In bluefin tuna, fisheries science is never neat

Could the future of bluefin tuna really be "safe and secure," as one biologist put it?

Published August 2, 2023 3:30PM (EDT)

Atlantic bluefin tuna (Thunnus thynnus) trapped in a seine fishing net. (Getty Images/Antonio Busiello)
Atlantic bluefin tuna (Thunnus thynnus) trapped in a seine fishing net. (Getty Images/Antonio Busiello)

This article originally appeared on Undark.

Spend enough time in the world of fisheries science, and you're likely to hear an adage, coined by a researcher named John Shepherd, that neatly encapsulates the field's uncertainty. Counting fish, the saying goes, is not unlike counting trees — if the trees constantly moved around the forest, and also you had to somehow tally them blindfolded. The point is clear: Few natural resources so confound measurement, let alone management, as fish.

Fisheries biology is an inherently challenging science that's made even more difficult by its tense relationship with commercial fishing. The on-board observers who collect critical data sometimes face harassment and even, allegedly, murder by the crews they monitor. Illegal fishing runs rampant, making it hard to know how many fish are being pulled from the sea. And catch limits are set by councils beholden to the very industry they're supposed to regulate. Add it up, and it's hard not to conclude that, as Karen Pinchin puts it in her riveting debut book, "Kings of Their Own Ocean: Tuna, Obsession, and the Future of Our Seas," fisheries science is "an impossible, thankless job with no easy answers."

Pinchin's eponymous kings are Atlantic bluefin tuna, marine predators that can weigh well over a thousand pounds — "imagine a grand piano shaped like a nuclear weapon," as Pinchin puts it. Bluefin are extraordinary organisms: warm-blooded, keen-eyed, coated in pigment-producing cells that flash a rainbow of colors when the fish are hauled onto a boat.

Pinchin excels at evoking her piscine subjects, whose sickle-shaped tails beat nearly as fast as a hummingbird's wing. "To stand beside a just-landed giant bluefin, still slick from salt water, feels akin to standing beside a natural marvel like Niagara Falls or an erupting volcano," writes Pinchin, a Nova Scotia-based science journalist. "There's beauty, but also danger."

Her book isn't just an ode to bluefin — it's about humankind's obsession with them, a fixation as old as our species. Early hominids harvested tuna that orcas chased onto European beaches; Greeks and Phoenicians depicted them on currency; Spaniards funneled them into labyrinthine traps near the Strait of Gibraltar; and 20th-century sportfishermen hooked them off North America's eastern seaboard. By the 1980s, tuna fisheries on both sides of the Atlantic had come to be dominated by Japanese buyers, who prized the rich belly meat known as toro. Today bluefin comprise just 1 percent of the world's tuna catch, but two-thirds of its total value.

Pinchin's own obsession began in 2019, the year she learned of the late Al Anderson, the curmudgeonly captain of a charter fishing boat called the Prowler. In the 1960s, Anderson, a conservation-minded angler who also taught high school biology, began jabbing plastic tags — emblazoned with dates, GPS coordinates, and other data — into tuna his clients caught and released off the Rhode Island coast. Ultimately Anderson would mark more than 60,000 fish, likely among the largest citizen-science efforts in fisheries history.

A young female bluefin that Anderson tagged in 2004, for example, ultimately turned up in a Portuguese net in 2018 — an astonishing testament to her species' nomadic nature. Scientists dubbed the fish Amelia, as in Earhart, another traveler renowned for a trans-Atlantic journey.

Amelia's epic migration was no mere curiosity: As Pinchin explains, it vividly demonstrated the folly of conventional tuna management. Historically, biologists believed that the Atlantic Ocean's bluefin were divided into two populations that rarely mingled: one that spawned in the Mediterranean, another that spawned in the Gulf of Mexico. Under this "two-stock model," codified by a coalition of tuna-harvesting nations in 1981, fish caught off Europe and Africa were deemed "eastern," and tuna caught near North America were considered "western."

With bluefin split in half, two distinct approaches to their governance emerged. Whereas the U.S. and Canada restricted catches to prevent overfishing, European harvests "remained a free-for-all with no quotas on how many fish could be caught and killed." The two-stock theory, Pinchin posits, thus "allowed humans to run roughshod over one of the world's most contested species for decades."

"Kings of Their Own Ocean" serves, in a sense, as an extended debunking of this catastrophic paradigm. As early as the 1970s, fish tagged by Anderson and other North American anglers turned up in Europe, demonstrating that the supposedly isolated pools of fish often mixed. Yet the two-stock model persisted, in part because managers found it "frustratingly inconvenient" to incorporate such complexity into their equations, Pinchin writes. Although the decision to cleave bluefin into two populations was motivated primarily by what she calls "political expedience," fisheries managers came to defend it as "scientific truth" even in the face of conflicting data — a concession to industry, masquerading as empiricism.

And what was the managerial authority that clung to the two-stock theory? That would be the International Commission for the Conservation of Atlantic Tunas, a regulatory body so dominated by commercial interests, writes Pinchin, that environmentalists once joked that its acronym, ICCAT, should stand for the "International Conspiracy to Catch All Tunas."

The dig wasn't unwarranted: In 2008, for example, ICCAT's scientific committee proposed a total allowable catch of about 11,000 tons — only to see its member nations set the quota three times higher. Through this and many other examples, Pinchin ably proves one of her book's primary theses: that "science itself, the tool and technique through which we grasp for certainty in an uncertain world, has little to do with who, or what, wins or loses."

With admirable thoroughness and clarity, Pinchin guides us through the human ecosystem that surrounds bluefin tuna — the scientists, the activists, the fishermen, the bureaucrats. Each figure seems to have a different interpretation of tuna research, a further suggestion that fisheries management is a social science as well as a biological one. Witness the conflict between two of her book's central figures: Molly Lutcavage, a marine scientist who collaborates with commercial fishermen, and Carl Safina, a conservationist and author more apt to fight them.

Pinchin spends several pages explicating their personal animus, which ostensibly stems from an arcane debate over the location of bluefin spawning grounds but seems really to be about how scientists should position themselves vis-a-vis industry. To Lutcavage's mind, Safina and his ilk are alarmists who fail to recognize that fishermen have a "vested interest" in preserving the tuna on which they depend. Although Pinchin doesn't push back against this argument, it seems facile: If it were true, overfishing would never occur, but of course it does.

In some ways, however, Pinchin's account ultimately vindicates Lutcavage — for, despite the historic mismanagement she depicts, she paints a surprisingly rosy picture of bluefin's future. According to one biologist, new management paradigms, better data, and improved collegiality between ICCAT's members have left bluefin "safe and secure." That claim may seem hyperbolic — climate change, ocean acidification, and other epochal threats mean that no marine life is secure, aside perhaps from jellyfish and a few other organisms — yet it's heartening to know that bluefin are no longer entirely synonymous with the corruption of science.

And what of Al Anderson, the Rhode Island fisherman whose myopic devotion to his quarry recalls another famous New England sea captain? Anderson's tuna-tracking project doesn't prove quite as pivotal as a reader might hope: Were "Kings of Their Own Ocean" a Hollywood movie, it would culminate with the old salt slapping down one of his tags at an ICCAT meeting to disprove the two-stock theory and reform tuna management once and for all.

Instead, the bluefin's more hopeful future appears to be the product of many separate lines of evidence — revised catch estimates, satellite tracking data, new mathematical models — gradually accumulating to advance humanity's knowledge. But perhaps that's appropriate. If Pinchin's book makes one thing clear, it's that fisheries science is never neat.



Ben Goldfarb is an independent journalist whose work has appeared in the Atlantic, The New York Times, Science, and many other publications. He is the author of "Eager: The Surprising, Secret Life of Beavers and Why They Matter" and the forthcoming "Crossings: How Road Ecology Is Shaping the Future of Our Planet" (W.W. Norton, September 2023).

This article was originally published on Undark. Read the original article.

By Ben Goldfarb

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