by Carl Safina
By the time we’ve finished loading, the boat has become the usual expeditionary disarray of heavy coolers, cases, wet suits, air tanks, rain slickers, gasoline tanks, and scientific gear. Overhead, it looks as if rain could spoil the shoot. We all pile in anyway, adding Mitch at the last moment, pushing away from the dock just as a brief drizzle begins. We thread our way through the cuts in Tern’s reefy barricade, maneuvering our boat through the black pinball-bumper lava heads to the open turquoise lagoon. My binoculars reveal that the bursts of white erupting from a calm sea beyond the reef are Spinner Dolphins in their highspiraling exuberance. A six-mile lagoon crossing puts us in the green shallows just off East Island.
Everyone tells us dawn is the best time to look for sharks here at East Island. But prepping and getting here has taken until almost eleven. Sharks or not, there’s plenty to see anyway. Fully half of all the sea turtles throughout Hawaii come to this one island to nest, and here they are. Their dark, lumpy forms are bobbing and gliding in the shallows. The shoreline is tractored and trod with the activities of nesting turtles. Many sets of turtle tracks go straight up the steep beach, where the dry-shelled turtles look like terra-cotta sculptures on the white sand. They’re mostly sleeping, heads down, looking dormant. Those just coming ashore, wet and gleaming, look absolutely gorgeous, with starburst shell markings of tan, beige, and dark brown. The island above the beach looks like it’s been shelled by artillery, with thigh-deep body pits that the turtles have dug. They must raise havoc with ground-nesting birds as they bulldoze through their colonies each night. At one end of the island, an amazing sight: so thick are the sleeping sea turtles, I count twenty-six in a fifty-yard stretch of beach. Some are coming and going up and down the beach.
There’s something inexpressibly melancholy about the way a sea turtle moves on land. Their normal activities seem to require unbearable exertion and forlornly heroic effort. Shove and stop, lurch and pause, they row themselves through the oceans, and they row when they’re ashore. They row, row, row themselves through the decades of their long, improbable, ancient life.
East Island is higher than Tern and didn’t get flooded or washed over in February, so the albatross chicks are pretty numerous on this island. Big juvenile albatrosses—full-sized, almost fully feathered and nearly flying—line the berm. (In almost all birds, the young are adult-sized by the time they first fly, their skeletons fully grown.) You can see a lot of waving wings, even from a distance. Though occasional gusts unsteady them, they savor the excitement and persist in leaping and flapping.
To rest and breed—Green Turtles and Monk Seals
Seals populate the beach too. A mother and pup doze peacefully. One lone little black-velvet pup, permanently stilled, is a boon to flies. Another mother seal has taken her pup into the water along shore—a risky place. She keeps putting her head in the water, scanning back and forth, probably watching for sharks. Another large seal on the beach has a bloody wound near its tail, perhaps from a shark, perhaps from a fight with another male. One just-weaned seal that came ashore last night has a hideous, gaping wound on one side—and this is certainly a shark bite. The wide crater it left—about one-third the length of its torso—is through the skin, through the blubber, and well into muscle. It is difficult to comprehend how this seal is still alive, yet it seems alert. Almost certainly, this wound is fatal. Perhaps the best to be hoped is for this seal to experience the onset of shock, to mask its misery until the mercy of death. Evolution breeds majesty and misery in equal proportion, and usually in very close quarters.
Mitch says this pup’s mother had left it prematurely weaned. In addition to the loss of parental protection, the weaner’s low weight, inexperience, and small size left it ill-equipped for survival, and at high risk of starving. So the question presents itself: Are sharks fully responsible for the death of this seal or—in this instance—did sharks attack a seal already doomed to starvation by early separation from its mother?
French Frigate Shoals has more such shark attacks now than, say, ten years ago. But most of the seals they hit are low weight, less likely to survive anyway. More seals are starving now than ten years ago. So is it a shark problem? It depends on your perspective. Bill Gilmartin, a Hawaii-based scientist whose research of Monk Seals spans more than two decades, says, “In my mind it’s a food problem, causing seals to be skinny and vulnerable to begin with.”
ANY DAY NOW, as soon as the first chicks begin taking their first flights and landing in the lagoon here, Tiger Sharks will turn their attentions on just-fledged albatrosses bobbing on the surface. They will be like trout gulping mayflies, but on a vastly enlarged scale. So, like trout fishermen, we will “match the hatch” by luring Tigers with albatross carcasses. We go ashore, looking for dead birds.
We nudge the boat in close, wading ashore through the turquoise shallows, trying to be vigilant for shadows in the water. The soft coral sand tends to be powdery when dry, a bit sticky when wet. A lot of the sand is bits of pink and purple coral or shell. Keeping our distance from the seals and turtles, we collect the carcasses of several almost-grown albatross chicks that have recently died. A blue plastic laundry basket, washed up on the beach, becomes a bird mini-morgue.
We move off, about a hundred yards offshore. Our anchors travel about fifteen feet to the bottom of the bright aquamarine lagoon. From here you have a nice, commanding view of the beach and surrounding waters. A rocky reef extends from one end of the island. Right beyond the black reef’s white breakers, the atoll’s lagoon plunges deeper, abruptly turning blue. Beyond that, the pinnacle stands like something from a Lost World landscape. Two Eagle Rays come to the surface, splashing and thrashing. This is their breeding season as well. We tie the boats to each other so they will remain just a short distance apart.
Scarcely have our boats come tight on their anchor lines when a large Tiger Shark appears suddenly next to us, its dark form gliding in a tight, taught semicircle. The unexpected sight creates instant commotion. It vanishes, but all of us sense that sighting a shark so soon promises further excitement. After we regain our composure, Brad ties the basket of birds overboard at the stern cleat, to start our shark-attracting slick. The dead birds are in various stages of decomposition, from freshly dead to putrefied. A smelly slick immediately begins forming around the boat, but there’s no current to speak of. In my shark-fishing experience, you need either a fast drift or a current. If the slick just forms around your boat rather than streaming away and spreading the scent, your chances of attracting sharks decline. And fresh bait works much better than rotten bait. But we’ll see what happens. Obviously, there’s at least one monster shark lurking nearby.
To eliminate the trauma of capture, the researchers want the shark to simply swallow a transmitter in a bird carcass. The shark will eventually, after some passage of days, regurgitate the transmitter. Greg expresses to me some uneasiness about using bird carcasses for bait. He feels it could seem disrespectful to the birds. I tell him it’s aesthetically ungraceful, but I see no ethical problem with it; it’s a natural food for sharks, the birds were already dead, and they’re being used by scientists to learn something about sharks.
As Greg considers his first shot, Birget wires Brad and Chris for sound. Then she suits herself up with headphones and microphone boom, and checks all of her sound equipment to make sure everything is working. The first scene will show Chris and Brad setting up by putting a transmitter inside one of the dead birds, putting the bird carcass overboard at the end of a line, and checking the transmitter signal. Chris puts the hydrophone overboard. This is a palm-sized, wedge-shaped metal device. When the ultrasonic signal from a transmitter hits its face, a series of crystal-forming ceramic elements vibrate at a frequency corresponding to the sound. That signal is sent through a wire up to the receiver, shifted into human hearing range, and amplified. The wire runs from the hydrophone through a hollow handle attached by a swivel bracket to the side of the boat. Brad turns on the tracking equipment and tests two
transmitters on different channels. The receiver, which is housed in a cooler to keep it shaded and dry, responds with rhythmic chirps. Bill sets up, turns the camera on, focuses, and says he’s rolling. Birget turns on the sound tape. Greg snaps his moviemaker’s slate to synchronize the sound and the film.
Brad picks up a bird, opens its bill, and with a gloved hand puts the transmitter down its throat. Then he tosses the tethered, transmittered albatross directly toward us. It’s a strange sight—the dead albatross flying through the air at us, landing upside down on the water with a heavy splat, its enormous black wings splayed, its breast afloat like a black football. Ironically, this poor dead bird is the first chick in the colony to fly over water.
The bird carcass drifts astern on its line. When the shot is done, Bill says, “Good thing the stink doesn’t get captured on film. That bird is definitely not ready for prime time.” Brad and Chris, standing widelegged on the boat’s benches, watch expectantly and hopefully, searching the hemisphere of vision astern. Greg says, “Chris, just talk about why you’re here.”
Bill and Birget get rolling, and Chris launches: “Tiger Sharks have been considered culprits in attacks on Monk Seals here. Monk Seals are endangered, and wildlife managers have actually considered culling or thinning the Tiger Shark population here. But we know nothing of their movements here, or even how many there are. In other places, Tigers seldom visit the same sites two days in a row. Are the sharks here residents? Do they patrol the same areas daily? Brad and I, as shark scientists, would really like to find out. So would Monk Seal scientists. We’re hoping to get a shark or two to swallow a transmitter, so we can begin to learn their habits here. If this pilot project is successful, we’ll come back with surgically implanted tags, and put out listening stations that can detect sharks’ movements over the course of a year or so. Basically, we would like to get a handle on what the sharks’ movements are, and whether there are patterns.”
Bill keeps rolling a few more seconds, then says, “Very good.”
Greg agrees. “Great. O.K., guys—bring the sharks in now.”
Chris starts scanning with binoculars, a sign of avid impatience.
Off camera, Brad says, “Everybody’s worried about Tiger Sharks eating their study animals; the seals, or the turtles, or the albatrosses. Well, the sharks are our study animals. The sharks are out here swimming around trying to survive, trying to have their babies, trying not to get caught and have their fins cut off for soup—”
Chris points to something in the distance. We all look.
It turns out to be “just” a turtle.
WHEN NOTHING FURTHER happens after quite a while, we move near the end of the island, where runs the long shallow reef with breakers, bordered by a crisp line of blue, deeper water. There’s a current here, and the stinky slick from the dead birds immediately begins streaming away. These seem like better conditions for drawing attention.
Within ten minutes, I see a dark shape. I watch it for a few moments to make sure it’s not a turtle. Not a seal. The word “shark” snaps everyone to attention.
The imposing shadow of a large Tiger approaches the boat. It is mellow of mood, and everything about its calmness is frightening and charismatic.
Bill gets his camera to his shoulder.
The shark is quite a grand one. It looks ten feet, three very heavy-bodied meters of flexing, flowing muscle. It angles away, goes downcurrent about a hundred yards, and makes a long, lazy circle back. The shark seems indolent and not actively hunting, almost as if we interrupted its afternoon siesta with an interesting scent it felt obliged to investigate.
The shark’s confident silhouette, slowly weaving back and forth, begins another long, gradual approach. Death itself could hardly seem less hurried.
A subtle dark form when it first appeared, it now looks utterly striking, its shape and shadow in high contrast against the aquamarine lagoon. It moves in a little closer to the boat, then passes.
Bill is rolling.
The shark makes several wide circles beneath the dead albatross. It moves downtide, just a little, then lines up for a direct approach toward the serenely bobbing corpse. Planing upward, its dorsal fin slices into the atmosphere, then in startling slow motion its enormous square head bursts into our world, pushing a pile of water over the bird like a snowplow. The massive mouth opens for a calm gulp.
But surprisingly, the bait remains untouched as the Tiger passes and continues beyond our bow, its beige-brown body vanishing against the darker reef.
Will it reappear? Hopeful anticipation winds tighter as seconds pass.
Brad points suddenly. The shark appears again against the turquoise bottom, about a hundred and fifty yards astern.
Greg says, “It looks big.”
Brad, absorbed in the sight, nods quietly. “It’s a decent-sized shark.”
Slowly, always slowly, it comes back, its dorsal slitting the surface. I’m not into stereotypes, but this is classic.
The shark slides directly under our boat, swerves around, and heads straight up.
Bill curses that his film’s run out. Brad jerks the bird to the side at the last moment, stalling for time to let Bill change film. The shark passes, pivots, and charges back fast. Brad, like a marine matador, pulls the bird up out of the water, and the shark swings past. I have an urge to shout Olé!
Bill resumes rolling as the shark comes on again. Brad flips the big bird right where Bill can get the best shot.
The shark glides in. Very close. Right alongside. As it flows past, we can see the faint, blotchy side bars that give the Tiger its name. We can see that it’s a female by the configuration of the fins on her belly. Greg says, “Lovely animal.”
Between passes, we begin noticing more and more water in the boat. I begin looking around, trying to figure out where the water could be coming in from.
The shark comes back, and Bill continues filming. As the shark turns away, there seems to be a lot more water, and Greg announces, “Guys—I think we’re sinking.” If any time for sinking is better than any other time, this is not the best.
The ten-foot Tiger slides alongside us again as I grab a bucket and begin bailing. And suddenly all three of us realize that every time the shark comes by we all crowd to one rear corner of the boat for the best view, dipping the stern low enough to let water in around the outboard engine.
Abruptly the Tiger comes head-up out of the water. Greg asks excitedly, “Bill, are you in tight?”
“Real tight,” Bill says. “I’ve got nostril and eyeball.”
The Tiger’s protective eyelids close as its mouth covers the albatross. Brad yells, “She’s got it now!” The Tiger turns and angles down, stretching the nylon cord tight against Brad’s straining grip. Twisting, its white belly flashing, the shark takes the taut line hissing across the water, ripping it through Brad’s fingers.
Then the Tiger suddenly thrashes to the surface, its dorsal knifing up, its slashing tail lashing. Working and worrying the carcass, it tears the bird in half.
“Tiger Sharks often seem clumsy,” Greg says. “But at other times they can be incredibly dextrous.”
Chris agrees. “When they really need to, they can be very”—he searches for a word—“articulate.”
The shark circles back immediately, thrashing the water, shaking the carcass, pulling down the second half of the bird. Part of the corpse bobs to the surface again as the Tiger comes directly past our stern. For all the commotion, we get the feeling that it’s just fooling around, being dainty compared to what this creature is capable of doing. Up once more, it takes the bird’s last remnants in one fluid gulp, leaving a smear of oil and a trail of black feathers.
The shark has vanished. But it has swallowed the transmitter, and Chris has the signal on the hydrophone. He points in the direction of the unseen shark. Chris says tersely, “Gotta boogie; let’s go.” These transmitters don’t work over distances of more than about half a mile. You have to keep following, and the fish ca
n give you the slip pretty easily.
Now it’s a race to keep up with the shark. Yet our engine needs to be convinced that we really do need to move. Chris has trouble getting the outboard started, but on the fifth pull it kicks to life. Chris sits hurriedly and hits the throttle to go chasing, and the outboard dies immediately. It’s critical now to keep up with the shark, but we can’t get the main engine started, and even the spare “kicker” won’t cooperate. Chris again pulls the cord on the main engine, and finally it roars.
With Chris at the helm, Brad is swiveling the hydrophone, trying to determine the shark’s direction. This requires finesse. It’s not easy to hear fine changes in the strength of the chirps coming from the receiver. With Brad pointing, Chris steers.
This is where the science begins. Many months of preparation, coordination, and logistical arrangements are suddenly paying off in this moment. Brad says, “This is exciting, isn’t it?”
Chris says, “For me, all the stuff I go through, all the work, grading all the papers, the committee meetings—it’s all for one thing: to be here doing this right now. This is why you go through all the other inanity.”
“And just think,” Brad adds. “We’re probably the only people in the world who are tracking a Tiger Shark right now.”
“Probably?”
“Scientists always say ‘probably.’”
Besides following, we must record the shark’s track. Chris gives the tiller to Brad. Sitting with his clipboard on his knees, Chris consults a handheld satellite GPS on the bench beside him and starts mapping exact latitude and longitude positions and directionality every ten minutes. Now Brad has a dual job: one hand on the tiller, and the other on the hydrophone. He turns the hydrophone slightly to get the strongest signal and steers the boat to follow.
