Minoru Nakamura, a fisherman from Iki Island, recalled the biggest tuna he had ever caught, back in 2013. “It weighed 319 kilos. It was so big I couldn’t get it into the boat, and I had to lash it to the hull.” A fish this size being rare, it made the front page of the local newspaper. A photograph showed Nakamura next to his enormous catch, 2.7 meters long, hanging from a crane. He looked proud, but not ecstatic: Their precarious livelihood makes these independent fishermen humble. “I can go for ten weeks without catching anything,” he said at the time; today that sounds like a prophecy. This remarkable fish was one of the last Pacific bluefin tuna over 300 kilos to be caught off Iki.
Iki (population 27,000), in the Sea of Japan between Korea and the Japanese city of Fukuoka, is a pleasant subtropical island with green hills, hot springs, rice paddies, and white sand beaches, but its fishing community is facing an existential crisis. The annual catch of bluefin, highly prized by sushi lovers, has plummeted: It fell from 358 tons in 2005 to less than 23 tons in 2014. Nakamura said: “The little fish, weighing 3-4 kilos, were the first to go, then the bigger ones, and now there are none at all.”
Nakamura and his colleagues have petitioned the Fisheries Agency, part of Japan’s agriculture, forestry, and fisheries ministry, several times. The agency maintains that falling catches are due to climate change. “They say the tuna have moved to the waters off Korea, where we’re not allowed to fish,” said Nakamura, who doesn’t believe it. The fishermen blame the powerful industrial fishing vessels operated by big companies like Nippon Suisan Kaisha (Nissui), which has 10,000 employees. These come from Sakaiminato, a mainland port 400 kilometers northeast of Iki. They started catching adult tuna in the Sea of Japan in 2004, the year Iki’s fishermen began to see their catch fall. Sakaiminato vessels seek out schools of tuna with sonar, then encircle them with a purse seine more than 1 kilometer in circumference. They catch up to 50 tons each time they deploy the net, and a total of 1,500 tons in June and July, when they fish most intensively. The Iki fishermen, who use pole and line, rarely catch more than 1.2 tons a month per boat.
Such intensive fishing is “a heavy burden on the environment,” says Kazue Komatsubara, an ocean campaigner with Greenpeace Japan. “It allows them to catch large numbers of fish of all sizes and species.” According to a report by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC), nearly 60 percent of all tuna landed by Japanese vessels in the last three decades have been caught by this method.
Many of the bluefin that roam the Pacific Ocean return to the Sea of Japan every summer: This area and the northern part of the Philippine Sea are their spawning grounds. All the fishermen of Sakaiminato have to do is wait with their nets. Their methods anger environmental activists and researchers, who blame them for the decline of the species. “Intensive fishing of tuna during the spawning season is very harmful to the health of the species,” said Toshio Katsukawa of the University of Tokyo’s Atmosphere and Ocean Research Institute. “It’s the complete opposite of sustainable, and if it continues, it will lead to the collapse of the fishing industry in the region. The government should ban the practice.”