Shark fin soup (or shark's fin soup) is a popular soup in Chinese cuisine. It is usually served at special occasions such as weddings and banquets. The shark fins provide texture, while the taste comes from the other soup ingredients. The soup was first mentioned centuries ago as a favorite of Chinese Emperors. It costs up to $100 a bowl. But it has a much higher environmental cost. About 70 million sharks a year are killed for their fins. Currently about 25% of sharks are threatened species.