A UN scientific agency has backed a proposal to ban international trade in Atlantic bluefin tuna, saying the species prized by sushi lovers need to recover from commercial overfishing.

Monaco had proposed protecting bluefin tuna, which can fetch up to $100,000 in Japan, by listing it under appendix I of the Convention on International Trade in Endangered Species (CITES).

“In our opinion, the criteria for including the species in appendix I are met and international commercial trade in bluefin tuna should be prohibited,” David Morgan, head of CITES’ scientific unit, told a news briefing.

Some 175 countries are due to vote on 40 proposals during the CITES triennial meeting in Doha, Qatar, from March 13-25.

The Swiss-based treaty body, which regulates international trade in wildlife, seeks consensus on its regulations to conserve and sustainably manage 34,000 animal and plant species.

Some 530 animals species — including all the great apes, cheetahs, the snow leopard, the tiger, and all sea turtles — as well as 300 plants are on its appendix I banning international commercial trade in species deemed under threat of extinction.

But Japan strongly opposes the bluefin ban and in order for it to be adopted, a two-thirds majority is required.

Atlantic or northern bluefin tuna is found throughout the North Atlantic and its adjacent seas, particularly the Mediterranean, but also in the Gulf of Mexico and Straits of Florida. It can reach a weight of more than 650 kilograms.

France, Italy and Spain account for half of the world’s total allowable catch of bluefin tuna. Japan imports some 80 per cent of the total catch.

The tuna currently fetch $200 to $300 per kg, according to a CITES document prepared for the Doha meeting.

“It is a very small part of the overall market of overall trade in tuna. It is the top end of the market, the luxury tuna,” Morgan said.

“A great majority goes to Japan because prices are higher there. The Japanese are by far the biggest consumers, they have a key role in trade in these species.”

Atlantic bluefin tuna stocks have declined by more than 80 per cent since 1970, according to CITES, which estimates current stocks at 3.17 million.

The official quota for 2009 was 19,950 tonnes, set by the International Commission for the Conservation of Atlantic Tunas, but the true annual catch is estimated at around 50,000 tonnes.

France is on record that it would support a ban on global trade in bluefin tuna, but only after an 18-month delay.

CITES rejected a separate proposal from the U.S. to impose a ban on international trade in polar bears and their skins due to their shrinking numbers and the threat posed by climate change to their ice platforms in many regions of the Arctic.

“There will be quite a controversy, this is an iconic species and there are lots of pressures from both sides. This has livelihood implications for indigenous people in Canada,” said CITES spokesman Juan Carlos Vasquez.