Sushi chain operator Kiyoshi Kimura netted a real bargain on Sunday, taking home a 507 pound (230 kilogram) bluefin tuna for a mere 7.36 million yen (about $70,000), a fraction of the price he paid last year at the year's first auction at the Tsukiji market in Tokyo.

The auction attracts high bids as a celebratory way to launch the new year, but Kimura's winning bid last year of 154.4 million yen for a 222 kilogram fish drew complaints that prices were way out of line.

"I'm glad that the congratulatory price for this year's bid went back to being reasonable," said Kimura, whose Kiyomura Co. operates the popular Sushi-Zanmai restaurant chain.

Environmentalists say growing worldwide consumption of bluefin tuna is leading to its depletion. Japanese eat about 80 percent of all bluefin tuna caught worldwide.

There were 1,729 tuna sold in Sunday's first auction for 2014, according to data from the city government, down from 2,419 last year. The 32,000 yen ($305) per kilogram paid for the top fish this year compares with 700,000 yen per kilogram last year.

According to a stock assessment by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean, the bluefin tuna population is at less than 4 percent of its unfished size.