Japan is the world's biggest consumer of seafood, with Japanese eating 80 percent of the Atlantic and Pacific bluefins caught. The two tuna species are the most sought-after by sushi lovers.
Fatty bluefin — called "o-toro" here — can sell for 2,000 yen ($24) per piece at high-end Tokyo sushi restaurants.
Japanese wholesalers, however, face growing calls for tighter fishing rules amid declining tuna stocks worldwide.