by Carl Safina
The shark—unseen, merely heard by the chirps emitted out of the cooler—is running the rocky reef that extends from East Island. A five-foot swell is breaking energetically on this reef, sending white foam sweeping our way. Brad says, “Looks like a washing machine.”
The shark is taking us straight toward the Washing Machine. Now we’re headed directly into the whitecaps, and the boat starts pitching. If the Tiger crosses to the other side of the reef, we must either follow into hazardously rough water or lose her.
Fortunately for us, the shark makes an abrupt right turn toward the open, deeper part of the lagoon. We follow a clear signal.
The other boat parallels us for a few minutes, getting shots of Brad and Chris tracking, while I stay out of sight, lying on the deck watching clouds streaming by, listening to the receiver. Birget radios that they’ve got what they need. I sit up and we wave good-bye as they depart.
The transmitter signal suddenly weakens. Brad’s afraid that the shark might be getting too far ahead. But when he swivels the hydrophone, the strongest signal is behind us. Brad turns the boat around and pulls the hydrophone up, so he can run faster.
After running about one hundred yards, Brad slows and slides the hydrophone down. He begins swiveling the instrument, and looking quizzical. But then the signal comes in clearly. The shark has made a U-turn, heading back toward the reef that extends from East Island.
About two dozen Sooty Terns suddenly and inexplicably gather directly over us, only about ten or fifteen feet up, calling and hovering. I wonder what they want.
Brad says, “In the ancient legends, it is said that when terns gather overhead, one of them is about to—”
One of the terns poops on Chris’s shirt, and they all immediately depart as though they were sharing the prank.
Ten minutes later, the Tiger U-turns again, this time toward open water. Several big clouds sweep over, giving us alternately shade and showers that quickly pass. A Laysan Albatross comes bombing along, sailing straight for the boat, etching the lagoon surface with its long wings, right off our bow, just a few feet away.
Chris says, “Wow, they sure know how to cruise.”
Brad, sounding philosophical, says, “You know, Blue Sharks are the albatrosses of the sea. They have long, winglike fins. They wander great distances searching for food. They’re probably built on the same strategy: to travel long distances looking for widely separated food sources, using a very small amount of energy.”
After traveling out about a mile and turning back, our shark is tight again along the reef, island-bound.
Brad asks, “Can you believe how reef-oriented this shark is? It’s really patrolling the reef.”
Chris responds, “This is what I used to think Tiger Sharks would do, before we did our tracking off Oahu and the main islands.”
None of the dozen-plus Tiger Sharks they tracked in the main Hawaiian Islands ever returned to the same place during the same day or on consecutive days. Those sharks revisited areas very irregularly—sometimes a few days later, sometimes a few weeks.
Our Tiger slides onto a green flat only about five feet deep. It runs into a rocky cul-de-sac and turns around. Now we can see it darkly patrolling the edge of the reef, where waves are breaking.
Brad invites me to take over the tracking. One hand on the tiller, one on the swivel to the hydrophone, I do my best to follow.
A big Ulua streaks in startlingly. It circles around quickly and then strikes the shiny hydrophone—and vanishes. I track our Tiger Shark for about half an hour, then suddenly lose the signal. On the hunch that it is merely outpacing us without changing direction, I pull up the hydrophone and run up ahead at a higher speed. Brad’s silent nod affirms that this is a reasonable action. I’m really hoping to recover the signal; I hate being the one who screws up.
To my surprise and great relief, the chirps return, strong.
Chris says, “Lucky.”
“Sheer skill,” I explain.
Brad asks, “Did you really expect to get the signal back?”
“Of course,” I tease. “Did you doubt me?”
“I wouldn’t have bet my life.”
I poke, “Well, you’re not much of a risk taker.”
Brad smirks at me with one eyebrow raised.
The shark goes along the reef line again and angles back toward East Island. Brad says, “This one is really staying local.”
Chris says, “It may depend on the geographical context. Oahu and the main islands, where we tracked before, is a big area with diverse islands. Here you have this small isolated atoll. And inside this atoll, right at East Island, you have all this fatty, meaty, nutritious food coming here. You’ve got seal pups. Turtles galore. You’ve got big fattened-up albatross chicks. If I were a Tiger at this time of year, I’d be stickin’ close by, too.”
The shark is now heading down along the shore of East Island, cruising by a beach populated by ten seals, including three pups and two weaners. And about thirty-five turtles. Halfway down the island, it turns and begins a long crossing of the wide lagoon.
About two hours later, our Tiger is headed slowly toward Trig Island—still a couple of miles away—where most of the Shoals’ Monk Seals give birth. Hour after hour, we and the Tiger remain connected through the chirps, sometimes fainter, sometimes stronger.
Chris says, “Everybody thinks being a shark researcher is exciting. Actually it’s long, tedious, boring hours.”
I’m thinking, “Compared to what?” but I know he’s kidding.
An hour later, at six o’clock, we’re close enough to Trig to see that the sandy shore is dotted with seals and turtles. About twenty mom-and-pup pairs are on the beach. One mother utters a long, low bellow. Three or four pups have been attacked or eaten at this island in just the last week. Because of the shape of the bites, Galápagos Sharks are the principle suspects. Tiger Sharks’ bite marks are wide and squared off, like their square head.
Suddenly the shark seems to pick up its pace again, and the signal breaks. Chris begins swiveling the hydrophone in its bracket, trying to pick up the signal. He’s listening hard, concentrating with eyes closed, saying hopefully, “C’mon, c’mon, c’mon,” as he turns the instrument in different directions. Chris runs us quickly forward again. It looks as if the shark has given us the slip. “She can’t be moving that fast.”
But wait; there it is, faintly. Chris gets a direction, then lifts the hydrophone and runs again. Now he’s got a faint signal, but steady. We run toward it again, and get it back strong.
“Nice recovery,” I say.
Brad says, “In ten minutes we’ll have a five-hour track. About seven miles.”
I ask, “Is that good?”
He huffs, “Yeah, that’s good! Not as good as fifty hours, like we once had, but it’s good.”
At 6:30, we’re out of time. This lagoon is too full of reefs to safely operate a boat in darkness.
Chris says, “I think we learned a lot today. The first track is always the most exciting because you have no idea what to expect. When we tracked the first Waikiki Tiger we figured we’d just be cruising up and down the shore admiring bikinis the whole time. We had no idea we would be leaving the island of Oahu immediately and going about fifty miles straight to Molokai.”
Brad says with satisfaction, “Today was very interesting. That was uniike any Tiger Shark track ever done before, in the main Hawaiian Islands, they swam in deeper water. But this shark was cruising shallows all dav. It’s the first Tiger Shark that’s been tracked doing anything like that. From my other experience, I’d thought that you would be safe from Tiger Sharks in very shallow water, but this one was right up against the reef.”
We need to run home. Chris calls, “O.K., shark, we’ll try to catch up with you tomorrow. Don’t eat any seals; you’ll get a bad reputation.”
WE’RE DETERMINED to get an earlier start today, and at a little before eight A.M. we’re again off East Island, sitting at anchor, listening for our sha
rk. The National Geographic crew will join us later—perhaps with some fresher bait—hoping to film us getting a second Tiger transmittered.
Brad seems in a sardonic mood. As soon as we anchor, he says, “This might be a long day.”
Chris answers, “A bad day at French Frigate Shoals beats a good day in Orange County. The sharks’ll be here by noon. Trust me.” Ten minutes later, he points. “There’s something—” He scrutinizes with both hands shading his eyes. “An Eagle Ray.”
The receiver is silent, save a faint static hiss. It detects no transmitters. Chris, scanning further with binoculars, says there’s something out on the flat. “Right where the really light green meets the slightly darker green. Moving fast, whatever it is—. Never mind; it’s a turtle.”
Brad states, “Tiger Sharks have had whole sea turtles in their stomachs. There really is a lot of food for them here at this time of the year. Maybe the sharks come long distances to be here now, like these other animals. But maybe they’re here all the time. So the questions are: Where do the sharks come from? Are they migrants or residents? How many are here? What effects might they have on endangered species and other wildlife?”
A short while later we notice two big turtles mating, attended by two smaller males. The male that is actually mating with the female is by far the largest. With binoculars we can really see how the claw on each front flipper lets him lock onto the female for a tight, sure grip, and how he uses his thick tail to help hold her posterior. He looks old and a bit weather-beaten, with several barnacles growing on his shell.
Picking up on Brad’s earlier comment, Chris says, “We analyzed data on Tiger Shark stomach contents collected over two decades of the shark-control program in the main Hawaiian Islands—from thousands of sharks. And compared to what people thought, they had a fairly low percentage of turtles in their stomachs. Over there they eat a lot of lobsters and eels off the bottom; plus needlefish, trumpetfish, and slow-moving things—pufferfish, those kind of things. In Australia they eat lots of sea snakes; in Florida they eat a lot of horseshoe crabs. They have a really varied diet, but it was quite a bit different than what people were saying. Fishermen were saying that they were eating lots of commercially important fish. But they weren’t.”
“The things we found about their movements, too,” Brad adds, “were different from what people had thought. Conventional wisdom was wrong again. In many places people see ‘the same shark’ day after day on the same beach. But when you tag them, you discover it’s not the same shark. Fishermen say, ‘Oh yeah—that shark—that’s the Landlord; we see him all the time.’ Then someone kills the Landlord and suddenly next week the Landlord is reincarnated. You realize when you start tagging that there are different sharks. And they’re not staying in one place. They’re huge animals, and they patrol large areas.”
Chris says that their movements don’t fit any regular pattern. Among the Tigers Brad and Chris have tracked, some left the capture site for weeks, then returned for a few days, then disappeared for a month, then visited for a couple of days. There was no regular routine. “Before we started our study, if there was a shark attack the state would go out and fish in that area to kill the culprit. So they’d go catch a shark, have it on the newspaper and TV and everything. Viewers could see a dead Tiger Shark and feel safer. The government could say, as a guardian of the people—especially tourists—‘We’re doing something about this!’ To some, it hardly matters whether they catch the culprit or not, just as long as it looks like they’re responding.”
Chris sums up: “Overall, Hawaii’s extensive control program did not affect the rate of shark attack. They long-lined around the islands for years, removing thousands of sharks. They spent hundreds of thousands of dollars to kill all of those sharks. Five months after the program ended, in an area where they killed thirty-three Tiger Sharks, there was an attack.”
The rate of shark attack remained about the same after the program as it had been before. “In Hawaii,” Chris continues, “about two people per year get bitten. But there have been only two confirmed fatal shark attacks there in the last forty-plus year: one in 1991, another in 1992. In 1991 there were four attacks, one fatal; a woman taking her daily swim off Maui was attacked by a shark and killed. That was the first fatal attack since 1958.
“After the woman got killed in ’91, there was another big call to kill sharks. The tourism industry didn’t want people thinking it’s dangerous in any way whatsoever to come to Hawaii. They wanted to avoid headlines, but the media went nuts anyway and—”
“Yeah, BLOOD BATH IN PARADISE: They’ve tasted human flesh. There’s no stopping ’em.”
Chris continues, “Some people pushed for slaughtering as many sharks as possible. People were saying there was a good chance of catching that specific shark. Of course, our tracking showed Tigers don’t stay in one place long at all. So the chances of catching a particular shark that attacks are very low.”
“People were saying it’s not safe to go into the water. Just like Jaws. ‘How many people have to die?’”
“Anyway,” says Chris, “the native Hawaiians were all up in arms about shark killing because they believe that sharks are guardian spirits. Plus, it was simply too expensive. So they did a limited control program.
“All of this raises two questions: How many sharks do you have to kill to make the water safe? And how safe does it have to be? It would make sense that the more sharks you kill, the lower the risk of shark attack. But apparently, that wasn’t true in Hawaii. And in Florida, where heavy fishing drove shark populations to their lowest levels ever, the rate of shark attack has increased—as the human population increases. They mirror each other. So it seems shark attack is more related to the number of people in the water than to the number of sharks. But even so, sharks actually kill very few people.”
Brad says, “There are constantly people in the water all over Hawaii, like fatted calves. If sharks wanted to eat people, they’d be biting more than just two per year. And like Chris. says, most of those are not fatal.”
Chris adds, “Meanwhile, there are forty drowning per year in the Hawaiian Islands. No one has suggested a wave-control program. People just figure big waves are part of the danger of being in the water. Well, instead of spending hundred of thousands of dollars killing sharks and probably not saving anybody, how about money for more lifeguards to control the number of drownings?”
“Do you realize how many people get killed by sharks every year, on average, worldwide?” asks Brad. “Ten. In the whole world.”
“Think about how many millions of people are in the water. The chances of getting attacked are very low. You can certainly increase your odds of attack if you’re out at night, or if you’re spearfishing and dragging bleeding fish,” adds Chris.
“I wish they reported the number of people killed by pigs. And by bee stings. Or crocodiles. Elephants—one year more people in Hawaii were killed by an elephant than by sharks; a circus elephant rampaged and killed three people,” Brad says.
Chris adds, “Hundreds of times more people get killed by dogs—” “Forget dogs; wanna talk automobiles?” Brad almost challenges.
“Cigarettes,” I offer, since we’re listing familiar things that kill more people than sharks.
“The common cold,” adds Brad authoritatively.
“Polluted water. Do you realize the thousands of children that die of diarrhea because of polluted water?” asks Chris.
I mention that I recently read that every year about a dozen children in America alone strangle to death after getting tangled in window-blind cords.
Chris says, “See—that’s more than the number of people killed by sharks worldwide.” Even in Florida, the place with the most attacks, sharks bite about one out of every million people that enter the water. “The odds of getting attacked are so low it’s a freak accident.”
“But psychologically,” Brad analyzes, “people just don’t like the thought of being bitten in half.”
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“Things that are actually much more dangerous get less attention,” Chris says.
“But with sharks,” Brad adds a bit indignantly, “there’s primordial fear.”
It seems that of all the many things that kill people, sharks probably kill fewer people than anything else. Chris says, “Compare it to the tolerance for other causes of death, like automobiles, like you said, or guns. I mean, the risks people are willing to take—”
“Gun control in the United States,” Brad picks up. “It’s something you can’t touch. Your right to bear arms. I read that something like thirty-one thousand people are killed annually by handguns in the United States. It’s a huge number. You could go out there, collect a bunch of guns, and actually change that death statistic. You could do something about it. But we won’t even take a step toward that. Compare it to, like, Britain, where they essentially don’t have handguns. There were, like, forty people killed in Britain by handguns last year.” Factoring in the difference in population, your chances of getting killed by a gun are 160 times higher in the United States than in Britain. “I don’t know how they murder people over there,” wonders Brad. “They must stab them or poison them, or beat them or something.”
We’re accustomed to taking prudent risks against far worse odds than getting in the water. But large predators evoke a response from a very ancient part of our brains. If we were accustomed to living in a place with a lot of predators, we might simply have a prudence and respect for them and a caution around them, like we do for automobile traffic. But we fear the unknown, things lurking in the dark or patrolling unseen below the water’s surface. And we fear the unfamiliar—like sharks. Many divers, scientists, and fishers who are familiar with sharks feel differently. They recognize them as potentially dangerous but understand that under normal conditions, they’re usually safe. They accept responsibility for their own risks, and know ways to avoid dangerous situations.
