A five-day meeting aiming to reverse the decline in tuna stocks worldwide is under way in Kobe, Japan.
Conservationists say tuna is facing commercial extinction
Five regional bodies responsible for managing stocks of tuna, one of the most valuable and endangered species, are at the meeting.
They are to discuss plans to set up a global tracking system to certify the origin of every tuna that is sold.
Conservationists blame illegal and unregulated fishing and unsustainable quotas for tuna's dramatic decline.
In the western Atlantic, the number of bluefin tuna capable of spawning is less than one-fifth of what it was 30 years ago, according to the body that monitors fish stocks there.
In a statement issued at the start of the meeting, the environment group WWF said Atlantic bluefin stocks were at a dangerously low level.
"Atlantic bluefin, used for high-end sushi and sashimi, is massively over fished and the spawning stock of southern bluefin in the Indian Ocean is down about 90%," the statement said.
Certificates of origin
Last year, Japan admitted over fishing southern bluefin tuna and accepted a deep cut in its quota as punishment.
It called the meeting of the different bodies that regulate tuna fishing across the globe to discuss measures to ensure the survival of the species.
Delegates from governments and the fishing industry will discuss a proposal to force fishermen to produce certificates of origin for the tuna they catch.
This would expand conservation programmes already in place in some parts of the world.
It would go some way towards meeting the demands of conservation campaigners, like the WWF, who warn that tuna species face a high risk of what they call "commercial extinction" due to weak management of the industry.
The capacity of the world's tuna fleet is now far greater than that required to catch the legal quota, they say, and governments are not doing enough to implement conservation measures or to prosecute those fishermen who break the rules.