The Atlantic bluefin tuna, used to make sushi and sashimi, has been overfished and is at risk of commercial extinction, according to the environmental group WWF.

The group said despite efforts made by some governments, many regulators have not enforced quotas in an effort to accommodate the fisheries.

"Sustainable management of the world's tuna fisheries should be possible, if the will can be found," Dr. Simon Cripps, director of WWF's Global Marine Programme, said in a release.

"But many governments are routinely ignoring scientific advice, failing to implement the available conservation and management measures, turning a blind eye to illegal fishing and not prosecuting those who flout the rules."

Regional fishery management groups regulating the Atlantic, Pacific and Indian oceans are meeting in Kobe, Japan, this week to discuss problems in the fishing industry.

Co-operation needed: official

Japanese fisheries agency chief Toshiro Shirasu said he was deeply concerned about the diminishing global tuna stock in his opening remarks at the conference.

"We must strengthen our co-operation to tackle the issue," he said on Monday.

In October 2006, at the Commission for the Conservation of Southern Bluefin Tuna, Japan agreed to cut its southern bluefin tuna quota in half, acknowledging it had overfished the species.

WWF officials encouraged the fishery officials to focus their attention on the depleting tuna stocks and investigate different approaches to reduce the accidental capture of sharks, marine turtles, seabirds, small whales and dolphins in nets and hooks.

With files from the Associated Press