Their fins, prized for shark-fin soup, a traditional Chinese dish, fetch high prices.

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John McCosker, chairman of aquatic biology at the California Academy of Sciences, estimates that 90% of the sharks that once inhabited the world's oceans have now disappeared, due to overfishing and shark finning a practice in which sharks are captured and their fins are sliced off for use in shark-fin soup.

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See his heartfelt anti-shark fin soup public service announcement here.

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"Sharks are still hunted in some waters as part of the finning industry where, horribly enough, they take the fins for shark fin soup and discard the rest of the body - that is the biggest threat to all sharks worldwide, " she said.

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At a spring festival gathering in February, the Hong Kong Pui Ching Alumni Association ordered a 10-course meal but opted to replace the shark's fin soup with a chicken, fish belly and abalone soup.

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