Deep

Freediving, Renegade Science, and What the Ocean Tells Us About Ourselves

James Nestor

• Éditeur: Mariner Books
• Année: 2014
• ISBN:
  9780547985633
• Sujet: Ciencias biológicas
• Sous-sujet: Ecosistemas y Hábitats

From the bestselling author of Breath, a "fascinating, informative, exhilarating" voyage from the ocean's surface to its darkest trenches ( Wall Street Journal)

New York Times Book Review Editors' Choice•An Amazon Best Science Book of 2014• Scientific American Recommended Read

Fascinatedby the sport of freediving—in which competitors descendgreat depths on a single breath—James Nestor embeds with a gang of oceangoing extreme athletes and renegade researchers. He finds whales that communicate with other whales hundreds of miles away, sharks that swim in unerringly straight lines through pitch-black waters, and other strange phenomena. Most illuminating of all, he learns that these abilities are reflected in our own remarkable, and often hidden, potential—including echolocation, directional sense, and the profound bodily changes humans undergo when underwater. Along the way, Nestor unlocks his own freediving skills as he communes with the pioneers who are expanding our definition of what is possible in the natural world, and in ourselves.

"A journey well worth taking." —David Epstein, New York Times Book Review

"Nestor pulls us below the surface into a world far beyond imagining and opens our eyes to these unseen places." — Dallas Morning News

"This is popular science writing at its best." — Christian Science Monitor

−1,000

“IT WAS LIKE A NEAR-DEATH experience. Like being transported to some other place, some other plane,” says Fabrice Schnöller.

Schnöller and I are sitting together at Planet Nature, a health-food restaurant he owns with his wife in downtown Saint-Denis, Réunion. Schnöller uses the second-floor seating area as his office, but it looks more like a storage room. USB cables and electrical cords cover a desk like ivy. Stacks of scientific papers teeter on the tables. Rows of dog-eared academic books cram corner shelves.

It’s a few months after my meeting with the ama, and, against the complaints of my lower back, I’ve returned to Réunion. I’ve been lured here by Schnöller, who e-mailed me a few weeks ago and said he was on the cusp of a “big discovery.” It had something to do with whale and dolphin clicks, but he was short on specifics. He told me he’d invited a team of scientists, researchers, and freedivers from all over the world to come to Réunion for a weeklong conference to discuss it.

“You should join the team,” he said. I accepted and flew thirty-two hours to reconnect with him and his crew. My plan was to stay ten days.

Now, a few hours before the conference convenes, Schnöller sits me down and recounts how he sold his business and decided to dedicate his life to studying dolphin and whale click communication.

“It started while I was sailing to Mauritius, about five years ago,” he says, taking a sip of Dodo beer. “That’s when everything changed.”

SCHNÖLLER WAS CAPTAINING a sixty-foot sloop called the Anna­belle that his friend Luke had just bought from Paloma Picasso, a daughter of Pablo Picasso (an original Picasso still hung in the hull). A few hours into the thirty-six-hour trip, Luke and the six other crew members were below deck incapacitated by seasickness. The onboard chores fell to Schnöller.

Schnöller didn’t mind. He enjoyed captaining the Annabelle, mostly because he liked being alone at sea, especially in the dark. Around eleven on the first night, he leaned back in the captain’s chair and stared out across a gaping sky, glistening with stars. In his left hand, he held a thermos filled with coffee; with his right, he turned the oversize wheel of the ship to the northeast. He listened to the syncopated thump of waves crashing on the prow, and he imagined that the sound was coming from some large hand reaching up and tapping out a pattern on the ship’s bottom, like fingers on a bongo drum. Through his headphones, the spiraling bass line of the Doors’ classic “Riders on the Storm” faded in; the sound of canned winds and rain from the song mixed with the real wind and splatter of spindrift that blew salty water on his face and hair. Schnöller smiled, sailed on, and watched as the blackness of night drained out of the sky like water from a dirty sink, leaving only clear blue and orange in its wake. It was morning again.

By 10:00 a.m., the winds had calmed and swells subsided. The crew members slowly emerged from the cabin with puffy eyes and swollen faces, exhausted. Captain Luke apologized for leaving Schnöller on watch all night. Schnöller nodded, took another sip of coffee, and swallowed the last bite of the sandwich Luke had packed for himself to eat later. He kept his eyes on the horizon. Luke noticed a column of mist at the side of the boat—it looked as if a grenade had detonated in the water. Then another little bomb went off, and another. Schnöller had heard from other sailors that there were whales in this stretch of the Indian Ocean. Seeing them at a distance was common, but having your ship surrounded by them was practically unheard of. Schnöller felt a strong urge to jump in and swim with them.

He went below to grab his mask, fins, snorkel, and a waterproof camera. Luke met him at the back of the boat and begged him to stay on deck. Another crew member, Jean-Marc, joined Schnöller on the transom, and they both jumped in the water.

The ocean is usually silent, but the waters here were thundering with an incessant click-click-click, as if a thousand stove lighters were being triggered over and over again. Schnöller figured the noise must be coming from some mechanism on the ship. He swam farther away from the boat, but the clicking only got louder. He’d never heard a sound like this before and had no idea where it was coming from. Then he looked down.

A pod of whales, their bodies oriented vertically, like obelisks, surrounded him on all sides and stared up with wide eyes. They swam toward the surface, clicking louder and louder as they approached. They gathered around Schnöller and rubbed against him, face to face. Schnöller could feel the clicks penetrating his flesh and vibrating through his bones, his chest cavity.

“I felt like I was contacting ET, you know, like this was communication from another planet,” says Schnöller. He and Jean-Marie spent two hours swimming with the whales that day. He’d known nothing about whales before the encounter. Afterward, they became his obsession.

When Schnöller got home to Réunion, he Googled images of whales and compared the photographs he’d taken with those he found online. Sperm whales are the largest of the toothed whales, and, according to historical accounts, the most ferocious whale predators. Historical images that Schnöller found depicted them killing humans, crushing boats, gorging on giant squids. But in his brief experience with them, Schnöller saw the whales to be gentle, curious, and intelligent, making him wonder how accurate those old images were. With their eight-inch teeth, the whales could easily have killed him. But instead they approached in peace and welcomed him into their pod. Schnöller wanted to understand how history and reality could be so far apart. He looked around for the latest sperm whale–behavior studies. But there weren’t any.

“I assumed the military, thousands of scientists around the world, were conducting studies on these animals,” he says. “I found nothing—no research, no videos, no photographs.”

Schnöller realized the only way he could get his wife, the other crew members on the boat, or anyone else to understand the experience he had was to begin his own research program. Six months after the sperm whale encounter, he sold his lumber supply store and started the nonprofit DareWin. He enrolled in biology courses at the University of Réunion. He learned that dolphins, beluga whales, orcas, and other cetaceans also use the distinct clicking sounds he’d heard and felt swimming with sperm whales.

Sperm whales rarely visit Réunion’s coast, but bottle-nosed dolphins, which can dive down to a thousand feet, are common. Schnöller focused on recording interactions between dolphins and analyzing their vocalizations, which include clicks, burst pulses, and whistles.

Over the past five years, Schnöller and his small crew of volunteers recorded more than a hundred hours of wild dolphin behavior—the largest collection of its kind in the world.

SCHNÖLLER GETS UP AND LEADS me to his desk. Behind a lump of papers is an oversize computer monitor with a spectrogram readout—a visual representation of an audio signal—showing some dolphin clicks and other vocalizations he had recorded months earlier. He starts a track, which he says contains rapid click patterns called burst pulses. The speakers blast what sounds like party whistles and machine-gun fire. “All those noises, they are all coming from one dolphin,” he says. “One dolphin.”

Dolphins and other cetaceans use these clicking sounds as part of a sophisticated form of sonar called echolocation. They’re similar to the clicks sperm whales used to shake Schnöller’s body years ago, only weaker.

To understand cetacean echolocation, Schnöller says, you first need to understand sonar.

A simple sonar system, consisting of one speaker and one hydrophone (an underwater microphone), works by first sending out a pulse sound, or ping. That ping travels through water until it hits something, then echoes back. The hydrophone records the echo, and a processor calculates how long it took for the echo of the ping to return. This system can provide information on how far away an object is and the direction it is moving, but nothing more.

A more complex sonar system includes dozens of hydrophones distributed over a wide area. When a ping is sent out, the echo that returns reaches each of these hydrophones at a slightly different time. With this extra information, the sonar system can determine not only the distance of an object, but its shape and depth. A rough picture emerges.

Dolphins and some whales have the equivalent of thousands, even tens of thousands, of echo-collecting hydrophones built into their heads. When a cetacean sends out a click (its version of a sonar ping), it receives the echo information with a fatty sac located beneath the lower jaw. Unlike ears, which provide only two directional sources to gather information, this fatty sac provides the cetacean with thousands of data points. The animal can process these to gauge the distance, shape, depth, interior, and exterior of the objects and creatures around it.

Dolphins can detect the shape, position, and size of larger objects from up to six miles away. Their echolocation is so powerful and sensitive that it can penetrate over a foot deep into sand; it can even “see” beneath skin. Dolphins can peer into the lungs, stomachs, and brains of the animals around them. With all this information, scientists believe dolphins can create the equivalent of an HD-quality rendering of objects nearby—not only where these objects are, but how they look from the inside out. In essence, dolphins and other cetaceans have x-ray vision.

Echolocation isn’t just a curiosity; it’s essential for a cetacean’s survival. Ninety percent of the ocean is cloaked in permanent blackness, and even those areas near the surface are black at night. To adapt to this dim-lit environment, some animals evolved to have super-sensitive eyes; others create their own light with bioluminescence; rays and sharks use electro- and magnetoreception. Cetaceans evolved to have remarkable powers of echolocation.

THIS “SENSE” IS NOT RESTRICTED to the ocean. Bats have used echolocation for fifty million years to thrive in complete darkness. Humans have echolocated for hundreds, perhaps thousands of years.

French philosopher Denis Diderot noted instances of “blind sight” in the mid-1700s. Almost a century later, in the 1820s, a blind English adventurer named James Holman traveled around the world using a self-taught form of echolocation. The public was skeptical about Holman and other human echolocators. Most people believed they had partial vision or perhaps were using something called facial vision, the sensation of pressure increasing on one’s face as one moves closer to an object. In 1941, a Cornell University psychologist named Karl Dallenbach tested for it.

He gathered a group of blind subjects and had them walk toward a wall. When they believed that they could perceive the wall, they were told to raise their left arms; when they thought they were about to collide with the wall, they were to raise their right arms. The blind subjects succeeded in perceiving the wall from dozens of feet away; they stopped mere inches before walking into it. Dallenbach then gathered a group of sighted subjects, blindfolded them, and repeated the experiment. The sighted people perceived the wall almost as accurately as the blind ones.

Next, Dallenbach had the subjects walk on a carpeted path that an assistant blocked with a board at random intervals. After thirty trials, the blindfolded, sighted subjects could locate the board just as reliably as the blind subjects. Dallenbach then tested for facial vision by putting felt hoods over subjects’ heads, which would minimize any pressure sensations they could pick up from their surroundings. The hooded group easily perceived the board and wall as accurately as they had without the hoods. Dallenbach concluded, correctly, that humans did not use facial vision; we too had a sixth sense of echolocation.

A FEW WEEKS AFTER SCHNÖLLER introduced me to the otherworldly concept of echolocation, I’m walking down a street in suburban Los Angeles with Brian Bushway, one of the world’s most gifted human echolocators. As we stroll toward a restaurant he’s chosen for lunch, Bushway emits a sharp, short click from his mouth, then points out an empty driveway on our right, a van parked to our left, and rows of overgrown bushes on an upcoming corner. He clicks in the other direction and mentions that the house we just passed is small and covered in plaster, while the one across the street has large bay windows. The lawn in front of the apartment complex just ahead is in sore need of gardening. Bushway gets to the end of the sidewalk, pauses a moment, then leads me past two parked cars and up a curb to the sidewalk on the other side of the street. We take a right, he clicks again, and then he walks me through a crowded parking lot. He tells me the Cuban restaurant we’re going to is up this way. I follow him through the entrance and into a crowded dining room. A server walks us to a corner table and hands us menus. Bushway puts the menu down, without looking, and tells me to order for him. He can’t read the menu; he can’t even see it. He’s blind.

I learn about Bushway through YouTube videos. I watched him dashing along a dirt trail on a mountain bike, nimbly dodging branches, bushes, and boulders, and then riding down a steep flight of stairs. Next, he was jogging across a river and through a thirty-foot-wide mud pit. Another video showed him walking through a park, approaching a tree, and climbing it.

Bushway, who has a muscular frame and a frizzy mop of hair, tells me he began losing his vision at fourteen. One day, he couldn’t make out writing on a school chalkboard. A few weeks later, while playing hockey, he couldn’t find the puck. He started having trouble recognizing his friends. A new set of contact lenses didn’t help. When he woke up one morning and saw that everything in his field of vision was bright white, his mother rushed him to the hospital. A doctor dilated Bushway’s pupils, then turned off the light to conduct a routine check.

“The lights never came back on again,” says Bushway, taking a napkin from the table and placing it on his lap. “After that, I remember walking out of the office with my mom and asking, ‘Is the sun out?’”

The sun was out, but for the first time in his life, Bushway couldn’t see it. He would never see anything again.

Bushway suffered from optic nerve atrophy, a rare disease that destroyed the optic nerves in both eyes. After he got home from the doctor’s office, he spent the next several months feeling helpless. Doctors recommended doing a biopsy of his optic nerve so they could test whether the damage was genetic. Surgeons shaved half of his head, cut out a section of his skull, moved his brain aside, and clipped out part of his optic nerve. After the surgery, scar tissue formed on his brain. He started having seizures. Doctors put him on antiseizure medication, which gave him extreme vertigo and constant shakes. “I felt uncomfortable moving,” he says. “I just sat on the couch and listened to talk radio and books on tape.” The highlight of his day was going with his mother to a drive-through restaurant, picking up food, coming home, and eating it.

Bushway returned to school a few months after he lost his sight. In the past, he had prized his independence and lived an active lifestyle. Now, an adult needed to guide him around campus. He could no longer play sports, walk by himself, or relate to his friends. He felt like an outcast, totally alone. He dreaded the idea of living the rest of his life this way.

Weeks later, while standing in the courtyard of his school, he suddenly sensed something in front of him. It was a pillar. He noticed several more pillars next to it. “I wasn’t touching them,” he says. “I was five feet away, but I swore I could see them. I could count them—it was like a sixth sense; it’s even a magic power.”

Bushway was soon back to riding his skateboard, shooting hoops, and roller-blading. He joined a mountain-biking team and bombed down local trails. His vision hadn’t returned; the optic nerve damage was irreversible. Instead, another sense within him had suddenly turned on that allowed him to “see” through his blindness. With this sense, Bushway could point out a car in a parking lot a hundred yards away, tell you the width of a tree trunk from across a sidewalk, and distinguish a Rubik’s Cube and a tennis ball from across a dining-room table.

He honed these skills with the help of a blind activist named Daniel Kish, whom he’d met at a lunch for blind students a few weeks after first sensing the pillars at school. Kish, who had lost his own sight at the age of one, ran a nonprofit organization called World Access for the Blind. The program taught blind people how to use an echolocation system that Kish had developed called FlashSonar.

FlashSonar isn’t a device; all the tools required to use it exist inside the human body. And the “magic power” that allowed Bushway to first see the columns in the courtyard at school wasn’t magic at all, Kish explained. It was the same echolocation sense that dolphins and whales used to navigate through dark ocean depths for the past fifty million years. Humans could also “see” in the dark, he said. Most of us had just forgotten how.

BACK AT THE CUBAN RESTAURANT, I watch Bushway emit a quick, crisp click from his mouth, pause a second, and then reach across our table to grab a water glass. We pay the bill and Bushway clicks again as we get up from our table. He’s still clicking when he leads me out of the crowded restaurant, through a parking lot, and across bustling sidewalks. At the footpath to his apartment building, he stops, tells me to watch my step, and then takes me through his front door.

It’s time for my first lesson in FlashSonar. He asks me to stand arm to arm with him in the middle of his living room. He lifts his tongue to the roof of his mouth and slaps it down just behind his bottom teeth, releasing a click. He listens for the echo of this click to determine the shape and distance of things around him.

For instance, a wall three feet from him will reflect an echo faster than one further away. Objects sound different too, depending on their structure and materials. “If something looks soft,” Bushway tells me, “it will sound soft.” A wooden wall, for instance, absorbs more sound, so the echo will be more muted than that of a glass door. Bushway perceive...