The 51-nation tuna fisheries body for the Atlantic and Mediterranean boosted quotas for highly prized bluefin despite scientific findings that doing so could threaten the species' recovery, delegates and observers at a key meeting said Tuesday.

Country quotas for eastern bluefin tuna are to increase 50 percent, by increments, to 36,000 tonnes in 2020, sources told AFP at the conclusion of the closed-door meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT).

The warm-blooded, fatty fish -- which can grow to the size of a small car and swim nearly as fast -- underpins a billion-dollar business, and is a culinary mainstay in Japan.

ICCAT also gave the go-ahead for bigger catches of western bluefin tuna, as well as so-called tropical tunas, despite evidence of declining stocks and over the objections of some members.

ICCAT's scientific committee, meeting last month in Madrid, approved the higher catch figures for the iconic eastern bluefin.

At the same time, however, it concluded that -- for bluefin stocks to have even a coin's toss chance of continued growth -- total allowable catch should be held to 28,000 tonnes.

The contradictory findings point to a breach in the "firewall" between the scientific committee and the political body to which it reports, members of both groups said.

"This year was an enormous step backwards for sustainable tuna fisheries," said Paulus Tak, a senior officer for the Pew Charitable Trusts, and an official observer at the ICCAT talks.

"In the vast majority of ICCAT decisions this year, the status of the stocks was ignored."

The new quotas -- allocated mostly to the European Union, which pushed hard for the increase -- "further undermine the credibility of the Commission," he added.

Industrial-scale tuna fisheries in Spain, Italy and France all have outsized political influence in shaping policy, analysts say.

A decade ago, eastern bluefin was on the brink of collapse. In 2010, the UN body governing trade in endangered species considered a motion to outlaw international sales of the fish, which can fetch tens of thousands of dollars for a single specimen. 

The motion failed, but prompted ICCAT to lower quotas and crack down on illegal fishing.

The measures worked, but not well enough to declare the stocks fully recovered in 2016.

- 'One man, one hook, one fish' -

 

Quotas for western Atlantic bluefin were also increased, to 2,350 tonnes, despite the fact that stocks are only 18 percent of 1950 levels after a 20-year "rebuilding plan".

"This is likely to result in further declines of biomass," Tak told AFP.

ICCAT also shot down a proposal to slow the harvest of bigeye, skipjack and yellow tail.

The $3.4 billion (2.9 billion euro) market for these so-called tropical tunas is several times bigger than for bluefin, but gets far less attention.

The proposal from South Africa -- backed by Brazil, Japan and several other African nations -- would have reined in industrial purse seine fishing, in which factory ships cast enormous nets that scoop up hundreds of fish at a time.

"It is only a slight exaggeration to say that they catch more fish in a single outing than we do in a year," said Portuguese delegate Luis Rodrigues, Director of Fisheries for the Azores, an island chain in the Atlantic 1,700 kilometres (1,000 miles) west of the Strait of Gilbraltar. 

The European Union "made sure the proposal was shelved," said one delegate, who asked not to be named.

The Azores and neighbouring Madeira islands use a more traditional form of "one-by-one" tuna fishing -- "one man, one hook, one fish," Rodrigues said.

But their relatively modest catch -- which employs 10,000 people locally -- has diminished by half every year over the last half-decade, from 4,800 tonnes in 2012 to 345 tonnes last year.

The problem, they said, is purse seine nets scooping up the fish, especially juveniles, off the coast of Africa before then can migrate into Azores waters.

"I am really afraid that artisanal fisheries like ours are going to die," said Pedro Capela, Head of the Tuna Association of the Azores.

"If nothing changes, in a few years this kind of fishing will be dead, I'm sure of that