Fishmongers check the quality of meat on large tuna fish at this year's first trading day at Tokyo's Tsukiji fish market, January 2008. The rage for sushi and sashimi, Japan's raw fish dishes that overtook the West and have now spread to increasingly prosperous China, risks wiping out one of the Mediterranean's most emblematic residents: the bluefin tuna.
The rage for sushi and sashimi, Japan's raw fish dishes that overtook the West and have now spread to increasingly prosperous China, risks wiping out one of the Mediterranean's most emblematic residents: the bluefin tuna.
Experts say too many of these majestic fish prized since Greek and Roman times -- each one of which can weigh up to 900 kilos (nearly 2,000 pounds) -- are ending up on the platters of restaurants around the globe.
"Japanese consumption was already a threat to bluefin tuna in the Mediterranean. The European craze for sushi bars has added to that," said Roberto Mielgo Bregazzi, a Spanish expert and author of several reports for Greenpeace and the World Wildlife Fund.
And "if the Chinese market continues to grow, that will be the end of the stock," he said.
Eating Japanese-style raw fish in rice packages spread to Europe and the United States in the 1990s and quickly grabbed palates there.
China seems to be next, according to Bregazzi who said there had been a significant increase in tuna consumption there in the past six years. Even though there are few official figures on Chinese consumption, the trend has also been observed by the International Commission for the Conservation of Atlantic Tunas (ICCAT), a body responsible for managing bluefin tuna fishing.
Japan, however, remains the main consumer of bluefin tuna. "Around 80 to 85 percent of bluefin tuna caught in the Mediterranean is exported to Japan," said Jean-Marc Fromentin, a leading worldwide expert on the subject at the French Research Institute for Exploitation of the Sea (IFREMER).
Sushi consumption took off after World War II, largely using southern bluefish tuna then found in huge numbers off the coast of Australia.
"This stock has now collapsed thanks to over-fishing, and the Japanese turned their attention to the Atlantic bluefin tuna," said Fromentin, adding that despite its name, Atlantic bluefin comes mainly from the Mediterranean.
Prices began to climb. Fishing fleets were modernised in Europe, and new fishing fleets created in Turkey and northern Africa. The result -- a huge over-capacity in fishing.
Today more than 50,000 tonnes of bluefin tuna are caught every year in the Mediterreanean. To prevent stocks from collapsing, that figure should be limited to 15,000 tonnes in the short term, according to ICCAT.
"The bluefin tuna industry is in the process of fishing itself to death," said Greenpeace oceans campaigner Karli Thomas.
The risk now is that the depletion of tuna will wipe out the fishing sector, and cost thousands of jobs in the Mediterranean region.
The big firms push fishermen into over-fishing --
In May and June, fishermen from France, Italy, Libya, Malta, Spain, Tunisia and Turkey are under pressure to maximise their catch. Most use a net called a "purse seine", which is weighted to reach the sea floor, with hoops and ropes which allow the fishermen to pull the drawstrings and trap the bluefin tuna within the net.
They work out of ultra-modern trawlers, up to 60 metres (196 feet) long and costing around five million euros (eight million dollars).
At this point in the chain, a kilo of bluefin tuna fetches the fisherman between eight and 10 euros.
The catch is sold to tuna fattening farms, many located in Cypriot, Croatian, Maltese, Sicilian, Spanish and Tunisian waters and many owned by Japnese companies like Mitsubishi, Maruha or Mitsui or the Spanish group Ricardo Fuentes e Hijos.
The tuna are transported to these offshore farms in huge circular cages 50 metres in diameter and 23 metres deep. Once in the tuna farms, or ranches as they are sometimes known, the tuna gorge on tonnes of sardines, mackerel and herring.
This boosts their weight to the demands of the Japanese buyers. Some farms also feed the tuna freeze-dried garlic to stimulate their blood circulation, or prawns to boost their reddish tinge.
It takes between nine and 20 kilos of small fish to put a kilo of weight on to a bluefin tuna, according to a co-owner of the Fish and Fish Farm in Malta, Joseph Caruana.
The fattened tuna are then sold at around 13 euros (20 dollars) a kilo to Japanese buyers, who in turn sell them for a much higher price in Tokyo -- where a good quality, 200-kilo tuna can fetch up to 20,000 euros.
"It is the big firms that push the fishermen into over-fishing," said Bregazzi.
In theory, the bluefin tuna harvest is monitored so that the ICCAT quotas are respected. But there are numerous flaws.
This year, the European Commission -- the EU executive -- has clamped down somewhat. Fishing was even put on hold for 15 days for some countries -- a decision which infuriated French and Italian fishing fleets in particular.
"But the Turkish tuna seiners continued to fish, and there is always the illegal fishing by Japan and Korea," said French fisherman Andre Fortassier.
Fishing and farms have also developed in non-EU countries in recent years, including Libya, Tunisia and Algeria where quota controls tend to be looser, industry sources say.
For Sergi Tudela, a Spanish marine biologist with Worldwide Fund for Nature (WWF), the responsibility lies with ICCAT.
"If important parties in ICCAT such as the US, the European Union and Japan decide to put an end to this unsustainable situation and to adopt real recovery measures, the other countries should accept them," he said.
"Japan is the key market. If there is a real willingness from Japan to ensure that only real sustainable production is being imported, they can implement that," he added.
"The potentiality is there, it only lacks political will."