A bluefin tuna sold for a record $3.1 million at the first auction of the year at Tokyo's new fish market on Saturday, but behind the celebrations hides a worrying tale of overfishing and dwindling stocks.
Kiyoshi Kimura, who owns the Sushi Zanmai restaurant chain, paid 333.6 million yen for the 278kg fish at the first auction of the year, and the first to be held at Tokyo's new Toyosu fish market after last year's the move from the famous Tsukiji market.
The price at the predawn auction was nearly 10 times higher than the price paid at last year's auction - albeit for a considerably smaller fish - and roughly double the previous record, also set by Kimura, in 2013. There was an intense bidding war with a rival buyer who had won last year.
The winner said he was "very satisfied with the quality" of the fish but admitted he had paid much more than he had expected.
"The tuna looks so tasty and very fresh, but I think I did (pay) a little too much," Kimura told reporters outside the market later, according to news agencies.
Kimura said a single piece of the tuna would be served to customers in his restaurants later that day.
The fish was caught off the coast of northern Japan's Aomori prefecture by fishermen from the small town of Oma, which has a nationwide reputation for the quality of its tuna catch.
Bluefin tuna is highly valued for its taste in sushi restaurants, but decades of overfishing have sent stocks plummeting.
The IUCN Red List of Threatened Species classifies the Pacific Bluefin tuna, or Thunnus orientalis, as "vulnerable," with a decreasing population.
"The celebration surrounding the annual Pacific bluefin auction hides how deeply in trouble this species really is," said Jamie Gibbon, associate manager of global tuna conservation at The Pew Charitable Trusts. "Its population has fallen to less than 3.5 percent of its historic size and overfishing still continues today."
In response to the growing scarcity of the fish, Japan and other governments agreed in 2017 to strict quotas and restrictions on fishing, in an attempt to rebuild stocks from 20 percent of historic levels by 2034.
That has caused considerable unhappiness and some hardship in Oma.
Oma tuna is known as the "black diamond" of tuna, because fishermen still use traditional manual fishing methods, rather than trawling, allowing them to catch the fish intact.
But to stick to the quota, fishermen there said they decided to go slow in the summer and concentrate instead on fishing in the fall and winter, when tuna fetches a higher price. However, when they ventured out, they found tuna harder to find than usual and catches low, leading to fears in November that the Oma tuna could eventually disappear from the nation's sushi bars - although December's catch was better.
Hundreds of Japanese fishermen also protested against the new quotas outside the Ministry of Agriculture, Fisheries and Food in June, while Oma also canceled its annual tuna festival in October in protest.
But Gibbon lamented that Japan and other countries were already lobbying for higher catch quotas for 2019, just one year into the 16-year recovery plan, while also noting reports of Japanese fishermen discarding and not reporting dead bluefin to avoid exceeding their quotas.
"It's time for countries, including Japan, to support Pacific bluefin recovery, fund the necessary science, and commit to enforcing fishing limits, to ensure that there will still be bluefin left to auction," he said.
Pacific Bluefin tuna reach a maximum length of nearly 10 feet (3 meters) and a maximum weight of 550kg. A top ocean predator, they have been described as "twice the size of a lion and faster than a gazelle."
They are built like torpedoes, with a hydrodynamic shape, retractable pectoral (side) fins and, unlike other fish, eyes set flush to their body, according to WWF.
They have two main breeding grounds, off the coast of Japan. Most remain in the western Pacific all their lives, reaching from Russia's Sakhalin Island in the north to New Zealand in the south. But others, when they reach one to two years of age, make a 11,000km migration to rich waters off California and Mexico's Baja Peninsula, returning after two to four years to spawn in the same western Pacific waters where they began life, Pew Charitable Trusts say.
Pew says fishermen, mainly from Japan, South Korea and Mexico, often take fish before they reach maturity, which has badly undermined the population.
According to the Mongabay nature news website, bluefin are difficult to rear in captivity. With highly sensitive reactions to light and sound, they rarely spawn in captivity and often swim at top speed and die on impact with the sides of tanks or nets.