By Anna-Marie Lever
Science and nature reporter, BBC News
The US is calling for a ban on the fishing of bluefin tuna in the eastern Atlantic and Mediterranean Sea.
Delicious to eat - but an endangered species
A three-to-five-years ban is being proposed to the International Commission for the Conservation of Atlantic Tunas (Iccat).
The call comes amid deep concerns that the stock may collapse if the level of overfishing continues.
The European Commission recently closed its bluefin tuna fishery for this year after quota limits had been exceeded.
Bill Hogarth, the US delegate and Iccat chairman, said: "We need a determined international effort to save this truly magnificent fish".
The US Senate has backed Mr Hogath's calls for a moratorium on bluefin tuna fishing at the Iccat, which is currently meeting in Turkey.
Conservation group WWF has given its support to the US proposal.
It too has been calling for an immediate three-year ban "following a season of unprecedented illegal and uncontrolled fishing which has resulted in massive over-quota catches".
Speaking from Turkey, Dr Sergi Tudela, the head of Fisheries Programme at WWF Mediterranean said:
"The so-called recovery plan that was adopted by Iccat last year, is not a recovery plan - it is a collapse plan, even according to the scientific committee of Iccat," he told BBC News.
In 2006, to stop stock decline, Iccat scientists advised that the total catches on eastern Atlantic and Mediterranean bluefin stock should not exceed 15,000 tonnes.
The adopted plan, however, set the quota at 29,000 metric tonnes for 2007, nearly twice the scientifically recommended level.
These unsustainable management measures, along with violations of catch limits, illegal fishing and misreporting mean the US and WWF believe a moratorium is the only option to save blue fin tuna stocks from collapse.
TUNA CATCHES 2007 (IN TONNES)
Total ICCAT quota: 29,500
EU ICCAT quota: 16,779
Illegal and unreported catch estimate: 20,500
(Sources: WWF, Noaa, Reuters)
Time to vote
The Iccat is made up from 45 member nations, which includes the European Commission.
The vote from the Iccat will be announced at the end of the meeting on Sunday.
Dr Tudela said: "So far it looks difficult to get the minimum support required for this [temporary moratorium], but we don't know yet. We will know very soon which countries are supporting this."
Turkey and Japan have also made proposals.
Turkey has called for the management plan adopted by Iccat last year to be amended by reducing quotas previously enforced by 5,000 tonnes and extending the closed fishing period.
Japan wants to establish a working group of traders and farmers to determine a management plan alongside Iccat.