The world should ban the export of Atlantic bluefin tuna, a UN panel declared Friday, backing a proposal that is fiercely opposed by Japan, which prizes the fish as a key ingredient in sushi.

Atlantic bluefin populations have declined more than 80 per cent since the 19th century, so establishing special protections is justified by science, said CITES, the UN group that oversees the Convention on International Trade in Endangered Species.

"We are recommending that the parties accept the proposal," CITES scientific chief David Morgan told reporters in Geneva.

The tiny European principality of Monaco is asking the 175 nations that are members of CITES to agree on a global ban on Atlantic bluefin exports at a meeting in Qatar's capital of Doha from March 13-25.

The plan is one of 42 conservation proposals CITES members will consider, along with similar trade bans on products from polar bears, some sharks and other species.

The meeting will also decide whether to restrict or ease the ban on trade in elephant ivory, another hotly contested issue.

But the dispute over tuna — which pits most northern European countries against Japan and several Mediterranean fishing nations — will likely command the biggest attention because it threatens to wipe the iconic fish off the sushi menu.

Thousands of jobs

Turkey, Spain, Greece, Italy and Malta have thousands of jobs that depend on catching and shipping the fish to Japan, while France and Britain have signalled they would favour a ban.

A market worker holds a bluefin tuna caught in the Indian Ocean, early Friday, at the Rungis wholesale market, south of Paris. France favours a ban on the export of bluefin tuna but wants an 18-month delay before the measure would be imposed. (Christophe Ena/Associated Press)

Atlantic bluefin, which can reach three metres long and weigh more than 650 kilograms, fetch prices reaching 2,000 yen ($24 Cdn) a slice in high-end Tokyo restaurants. Japan buys 80 per cent of the world catch, with Europe, South Korea and the U.S. sharing the rest. In Europe, bluefin sushi is still rather rare, served only at the most exclusive restaurants.

The International Commission on the Conservation of Atlantic Tuna, which groups tuna-fishing nations, already sets quotas on the annual bluefin catch. It has reduced this year's limit to 13,500 tonnes, down nearly 40 per cent from 2009.

Environmentalists, however, say the quotas are widely ignored and are too high anyway.

"An Appendix I listing is now essential," said Steven Broad, head of the international monitoring group, referring to the category used by CITES for species that cannot be traded internationally.

Limited ban

An export ban on Atlantic bluefin wouldn't affect the Pacific bluefin species — even though that is similarly endangered — because there has been no proposal to limit its catch, said Morgan.

The bluefin ban also wouldn't cut sales of yellowfin, skipjack, or tongol tuna, which are commonly found in cans and deli sandwiches.

Atlantic bluefin "is a particular product from a very sought-after species (sold) in relatively small quantities compared with tuna generally," Morgan stressed.

He said the CITES office in Geneva wasn't recommending a similar ban on polar bear products, as proposed by the United States but resisted by Canadian indigenous communities.

CITES members will try to reach decisions by consensus, but if necessary they will hold a vote. Approval by two-thirds of those countries voting for or against is necessary to pass a proposal.

Round-about bribery possible

Other proposals up for debate include one by Tanzania and Zambia to permit them to sell government-owned stocks of ivory under a system allowing limited trade in the tusks of endangered elephants. Kenya and other African countries want all ivory sales halted immediately.

Meanwhile Sweden and Palau want to include dogfish, a type of shark commonly sold in British fish and chip shops, in Appendix II of CITES, which would require permits to trade.

CITES said it was aware of the possibility that lobby groups might try to influence countries' votes through round-about forms of bribery.

"We are trying to avoid as much as possible that lobbying groups finance the participation of delegations," said spokesman Juan Carlos Vasquez. "That doesn't exclude any illegality in their practices," he added.

The meeting will also look at ways of better enforcing already existing protection measures, such as the ban on trade in rhinoceros horns. Their use has shot up recently in Asia following unsubstantiated rumours that ground horn can halt the spread of cancer, said the group's chief enforcement officer, John Sellar.