Against the backdrop of an apparent Atlantic bluefin tuna recovery, fishing nations gather in Genoa, Italy, next week to set new limits, closely watched by environmental groups and scientists.

In 2013, the bluefin tuna spawning stock in the east Atlantic and Mediterranean surged to 585,000 tonnes -- nearly double the levels of the 1950s, according to International Commission for the Conservation of Atlantic Tunas (ICCAT) -- though actual counts are hard to do.

The stock had been decimated by fishing boats to a low 150,000 tonnes in the mid-2000s.

"There are positive signs of the stock recovering, but it is not yet at 100 percent," said Sylvain Bonhommeau, a researcher at the French ocean institute Ifremer and a member of ICCAT's scientific committee.

At its 2012 meeting, the commission had decided to raise catch limits to 13,500 tonnes annually for fish taken in the Mediterranean and east Atlantic for 2013 and 2014, up from 12,900 tonnes.

At a seven-day gathering starting Monday, the commission's 48 members (47 nations and the European Union) will put forward their quota demands.

France, one of Europe's biggest fishing nations, wants a 18,500-tonne limit for 2015, and 23,500 tonnes for the year thereafter.

In the 1990s, a quota of about 50,000 tonnes per year saw the much-prized but threatened species known to scientists as Thunnus thynnus stretched to the limit.

The ICCAT quota for 2008 was 28,500 tonnes, followed by 22,000 tonnes in 2009, and 12,900 in 2011.

"It is going to be very tough," said Amanda Nickson of Pew Environment, which opposes a higher limit, said of next week's gathering.

"The latest stock assessment seems to indicate things are improving. In part this is good news... however the scientists said they don't know how much of an increase there is and they can't agree on how much higher the quota could be," she told AFP.

- Not there yet -

"There is severe industry pressure now, with the industry saying there is more fish we should be allowed a higher quota. And so the test this year for the governments of ICCAT is: are they going to continue to follow the science and allow this recovery to happen, or are they going to risk sliding back to the bad days and raise the quota too soon?", Nickson said.

Greenpeace's Francois Chartier underlined that the "stock is busy recovering, but hasn't recovered yet".

Not only have stricter quotas helped, but also naval patrols to enforce the limits.

The Atlantic bluefin tuna was in 2011 listed as endangered by the International Union for the Conservation of Nature (IUCN).

ICCAT's members include Britain, Canada, China, Russia, the United States, several Mediterranean countries, the EU and Japan, which single-handedly consumes over three-quarters of all the bluefin tuna caught, according to green group WWF.

The Atlantic bluefin can live up to 40 years and grow to more than four metres (13 feet) long.

The fish spawn just once a year and do not reach reproductive maturity until they are eight to 12 years old, making them more vulnerable to overfishing than smaller species which spawn more frequently.