Stocks of Pacific bluefin tuna, which this nation consumes in large quantities — equivalent to 80 percent of the world's total catch — are now critically low and no optimism is warranted for their recovery. The Fisheries Agency is introducing a new system to control catches, but it needs to make serious efforts to ensure that its steps will be effective in restoring Pacific bluefin stocks. The agency will face severe criticism not only from domestic fishermen but also from the international community concerned with conservation of the species if the new steps fail to bring about tangible results.

In 2014, the International Union of Conservation of Nature put the Pacific bluefin tuna on its list of threatened species, warning that its population has declined between 19 and 33 percent over the past 22 years and that the condition of the stock is unlikely to improve since the number of new fish added to the fishable population each year, a process known as "recruitment," is low. The annual catch has declined to as low as 15,000 tons from its 1981 peak of 35,000 tons in the Pacific Ocean.

According to an assessment released in April by the International Scientific Committee of Tuna and Tuna-like Species in the North Pacific Ocean (ISC), the Pacific bluefin tuna population has fallen to just 2.6 percent of its population before large-scale commercial fishing started. The total stock of mature fish that can spawn stood at 16,557 tons in 2014, down 90 percent from 160,005 tons in 1961, though slightly up from 13,795 tons in 2012. The ISC pointed out that the population was less than a third of the level just 20 years earlier and estimated that there were approximately 110,000 adult Pacific bluefin tuna remaining in the entire Pacific Ocean.