The population of bluefin tuna in the Mediterranean Sea is plummeting and could be seeing the start of a collapse, warn experts from the International Commission for the Conservation of Atlantic Tuna and the World Wildlife Fund. High-end sushi restaurants in Japan fuel demand for premium catches of the fish, which can net some $15,000 each for the biggest and best. Demand, as well as the improved technology of fishing fleets that regularly exceed already-high quotas, has had a negative effect on tuna stocks. The relatively new method of tuna ranching has also played a noticeable part in the decline. Fishers corral whole schools of tuna into huge cages, fatten them up, and take them to market. Last month, the ICCAT banned bluefin fishing for the rest of 2007 so stocks can have a chance to recover. “When you are down at very low biomass levels all it takes is one or two bad years to start the downward spiral from which it would be difficult to return,” said ICCAT scientist Gerald Scott.

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