A bluefin tuna sold for a record $1.76 million at a Tokyo auction Saturday, nearly three times the previous high set last year – even as environmentalists warn that stocks of the majestic, speedy fish are being depleted worldwide amid strong demand for sushi. In the year’s first auction at Tokyo’s sprawling Tsukiji fish market, the 222-kilogram (489-pound) tuna caught off northeastern Japan sold for 155.4 million yen, said Ryoji Yagi, a market official. The fish’s tender pink and red meat is prized for sushi and sashimi. The best slices of fatty bluefin — called “o-toro” here – can sell for 2,000 yen ($24) per piece at upmarket Tokyo sushi bars. Japanese eat 80 percent of the bluefin tuna caught worldwide, and much the global catch is shipped to Japan for consumption. The winning bidder, Kiyoshi Kimura, president of Kiyomura Co., which operates the Sushi-Zanmai restaurant chain, said “the price was a bit high,” but that he wanted to “encourage Japan,” according to Kyodo News agency. He was planning to serve the fish to customers later Saturday. Kimura also set the old record of 56.4 million yen at last year’s New Year’s auction, which tends to attract high bids as a celebratory way to kick off the new year – or get some publicity. The high prices don’t necessarily reflect exceptionally high fish quality. The price works out to a stunning 700,000 yen per kilogram, or $3,603 per pound. Stocks of all three bluefin species – the Pacific, Southern and Atlantic – have fallen over the past 15 years amid overfishing. On Monday, an intergovernmental group is to release data on Pacific Bluefin stocks that environmentalists believe will likely show an alarming decline.