• How the Resurgence of Whale Populations Impacts Our Ecosystem

    Christopher J. Preston on the History and Future of Whale Conservation

    The parking lot at the Sitka campus of the University of Alaska Southeast may be one of the most scenic parking lots in the nation. It sits on one side of Sitka Channel looking east across the water toward the town center. Fishing boats cruise slowly through the channel on the way to deliver their catch to local processers. Float planes and kayaks steer carefully around each other, while bald eagles and ravens wheel overhead in the salt-scented air.

    Across the water, St. Michael’s Russian Orthodox Cathedral pokes its oxidized copper dome above the jumbled roofs of Sitka’s high street. On the skyline, Mount Verstovia’s snow-streaked summit hints at the jagged beauty of Baranof Island beyond. The mesmerizing scene could have absorbed me for the whole day. But I had not come to Sitka to study landscape. I had come to study whales.

    At 10:00 a.m., Lauren Wild let me into the rectangular university building and took me to a small cluster of offices in its depths that house the marine scientists. When we entered her windowless workspace, her dog thumped its tail on the ground and turned a few happy circles before settling back under the desk to nap. The whiteboard behind Wild’s head mapped the tasks she needed to complete before teaching resumed in the fall.

    Wild is a professor of fisheries technology. “I study depredation,” she told me. This is the phenomenon of whales preying on the fishermen’s catch after they have it on their lines or in their nets. Depredation is a growing problem for fishermen all over Alaska.

    Nobody should be under the illusion that whales are out of danger.

    Wild was born and raised in Sitka. Her husband runs a salmon boat. Her brother longlines for black cod. A study-abroad semester in Madagascar sparked a passion in her for whales. On her return from the Indian Ocean, she joined a whale project in Glacier Bay National Park under the supervision of Jan Straley, a Sitka legend in whale research. Since the mid-2000s, Wild has been working on the conflict between sperm whales and fishermen.

    The problem of depredation first arose after a change in fishing practices in the region. In the mid-1990s, halibut and cod fishing moved to a quota system. Before then, fish were caught during a handful of frenzied twenty-four-hour derbies. The new quota system meant fishermen started spending much more time on the fishing grounds. The change coincided with a marked increase in sperm whale numbers across the North Pacific.

    The recovering whales used the newly extended season to learn how to pluck fish off the baited longline hooks used by fishermen. The valuable black cod—known as sablefish or butterfish due to their rich, silky texture—suddenly became much harder for fisherman to land. The whales were excellent thieves. The scene was set for fisherman-whale relations to go into freefall. But they didn’t. And the fact they didn’t is a clue that big changes in how we think about whales are afoot.


    Longlining is a lucrative fishery for small boat operators in Southeast Alaska. The longlines are laid on the ocean floor at the edge of the continental shelf at a depth of about six hundred meters. Hundreds of baited hooks connect to the line via a six-foot piece of nylon known as a “snood.” At each end of the longline is an anchor that keeps it attached to the ocean floor and a stretch of rope that hangs vertically from a buoy at the surface.

    After a six- to twelve-hour soak, the fishermen return to haul their set. They pull the buoy aboard with a boat hook, wrap the dripping line around a hydraulic winch, and start the long process of bringing the catch on board. The line gets coiled in tubs on the back deck. As the hydraulics whine, the boat pops in and out gear to keep it positioned to haul without getting tangled in the line. According to Wild, this jockeying of the engine makes a distinctive sound.

    “The acoustic cue is the propeller cavitation that these boats engage in when then are hauling gear up to the surface,” she told me. “That spinning of the propeller creates bubbles, and the cavitation is really loud.” The whales have learned to associate this sound with food. “We have clocked them over ten or twelve miles beelining when a boat starts hauling gear. They know what it means. It’s like a dinner bell.”

    Wild asked me to imagine it from the whale’s perspective. “You have like a sushi belt coming up from the bottom,” she said. “It’s really hard to resist.” Fisherman watch the whales feasting on their catch as the line comes to the surface. One Alaska fisherman reported a sperm whale laying alongside his boat while two more plucked fish from his line off the stern. He gave the whale a scratch behind the ears with a deck brush which the whale seemed to enjoy.

    Wild spent several seasons as a fisheries researcher on boats out of Sitka, Juneau, and Dutch Harbor. She gained a deep respect for the knowledge and skills of the fishermen. Most of them, in Wild’s experience, do not begrudge the whales. “They are happy to share the fish,” Wild said. “They just don’t want to share the fish they have caught.”

    Skippers told Wild about a range of different techniques employed by the whales. Some of them lunge haphazardly at whatever they see. Fish come up shredded, with teeth marks raked all over them. Others pull on the line to create tension so the fish pops off, as if understanding something about Newtonian physics. “An empty hook comes up, and you don’t know if the bait fell off or if a whale grabbed the fish,” Wild said.

    A third group engage in what the fishermen call “flossing.” When a whale sees a longline being pulled onboard a boat, they grab it in their mouth. “The whale lets the main line slide through their teeth and picks fish as they come by,” Wild said. The whales get the easy calories, and the fishermen have to rebait the hooks and burn precious fuel to fish somewhere else.

    Wild has experimented with fishermen and fisheries managers to find solutions. “We don’t want these whales to become like problem bears hanging out by the dumpsters,” Wild said. She took part in a study where they experimented with several methods of gentle dissuasion.

    They tried acoustic techniques. “We tested a playback device where we had recorded transient killer whale sounds,” Wild said. Sperm whales are known to treat killer whales as a threat. Fishermen have observed groups of sperm whales forming a rosette with their heads toward the center as they swim away from killer whales in a defensive pinwheel. If there is a calf in the group, they will put the calf at the center for protection.

    The recorded killer whale sounds did nothing. “They didn’t react at all,” Wild said. “I think we didn’t have the right setup and maybe the wrong pod of transients.”

    They tried white noise and different sound combinations to get on the whales’ nerves but without much luck. There are legal and ethical limits, Wild said, to how much you want to harass marine mammals with sound. They debated air bladders and flashing pieces of metal near the hooks to confuse the whales’ echolocation. They discussed whether you could send a small electrical charge through the line to shock them as they tried to bite the fish. Nothing seemed viable.

    Recently fishermen came up with something that appears to work. A longliner created a slinky pot—a collapsible, tubular pot made of fishing net stretched out by a coil of stiff wire. The pots get attached to the same longline that carries the snoods in traditional black cod fisheries. The crew cinch the pots closed when storing them on deck. When they are ready to set, they uncinch a pot, put in some bait, clip the pot to the longline, and hurl it overboard. The coiled wire opens the pot on its way to the ocean floor. Black cod swim inside to get the bait and end up trapped. They remain there until the fisherman returns to pull the gear. The whales are flummoxed.

    It’s too early to say whether every fisherman will make the switch to slinky pots. Some of them grumble about the investment in a new type of gear. But the difference between watching two-thirds of your fish going down the gullet of a sperm whale and landing everything you catch is significant.

    One fisherman told a trade magazine, “They’ve been a lifesaver for us.” Wild is unsure whether the slinky pots will make the conflict with whales go away entirely. “I used to say I would like to work myself out of a job,” she told me. She doubts this is going to happen any time soon. Sperm whale numbers are continuing to increase in the Pacific, and interactions with fishermen are becoming more frequent.

    Whales were once regarded as an exploitable resource that could be killed freely for profit. No more.

    As I heard the story unfold, my mind spun delighted pirouettes. It was a quirky example of a natural resource conflict that required collaboration, trial and error, and lots of patience to solve. It demonstrated the high intelligence of whales as well as their opportunism. It made demands on the creativity of fishermen.

    Yet from the beginning of our conversation, there was something else I could not get out of my mind. It was the fact Wild had to work on this problem at all. From a fisheries point of view, surging numbers of a highly intelligent and adaptable marine mammal creates a knotty problem. But from the point of view of whale conservation, the proliferation of whales is not exactly something to lament. In fact, it’s a pretty good problem to have. And Sitka, Alaska is not the only place confronting it.


    Risø is not the kind of coffee shop you expect to find two hundred miles north of the Arctic Circle. The baristas wear pressed white aprons and sport elegantly waxed moustaches. Jazz music softens the corners of a room that burbles with conversation and the clinking of silverware. Old friends and college students sit crowded around small tables, hunched over plates of eggs and Norwegian salmon. The weak November light paints everything amethyst outside.

    I arrived early to enjoy the atmosphere, knowing my meeting at Risø would likely be my only outing that day. The arctic winter encourages long hours cozied up at home. The Scandinavians are experts at hygge, the art of feeling warmth in simple things. The foam on my coffee drink had been scribed with a hovering ghost, a nod to the recent Halloween holiday. I took a sip and waited for the scientist who had promised to share with me the basics of whale recovery.

    Martin Biuw showed up wearing a woolen Norwegian sweater and a huge grin. His face was roughened by a graying stubble. He looked like a smaller version of Viggo Mortensen on a break from the movie set. Biuw is Swedish by birth. He and his wife share a two-story home a few miles out of town on Kaldfjord. Through a gap in the mountains, they can see the steep peaks of neighboring Ersfjord, the setting for thousands of postcards of Tromsø’s famous northern lights.

    Biuw is a senior scientist at the Institute of Marine Research in Tromsø. He spends weeks aboard heaving research vessels on remote oceans and long winter months crunching data from field sites around the world. His work on marine mammals has bounced him back and forth between the Arctic and Antarctic Oceans for more than a decade. It is a piece of sublime luck that also he happens to live on Kaldfjord.

    The scenic fjord, located ten miles outside Tromsø, caught the attention of Norway’s marine scientists a few years ago after scores of humpback and killer whales arrived to feed on gigantic schools of herring. The herring were not a total surprise. Biuw told me he had looked at church records spanning the twentieth century and found accounts of occasional superabundances of herring.

    “They mention these peaks of herring in Kaldfjord,” Biuw said, “but they don’t say anything about whales.” The humpbacks had been too depleted. The scarcity of whales had not always been the case. Biuw had talked with an elderly lady in Kaldfjord who said her grandparents told stories of large numbers of whales pursuing the herring into the fjord in the 1800s. “Probably, what we see now,” Biuw said, “is what we used to see before the whales were hunted.” Kvaløya, the island containing the fjord, translates into English as “whale island.”

    After whales started pouring into Kaldfjord in 2011, an instant whale watching industry sprang up to cash in on the surprise visitors. Europeans already flock to Tromsø each winter for a glimpse of the northern lights. If it is cloudy, which it often is, they entertain themselves with sled dog rides or by eating reindeer stew with herders in a gamme, a type of traditional Sami hut.

    These carefully curated experiences often end around a fire with some traditional Sami singing, known as joiking. For those determined to see the northern lights, Tesla EVs drive guests a hundred kilometers inland where the weather tends to be more cooperative. But now they had whales, and a fleet of boats quickly assembled to take advantage of the bonanza. It had been a century since Kaldfjord was awash in so many whales.

    Biuw didn’t hesitate when I asked him which whale species had made the most progress worldwide. “The humpbacks have made the most dramatic recovery,” he said. “But also the fin whales.” Fin whales are named for a sharp ridge that stretches between their dorsal fin and their tail. They are less well known to whale watchers than humpbacks because they commonly feed farther offshore.

    But fin whales are fast. “They go like a projectile through the water,” Biuw said. “It’s very dramatic.” When hunting, they turn on their side and lunge at fish or krill on the surface with their mouths partially open. Biuw told me of a recent expedition to the Antarctic to measure krill abundance. He was expecting a healthy humpback population, but he was astonished by the glut of whales he saw.

    “When we came close to the South Orkney Islands, we started seeing a huge number of birds, albatrosses, and all kinds of things, and we realized something dramatic was going on. Then we started seeing whale blows all over the place. There must have been fifty or sixty fin whales all feeding on this large school of krill. There were three or four blue whales mixed in. It was one of these feeding frenzies. Albatrosses everywhere. It was absolutely spectacular.” Passengers on one vessel recently sailing off the Antarctic Peninsula were treated to an experience even more remarkable than Biuw’s. They saw over a thousand of the typically solitary fin whales congregating in one, giant superpod.

    A whale’s size, charisma, and intelligence make it worthy of protection in its own right.

    Despite a few local populations remaining vulnerable, both fins and humpbacks across northern and southern oceans have rebounded. Some of the increases involve breathtaking numbers. Humpbacks in the western Indian Ocean have grown from around six hundred to 36,000. Populations off both east and west coasts of Australia passed 50 percent of their preexploitation levels in 2015, with growth rates of more than ten percent a year.

    The number of humpbacks in Glacier Bay, Alaska, went from forty-one in 1985 to 239 in 2013. Worldwide, the species may be completely recovered by the end of the decade. Southern Ocean right whales had recovered from a low of 300 in the 1920s to over 15,000 today, with some populations growing at seven percent a year. Bowhead whales in the Bering, Chukchi, and Beaufort seas have tripled and are close to pre-exploitation levels.

    All of these bits of good news should be put in perspective. Many whale populations still struggle. North Atlantic and Pacific right whales stand on the brink and may be headed for extinction. Bowhead whales around Svalbard and the Okhotsk Sea number in the low hundreds. Blue whales, the ocean’s mightiest whale, remain critically endangered in Antarctica, where their population is only one percent of historic levels. Gray whales have been dying all along the Pacific Coast in worrying numbers.

    Threats to whales from pollution, fishing gear, ship strikes, and climate change are increasing every year. The noise caused by boat traffic and wind turbine installation is beating down the edges of the whale’s acoustic world. In 2020, more than 350 experts from around the world signed an open letter to global leaders warning that half of cetacean species are still under threat. Nobody should be under the illusion that whales are out of danger.

    Yet the whales that are doing well are important. Not only do they show that not killing an endangered animal can be a remarkably effective conservation strategy; they also open doors to new ways of thinking about wildlife. Whales were once regarded as an exploitable resource that could be killed freely for profit. No more. Millions of people now value them as a watchable treasure worth protecting.

    Many whale watchers also value them inherently for what they are in themselves, whether or not they ever get the chance to see one. A whale’s size, charisma, and intelligence make it worthy of protection in its own right. This is clearly an ethical advance, a small sign of moral maturation in our species.

    I was, however, about to learn an even more interesting ethical perspective on whales, something deeper than just giving them a higher rank in value. To understand what these lessons were, I needed to take a closer look at the resurgence of humpback whales in the North Pacific. I also needed a different kind of scientist to unlock that intriguing ethical door.


    Adapted from Tenacious Beasts: Wildlife Recoveries That Change How We Think about Animals by Christopher J. Preston. Copyright © 2023. Reprinted with permission from MIT Press.

    Christopher J. Preston
    Christopher J. Preston
    Christopher J. Preston’s essays have appeared in The Atlantic, Smithsonian, Aeon, and on the BBC website. He teaches environmental philosophy at the University of Montana and lives in Missoula, MT.

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