I sat transfixed by a sea littered with a million fragments of ice, all rising and falling in time with the slow roll of the waves. We had spent the morning looking for humpback whales in Wilhelmina Bay, threading our rubber boat between gargantuan icebergs that were tall and sharp, like overturned cathedrals. Now we stopped, cut the engine, and listened in the utter stillness for the lush, sonorous breath of an eighty-thousand-pound whale coming to the water’s surface. That sound would be our cue to close in. We had come to the end of the Earth to place a removable tag on the back of one of these massive, oceangoing mammals, but we took nothing for granted in Antarctica. As we sat waiting on the small open boat, I came to feel more and more vulnerable, a speck floating in a sea of shattered ice. “Don’t fall in,” my longtime collaborator and friend Ari Friedlaender deadpanned.
I struggled to remember how long we had been away from the Ortelius, our much larger oceanic vessel with its ice-hardened steel hull. In every direction, we were enclosed by a landscape of nunataks, jagged spires of rock that pierced the creamy tops of surrounding glaciers. Where the glaciers met the sea, they ended in sheer, icy cliffs towering over the bay. Without a human structure for scale, these landforms seemed both near and far at the same time. This otherworldly scene of ice, water, rock, and light warped my sight lines, bending my sense of distance and the passage of time.
If you hold your fist with your left thumb out, your thumb is the western Antarctic Peninsula; your fist, the Antarctic continent’s outline. The Gerlache Strait is part of a long stretch of inner passageway along the outer side of Antarctica’s left thumb, and Wilhelmina Bay cuts a rough cul-de-sac off the Gerlache. The Gerlache is a hot spot for whales, seals, penguins, and other seabirds, and Wilhelmina Bay is the bull’s-eye. All come here to hunt for krill, small crustaceans that form the centerpiece of Antarctic ocean food webs. Consider your hand again: individual krill are about the length of your thumb, but whales pursue them because they explode into great aggregations, or swarms, during the Antarctic summer. With the right mixture of sunlight and nutrient-rich water, dense clouds of krill form a sort of superorganism that can stretch for miles and concentrate in hundreds of individuals per cubic foot. By some measures, there is more biomass of krill than of any other animal on the planet. Calorie-rich swarms of them lurked somewhere, not far, just under our boat.
Where there are krill in sufficient quantities, there will be whales, but the fundamental problem with studying whales is that we almost never see them, except when they come to the surface to breathe or when we dive, in our own limited fashion, in search of them. Whales are inherently enigmatic creatures because the parameters of their lives defy many of our tools to measure them: they travel over spans of whole oceans, dive to depths where light does not reach, and live for human lifetimes—and even longer.
In Wilhelmina Bay our goal was to attach a sleek plastic tag to the back of a whale to record audio, video, depth, changes in the whale’s speed, and even pitch, yaw, and roll. Our tags would provide crucial context for how humpbacks interact with their environment by relaying, in a time-stamped way, how they feed on krill. Ari and his colleagues have tagged and tracked whales along the Antarctic Peninsula for nearly two decades, charting their movements against the backdrop of changes in krill-patch density, water temperature, daylight, and other variables. As climate change warms the poles faster than the rest of the planet, every year counts.
I sat on the gunnel of the boat while Ari scanned from the bow. We were several days into a multiweek expedition with high hopes to tag as many humpbacks as possible—ideally, a pod feeding together—but thus far we had been skunked. Ari stood rigid like a figurehead, holding a twenty-foot-long carbon-fiber pole in folded arms. The pole flexed in synchrony with the swell, the teardrop-shaped tag bobbing at one end. I watched clouds shift slowly overhead, mirroring the dappled quicksilver of the water, and wondered whether any other place on Earth could feel as alien as Antarctica. Then a loud gurgle interrupted my daydreaming, followed by a trumpeting blast of water vapor bursting from flaring, paired nostrils. A whale’s blow.
We knew to expect more plumes of water immediately thereafter. A pod of whales synchronize when they surface to breathe—sometimes nearly simultaneously or split seconds apart. They usually breathe a few times in a row, in quick succession, before resubmerging—unless they’re asleep or truly exhausted, whales tend to act like surfacing is a nuisance and they’d rather be deep underwater. Their tight coordination in breathing likely has a lot to do with maximizing time spent below the surface engaged in the cooperative tasks of finding food and avoiding predators. Some species travel or hunt in pods that are tightly knit family genealogies, while others, such as the humpbacks before us, form short-lived associations, seemingly a matter of happenstance.
“Oh, that’s right,” Ari called out. The vapor from the blow lingered in the cold air. Ari pointed to a small patch of water a dozen yards from the boat, perfectly calm against the waves at the surface. This patch, called a flukeprint, betrayed the whale’s movement, unseen deep below our tiny boat. The single flukeprint bloomed into several, each the size of our boat, rising up from the depths, whirling and spreading into the smooth geometry of a lily pad. We were right. “He’s got buddies,” Ari said. Without the aid of an echo sounder—which would also tip off the whales about our location—we used the ephemeral patterns on the surface to read their path.
We started up the engine, throttling ahead slightly to a spot beyond the last flukeprint. Within seconds, right on cue, a pair of enormous nostrils bubbled at the surface, releasing a thundering tone and then a spray that carried past us as we kept up with the whale. A dorsal fin surfaced, and a second and third blow exploded nearby. “Pull up behind this last one. We have about three more breaths until they go down,” Ari shouted.
We trailed the laggard of the group, maneuvering the boat into position. Ari lowered himself across the bow and held the pole against his torso, extending the tip with the tag just ahead of the dorsal fin as we motored close to the behemoths moving yards away. Then, in a decisive motion, Ari launched the tip of the pole toward the whale’s back, where the tag’s suction cups hit the skin with a satisfying thwack. The whale rolled beneath the surface as we pulled back to pause and wait for it to return. We spotted its sleek, shiny back as it arose again, marked with a neon tag, and we cheered. The whale took one last breath before it raised its monstrously wide tail flukes out of the water and slipped down into emerald darkness with the others. Ari radioed back to the Ortelius. “Taaaaag on,” he said with a hint of swagger as he grinned at me.
Tag on
The whole rodeo of tagging is a bit like sticking a smartphone on the back of a whale, complete with the logistics of getting close enough to a forty-ton mammal in the first place. Just as your smartphone can record movies, track where you go, and automatically rotate images, the same technology—miniaturized and cheap, combining video, GPS, and accelerometers all in one device—has fueled a revolution in understanding how animals move throughout their world. Scientists call this new way of recording