The Chinese called it baiji and "goddess of the Yangtze," and it was the only surviving member of a family of species that split off from saltwater whales and dolphins between 20 million and 40 million years ago. But now, according to a survey released in August, this rare freshwater mammal is almost certainly extinct — the first aquatic vertebrate species to disappear from the Earth in 50 years, and the first large mammal to fall victim to human impact. The multiple pressures: noisy boat collisions and dam construction that may have imperiled the sonar-driven animals, and overfishing — not for the dolphins themselves, but for river fish — with such indiscriminate techniques as netting, dynamite and powerful electric shocks. The disappearance of a top-level predator like the baiji — an indicator species that signals the health of its ecosystem — portends trouble for the Yangtze River and for the 400 hundred million people who depend on it.
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顶顶大腕卧底
