Demon Fish (28 page)

Scientists do not yet understand why this happened, but it highlights an incongruous fact: the predator Americans have fixated on for years has been much closer to us than we have realized. And beyond the question of great whites’ lineage and migration patterns, the work of these scientists suggests that sharks may not interbreed with their own kind across ocean basins, which means they may be more vulnerable than previously thought.

Block still doesn’t know how the white sharks managed their travels with such exactness. “Are you born with this node in your head?” she wonders. “These sharks are coming back with such precision to these areas. They do it with whatever they have in their brains.”

After making this discovery, Block and several of her colleagues have pushed their research even further by counting the number of individual white sharks that spend their time in the northeast Pacific. While these animals are notoriously elusive, the UC Davis marine biologist Taylor K. Chapple and six other researchers had two things working in their favor as they embarked on this daunting task of identification: The trailing edge of a white shark’s dorsal fin, like a human fingerprint or a humpback whale’s fluke pattern, has unique ridges and indentations that become worn over time and can be used as a form of identification. These white sharks spend a good amount of time at the surface investigating prey, allowing the researchers to photograph and identify them. By feeding this information into a sequential Bayesian mark-recapture algorithm, researchers have been able to estimate white shark abundance off central California.

The results are stunning: scientists identified 129 whites by taking 321 photos, and concluded there are roughly 217 individual great whites swimming off central California. It is, in the words of Chapple and his co-authors, “an order of magnitude smaller than populations of other large marine and terrestrial predators currently protected internationally.”
²⁰
Until scientists learned how to count great whites, they had no idea how their ranks had dwindled.

On one level, the new research suggests this population of white sharks may be more vulnerable than previously thought. On the other hand, the fact that more than two hundred top predators are thriving off the West Coast provides further proof of what Block had suspected for years, and shared with me as we sat in her office, looking out over the water: “Right out there, it’s the Serengeti. We just can’t see it.”

Even less stunning areas than California’s central coast boast a bevy of sharks. New York’s waters, for example, serve as home to at least two dozen species. They range from some of the most fierce—great white, bull, and tiger sharks—to lesser-known ones, like finetooth, chain dogfish, and silky sharks.

It is hard to appreciate something invisible to the human eye. But if we could see the ocean for what it is—a vast expanse of wilderness, filled with even more extraordinary creatures than those roaming the African plains—we might begin to value it for its true worth.

7

LIVING WITH SHARKS

We see white sharks as an asset and a value.

—Gregg Oelofse, head of environmental policy and strategy for Cape Town, South Africa

T
he more scientists understand about sharks—the modest threat they pose to us, and the grave threat we pose to them—the harder they have worked to carve out places in which these animals can survive unmolested. In many ways marine biology is at a pivotal moment, when we are discovering the richness of the ocean at the very time we are grasping how we’ve managed to deplete it over the last few centuries. Preserving what’s left, as well as rebuilding parts of it to a semblance of what it used to be, requires us to relinquish some of the power we have exercised in the past. It requires living with sharks.

There are places across the globe where sharks still thrive. And these are the places where humans must negotiate a different path with them, to ensure these animals still have stretches of sea to dominate. The very act of finding them is just the beginning.

Amid the undulating wave of sea grass, a glittering eye suddenly appears, reflecting the glare of our flashlights. This three-foot-long specimen of
Hemiscyllium freycineti
—better known as the Raja Ampat walking shark—shimmies across the seabed, using its pectoral fins to propel itself forward. But then Mark Erdmann—senior adviser for Conservation International Indonesia—reaches for it, and the flash now comes from its teeth as it hisses and struggles to escape the scientist’s unwelcome embrace.

Hemiscyllium freycineti
has existed in this corner of the world for millennia, tucked away in a bay that’s allowed it to evolve separately from other sharks a matter of miles away. The Bird’s Head Seascape—an area on the northwest tip of the island of Papua named by Dutch cartographers in the nineteenth century for its distinctive shape—boasts a myriad of unusual creatures like this one, and it has recently become known as a sort of lost world, where most underwater trips regularly turn up species new to science. Within the Bird’s Head Seascape sits Raja Ampat, a series of 672 islands whose name—Four Kings—pays homage to its four biggest ones, Waigeo, Batanta, Salawati, and Misool. It is, in Erdmann’s words, “the crown jewel” of the region’s biodiversity.

Since Conservation International launched an expedition here in 2001—the first major scientific survey of the area in decades—researchers have cataloged 1,350 fish species in the Bird’s Head Seascape, along with 700 mollusks and more than 540 species of hard coral. (That’s ten times as many species of coral as in the entire Caribbean and means that nearly 70 percent of all known coral species on earth reside here.) Gerald Allen, an ichthyologist and Conservation International consultant, identified 335 different marine species in a single dive, setting a world record, and in one six-week period in 2006 Erdmann’s expedition discovered 50 new species.

Allen, who co-led the first CI expedition in 2001 after spending three years waging “a one-man campaign” to get conservation groups to pay attention to the area, describes that first trip as “everything that I dreamed of, and more. It was like stepping back in time two hundred years and being on one of the first expeditions to New Guinea.”

The fact that this far eastern spot in Indonesia has just emerged this decade as a sort of marine biologist’s Shangri-la is a function more of politics than of science. The Dutch colonized the region, along with the rest of Indonesia, in the eighteenth century, and European explorers began investigating it in earnest in the early nineteenth century. While scientists made a flurry of discoveries during the turn of the nineteenth century, these petered out as the Dutch tightened their hold over western New Guinea. When Indonesian authorities won back the area in 1962, they were just as reluctant to let foreigners in, which meant that exploration was at a standstill at the very time when the advent of scuba diving was allowing scientists to conduct studies at unprecedented depths. The sharks were here, but untouchable.

Across the globe, researchers are using new technologies to expand our knowledge of sharks in radical ways. Over the last decade these discoveries have changed our understanding of everything from how sharks feed, mate, and travel to what forms of them exist. And they have made once-remote places like Raja Ampat a living laboratory.

There are plenty of different kinds of fish in Raja Ampat, but that doesn’t mean it’s easy to figure out which ones are new to science. Some researchers, like Gerry Allen, have an incredible capacity to ferret out this sort of information. Before working for Conservation International, Allen served for two decades as the curator of the Western Australian Museum, and he’s described more than four hundred species during his career. Many tourists to tropical isles have read his work without even knowing it: he’s the lead author of the alluringly titled
Reef Fish Identification: Tropical Pacific
, the book that sits in the common room of most diving resorts. Using a slate with waterproof pages underwater, he usually gazes at the fish swimming around him and scribbles down their scientific names without looking at his writing tablet. While most divers rely on these tablets to communicate among themselves, Allen often uses them for note taking. In some instances, however, he even forgoes the tablet and relies on his memory instead.

“Gerry Allen,” wonders Max Ammer, a Dutchman who runs a couple of eco-resorts in Raja Ampat. “He dives and then he takes a shower, sits down and then writes down every fish he has seen from his head. And he does this twice a day, and sometimes he can do that three times a day.”

About five years after Ammer settled in Raja Ampat, he convinced Allen to come and take a look at the region’s riches: this, in turn, helped inspire Conservation International to launch its first expedition there in 2001, with Allen at the helm. Erdmann made it to the region for the second and several of the successive expeditions, helping Allen chronicle what was there. While the scientists came back from each journey with an array of new species to show for it, the grueling schedule took its toll. Most of the time they focused on looking for species when it was light: in February 2006, Erdmann, Allen, and their colleagues were diving in Cenderawasih Bay as many as six times a day, leaving them exhausted by nightfall. One evening, however, Erdmann decided to enter the water to record nocturnal species that tend to hide during the day.

“I found an epaulette shark, pretty much right away,” Erdmann recalls as we traverse the Dampier Strait in his speedboat, surveying the Raja Ampat region. “It struck me as being quite different from the only known epaulette from the Bird’s Head region, so I pinned it down and swam with it back to the ship. By the time I got back, Gerry [Allen] was asleep, but I woke him to examine my find. Clearly not amused at being awoken, he dismissed my shark as
Hemiscyllium freycineti
, the Raja Ampat epaulette shark described by explorers in 1824, and told me to throw it back. I decided to keep it overnight, alive in a large cooler full of water, so that he could examine it while in a better mood in the morning.

“The next morning, he agreed that the shark did have an unusual spotting pattern, and decided we should at least photograph the animal for a permanent record. We sedated the shark with clove oil, returned her to the seafloor, and took photographs of her from every possible angle. As she awoke from sedation, I scribbled on my slate to Gerry, ‘Should we keep her?’ He hesitated but wrote back, ‘I think it’s just a Raja Ampat shark. Let it go.’ ”

It was only after the two men emerged from the water and started comparing their photographs to images of epaulette sharks on Allen’s computer that they realized the shark they had just set free belonged to a different species. “Basically, he made me release the only specimen we had,” Erdmann recalls. “It was sort of a bummer.”

Later that spring Erdmann and Allen returned to Raja Ampat for the fifth research expedition, this time to Triton Bay, another part of the region. One night during a dive Erdmann spotted another epaulette shark and went after the fish with a vengeance: “I went down and wrestled the damn thing out of the cave. This time we didn’t let it go. I put it in the ship freezer. I took a syringe and pumped it full of formaldehyde.”

Sure enough, the shark was a separate species from the Raja Ampat walking shark. But it also looked different from the shark Erdmann had captured and released a few months before. Now Erdmann had no choice but to return to Cenderawasih Bay.

With his wife, Arnaz—an experienced diver herself—in tow, Erdmann took a seven-hour boat ride to Cenderawasih Bay in the fall of 2006. They immediately found a couple of specimens and brought them back to Bali, where they live. The most reliable way to identify sharks is to count their vertebrae in an X-ray, so Erdmann schlepped the dead shark to a bunch of hospitals in town. Unsurprisingly, he was turned down. “They didn’t want to x-ray my shark,” he confides with amazement. Finally, he lucked out with a veterinary hospital, and they determined it was, in fact, distinct from either the Triton Bay shark or the one discovered more than a century ago. The fact that Cenderawasih Bay boasted an entirely different epaulette shark spoke to the region’s topography as well as the animal’s physical limitations: since it couldn’t swim long distances, it didn’t venture far out and interbreed with other sharks. Over time, it adapted to its narrow corner of the Bird’s Head Seascape, with its own unique features.

Erdmann was pleased to have identified the new shark species, especially since it had eluded him months earlier, but he did not see his discovery of two new shark species as more remarkable than other expedition finds, such as a new lionfish, damselfish, and dottyback. By September 2006 he was helping Conservation International’s press office come up with a press release and telling them about the different species they could tout in the media package. “I don’t think anyone paid a lot of attention to the shark at the time,” he recalls. “I told the press office about the video we had of the walking shark and they were like, ‘
Walking shark?
’ ” It was a fish made for marketing.