Fishing of Atlantic bluefin tuna should be suspended to prevent the collapse of the species, campaigners have urged ahead of a meeting this week of the international body which regulates the fishery.
The Pew Environment Group wants the International Commission for the Conservation of Atlantic Tuna (ICCAT) to suspend the fishery until stocks have recovered and effective policies are in place to stop high levels of illegal fishing.
The environmental group also wants to see an end to fishing in spawning grounds which damage the fish's ability to breed.
Efforts to protect bluefin tuna through banning the international trade in the fish - which is a delicacy in Japan but which has seen numbers plummet over the past few decades in the face of overfishing - failed earlier this year.
Proposals to have the fish listed as endangered under the Convention on International Trade in Endangered Species (Cites) to temporarily stop the trade in the species were voted down at an international meeting in March.
Pew said countries attending the Cites meeting had claimed the way to manage stocks of the fish was through ICCAT.
Now the environmental group is calling for countries at the forthcoming ICCAT meeting, which takes place from Wednesday, to use the talks to secure a sustainable future for the bluefin tuna.
The group's senior policy adviser Remi Parmentier warned that scientists meeting last month to advise ICCAT on quotas for the fish had been forced to gaze into a crystal ball to estimate the amount that could be safely caught.
The scientists had come up with a best case scenario that quotas could remain at the current level of 13,500 tonnes, but that the margin of error was huge in the face of a lack of data and widespread illegal fishing.
He said: "We're asking for a suspension of the fishery because of the gaps in knowledge, the situation with illegal fishing and the fact that 85% of the resource has gone since the 1970s. Until Atlantic bluefin tuna have recovered and until reliable controls to avert illegal fishing are in place, it is reasonable to suspend the fishery."