A leading environmental group on Monday called on authorities to keep tough fishing quotas on Atlantic tuna when governments meet next week to set industry rules.

The US-based Pew Charitable Trusts called on the 47-member governments of the International Commission for the Conservation of Atlantic Tunas to maintain catch limits on endangered bluefin tuna.

The group will meet in Cape Town next week under pressure from the fishing industry and countries to loosen rules.

"The recommended quotas should remain at current levels so that there is a stability," said Pew's Jamie Gibbon.

Since the industrial fishing era began, stocks of Bluefin tuna are thought to have fallen by at least 85 percent in the Mediterranean and eastern Atlantic, where they come to spawn in the warmer waters.

Some 80 percent of Atlantic bluefin tuna fished out of the Mediterranean ends up in the Japanese sushi market.

The European Union agreed in 2007 to restrict the fishing of bluefin tuna in the hope of reviving dwindling stocks, a measure which hit some member nations hard.

Fish stocks now seem to have stabilised, which a new scientific count is expected to confirm next February.

Spain, Portugal, Italy, Greece and Malta favour increasing quotas, although the EU as a whole is not in favour.

But Pew warned that the fish is not out of danger yet, citing a study which appeared to show fishing between 2008 and 2011 exceeded quotas by 57 percent.

"This will really be a test for governments to see whether they will be willing to follow science," said the organisation's Elizabeth Wilson.

Pew also called for curbs on porbeagle shark fishing, after the endangered fish was listed on the Convention for International Trade on Endangered Species (CITES) this year.