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Tuna Helper: How a Fish Statistician Got Famous and Changed a Country's Mind

Toshio Katsukawa is working to get the Japanese to eat only fish whose populations aren’t endangered.
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Toshio Katsukawa writes a hugely popular blog about fish. (Photo: Toshio Katsukawa)

Toshio Katsukawa writes a hugely popular blog about fish. (Photo: Toshio Katsukawa)

On a clear evening last fall, an elegant contingent of Japan’s Who’s Who assembled in a blue-lit hotel ballroom overlooking a glittering waterfront in Yokohama, one of the country’s major port cities. At the center of the room, young socialites wielding selfie sticks circled Akie Abe, the first lady of Japan, like a hungry school of fish. Guests sipped cocktails and sampled sushi made only from abundant species of seafood. A steel-drum band serenaded the room to the peppy notes of “Under the Sea.” Toshio Katsukawa, a cheerful, square-faced man with a ready smile, and whose claim to fame is fish management, sat at the same table as the gamine movie star Ko Shibasaki.

The crowd was there to support Sailors for the Sea, an organization that is trying to get Japanese to eat only fish whose populations aren’t endangered. The guest list certainly included some of Katsukawa’s 25,000 Twitter followers.

The Japanese eat more fish per capita than almost any other industrialized nation. But Katsukawa, a Mie University marine scientist, has been trying, for more than a decade, to tell the nation that the future isn’t bright. The populations of many species are in free fall, including that of the Pacific bluefin tuna, the most highly prized sushi fish of all. His plainspoken blog, mostly containing fisheries statistics, has been making inroads. If you do an Internet search in Japanese on the topic of overfishing, Katsukawa is your top search result. (He jokes that he is the only search result.) In 2009, a group of about 400 pole-and-line fishermen—those who catch fish selectively, with rods, by hand—came to Katsukawa to tell him that the tuna were disappearing, and that their incomes had dropped by 75 percent in just three years. These fishermen worked from remote Iki Island in southwest Japan, close to a spawning ground for Pacific bluefin (some of which spend a lot of time migrating between Japan and California and Mexico—except when they're spawning). In 2004, industrial fishing boats showed up near the island, using sonar to track the schooling tuna. The next year, the tuna population started to plummet.

About 400 pole-and-line fishermen came to Katsukawa to tell him that the tuna were disappearing, and that their incomes had dropped by 75 percent in just three years.

This problem, though, has been touchy for the government and local scientists. Criticism of Japanese fishing practices has often been interpreted as an attack on Japanese culture. Consider the Oscar-winning film The Cove, wildlife organizations like Sea Shepherd—which have been accused of being anti-Japanese—and the television show Whale Wars. “Many Japanese believe that the U.S. protests Japanese whaling in order to sell its beef to Japan,” Katsukawa told me recently. “That’s why young Japanese support whaling, even if they do not eat whale.”

In 2009, Katsukawa says, no Japanese scientist admitted that the Pacific bluefin were in trouble. Katsukawa knew, though, that critical words coming from the mouths of the Japanese fishermen themselves would be powerful. “Japanese are serious about eating—they become crazy when they know some food item is disappearing,” he told me. At this point, the public was pretty much ignorant about the domestic overfishing problem. Which gave him an opportunity.

Katsukawa started talking with small groups of fishermen about managing fish stocks by putting quotas on the number of fish that could be caught each year so that populations had time to rebound. He explained how in Norway fishermen now profit (a lot) from restrictions that allow them to catch big, high-quality fish by avoiding young fish. And he did the math. Fishermen were catching mostly young bluefin, killing them before they could reproduce.

A three-kilogram juvenile bluefin sells for 500 yen per kilo; if you wait six years, the fish grows into a 100-kilo fish that sells for 5,000 yen per kilo, Katsukawa says. That’s a tenfold increase in price per kilogram, and a nearly 100-fold gain in total profit, on a single fish. And because the fish will have had a chance to reproduce, the population can sustain itself. Everybody wins.

With that knowledge, the fishermen began lobbying the government. At Tokyo’s influential Tsukiji fish market, where most of the Pacific bluefin in the world is bought at auction and shipped to restaurants around the world, a cooperative of 40,000 fish traders, buyers, and consumers signed a petition supporting government regulation of the juvenile bluefin catch, and of the spawning grounds. Katsukawa was kept busy explaining statistics at meetings between fishermen and the government. Then, in 2010, the local media began to pay attention.

Last year, the government announced new limits on the catch of juvenile Pacific bluefin, and Katsukawa is now teaching fish population management to a government study group. (About the new restrictions, Katsukawa says that “it’s better than nothing,” but adds that the number of fish fisherman can catch is still too high.)

Tuna traders at Tsukiji and other groups have been advocating for the wide adoption of labels that show buyers that well-managed seafood is a virtue. Katsukawa thinks that the 2020 Tokyo Olympics may be a good opportunity to use labels for a bit of “shocking and shaming”—making it plain that many of Japan’s fish don’t meet international standards of responsible fishing.

The celebrity effect, too, can’t be discounted. In recent years, Yao Ming has made inroads in China as a spokesman for WildAid’s campaign against the practice of cutting the fins off sharks for use in food and medicine; his clout with young Chinese helped shift the perception of eating shark fin from a symbol of prosperity to something that, to a younger, educated class, is now considered shameful and ignorant.

At the star-studded Yokohama gala, before dinner was served, Katsukawa sat quietly, watching as Japan’s beloved first lady took the podium to welcome the room. Five years ago, the event—and Mrs. Abe’s very visible support of marine conservation—wasn’t even a glimmer in Katsukawa’s eye. As he listened, he found himself thinking that Japan might actually have a chance to turn the tide.


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