The Fisheries Agency is considering adopting annual catch limits for Pacific bluefin tuna, which according to an international conservation body is facing extinction, government sources said.
The new total allowable catch quotas, to be tested nationwide from July, would replace the existing framework of self-imposed guidelines adopted by parts of the fishing industry aimed at keeping in line with global limits.
The Western and Central Pacific Fisheries Commission tightened international limits in 2015 as the species remained under threat, halving the catch of bluefin tuna under 30 kg from the average caught between 2002 and 2004.
Japan's marine resources law already prescribes total allowable catch quotas for seven other species, including Pacific saury and a type of horse mackerel.
The law requires that catch levels be reported and imposes penalties for overfishing.
According to the sources, the one-year trial will see Japan's coastal areas divided into six regions to allocate quotas for fixed net fishing, with a separate quota imposed for purse seine fishing.
The International Union for Conservation of Nature classifies Pacific bluefin tuna as vulnerable, or at high risk of extinction in the wild in the medium-term future. Japan is the top consumer of the slow-growing fish, which is prized for sushi.