where they spin 360 degrees underwater in a pirouette before they lunge, probably to line up their mouths precisely with a patch of krill. Other lightweight tags, launched with barbs that cling more deeply beneath the skin on the dorsal fin, have tracked the movement of Antarctic minke whales migrating over eight thousand miles of open ocean, from the Antarctic Peninsula to subtropical waters. These tags upload data directly to satellites whenever the whale surfaces, over the course of weeks to months, before eventually falling out. These tags are also especially useful for species that are rarely seen, such as beaked whales. Satellite-linked dive tags deployed on Cuvier’s beaked whales revealed, in a precise way, the astonishing extremes of their foraging dives for squid and fish—over 137.5 minutes of breath holding, 2,992 meters deep—data that set new dive records for a mammal. If the idea of holding your breath for over two hours doesn’t alarm you, imagine doing it while chasing your dinner to a depth of nearly two miles.
Tag data combined with tissue samples taken from biopsy darts tell us that these humpback whales feeding in the western Antarctic Peninsula are merely seasonal visitors for the austral summer. By early fall, they depart the icy bays, cross the great Circum-Antarctic Current that rings the seventh continent, and undertake various paths over thousands of miles to arrive at temperate latitudes. At Wilhelmina Bay the overwhelming majority of humpbacks return to the low latitudes of the Pacific coasts of Costa Rica and Panama to mate and give birth before returning to the Southern Ocean for the next austral summer to feed.
We eventually retrieved the tag, along with its data, and continued to Cuverville Island, on the other side of Wilhelmina Bay. As the Ortelius maneuvered out of the Gerlache and toward the island, I watched from the ship’s stern as we passed icebergs more massive than any I had yet seen. Their fragmented sides, a hundred feet high, were etched in luminous, milky blues and grays. They held light from sea to sky, glowing in unearthly ways, as if they could not have been formed on this planet. And of course they were mostly sheathed underwater, which was a bit of an ominous thought; the Ortelius kept a careful distance. But the incomprehensibility of something as overwhelming as an iceberg is belied by its transience: even the largest ones, platforms the size of cityscapes, will eventually shed their layers of ice, annealed over hundreds of thousands of years, and become part of the sea.
Scattered around the peninsula are several islands like the one we approached, islands that served as barely inhabitable platforms for whaling operations in the early and midtwentieth century. Today the only remnants of human civilization are occasional concrete pylons with bronze plaques identifying the area as an open-air heritage site, and leftover whale bones. After we hauled our rubber boat up on the rocks, I walked toward the spoil piles of green-stained and weathered whale bones, strewn like spare lumber at a construction site.
Reading whale bones is what I do, although sometimes I feel like the bones find me. I’ve spent so much time searching for them, cataloging them, and puzzling over them that my brain immediately recognizes even the slightest curve or weft of bone. Whale bones tend to be relatively large, so finding them is often largely a matter of making sure that you’re in the right neighborhood—it shouldn’t have been much of a surprise, especially on the grounds of an abandoned whaling station. On the island I mentally inventoried the first assemblage I encountered, as I dodged foot-tall gentoo penguins scrambling at my feet: ribs, parts of shoulder blades, arm bones, and fragments of crania. They clearly belonged to rorqual whales, about the size of humpbacks, or possibly even fin whales. Some of the more intact vertebrae were artfully balanced upright on the shoreline, probably posed by Antarctic tourists, passing through the peninsula by the thousands in the austral summer and looking for a perfect photograph.
If these bones belonged to humpback whales, it would not be surprising, given the abundance of this species out around Antarctica today. It’s likely that some of the whales that we tagged were descendants of these individuals, belonging to the same genetic lineage. But history tells us that if you turned back the clock a century, humpbacks probably wouldn’t have been the only ones here: blue and fin whales would have numbered in the hundreds, if not thousands; minke whales, beaked whales, and even Southern right whales would also have been part of the community. Ari has seen only one right whale out of the thousands of whales that he’s observed over fifteen years in the area. Southern right whales have barely recovered from two hundred years of whaling, and we know little about where they go besides their winter breeding grounds along protected coastlines of Australia, New Zealand, Patagonia, and South Africa.
It’s not just right whales that vanished. There’s no memory or record of just how many of any kind of whale there was in the Southern Ocean, in terms of their abundance, before twentieth-century whaling killed over two million in the Southern Hemisphere alone. However, as whale populations in this part of the world slowly recover from this devastation, we’re beginning to see what that past world might have looked like. On an expedition in 2009, Ari and his colleagues documented an extraordinary aggregation of over three hundred humpbacks in Wilhelmina Bay, the largest density of baleen whales ever recorded. “There is no external limit on these whales because there is just so much krill. They literally cannot eat enough before they need to leave,” Ari reflected. “That incredible resource base means that it’s just a matter of recovery time for whales—and I think what we saw in the bay that year was a glimpse of what their world was once like, before whaling.” On the whole, humpbacks have recovered to only about 70 percent of their prewhaling numbers in the Southern Ocean, although along the peninsula their population size has nearly returned to the best estimates of prewhaling levels at the start of the twentieth century.
I paused on a guano-free ledge to record a few observations about the bones’ weathering and their measurements in my field notes. To the southwest, the sky churned in a dark gray, portending wind and snow, and I felt a chill creep into my damp toes and fingertips. I pulled off my gloves and reached for a disposable hand warmer in my jacket pocket. Lodged in a mess of receipts and lozenge wrappers was a note my son had left me on the kitchen counter back home:
Im gona mis you
wen you go to
anaredica.
The night before I left my home in Maryland we traced the expedition route on a plastic globe. When he wanted to know how far away eight thousand miles was in inches, I didn’t tell him the answer that I wanted to, which was “Too far.” I reassured him that the passage was safe and that we would stay warm. “I’ll think about you when we drink hot cocoa,” I offered, dressing up my own concerns with a good smile.
As we pulled away from Cuverville Island to return to the Ortelius, the swirling clouds began to send down flurries, covering us in thick, wet snow. The boat bumped hard against the waves, and we saw humpbacks surfacing far off in the distance, the wind pushing their blows quickly behind them. The sight of those living, breathing, feeding whales in the same view as the island with beach-cast bones made me feel as though I could see the present and past simultaneously, each telling us facts that the other vantage could not. The bones on Cuverville Island and Ari’s tagging work in the Gerlache were each a unique window into the story of humpback whales in the Antarctic, though these views were terribly incomplete: the past represented by mere bones crumbling on remote shores, what we know today limited to a few hours’ or days’ worth of data collected by a hitchhiking recorder on whales’ backs.
Scientists tend to operate within intellectual silos because of the years of training and study that it takes to know about any single part of the world. But the best questions in science arise at the edges. Ari and I both want to know how, when, and why baleen whales evolved to become giants of the ocean—Ari wants to know more about their ecological dominance today, and I want to know what happened to them across geologic time. The answer to the basic question about the origin of whale gigantism requires pulling data and insights from multiple scientific disciplines, which is another way of saying that we need the perspectives of different kinds of science—and scientists—to untangle the monstrous challenges of the nearly inaccessible lives of whales. That’s why a paleontologist like me was
