale, a Cuvier’s that had washed ashore dead on a coral shelf in the very middle of the Pacific Ocean. While living in Japan he’ d frequented a family-run whaling station that still hunted the largest beaked whales in the world—the 40-foot Baird’s beaked whales—in the waters outside Tokyo Bay. After the workers were done with their butchering, Balcomb was free to study and sketch the skeleton and internal anatomy. Though the Baird’s whales are twice the size of Cuvier’s, all beaked whales are deep divers that share the same basic anatomy and physiology.

Cutting off a beaked whale’s head can take an hour if you don’t know your way around its distinctive anatomy. Balcomb figured he could get it done in just under ten minutes. The tricky part is figuring out where the whale’s head ends and its trunk begins. All mammals, from giraffes to moles, have seven vertebrae in their necks. But over the course of its evolution, the beaked whale’s cervical vertebrae have fused into a bony mass, creating the appearance of a no-necked creature. Balcomb knew the precise spot to cut in—a foot behind the blowhole, halfway between the eye and the flipper—and how to feel his way with the blade through the blubber and muscle all the way down to the bone. A 16th inch too far back, and the knife can’t sever the cervicals. A 16th inch too far forward, and the blade bangs up against the cranial vault.