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2013四级翻译白暨豚真的灭绝了吗
Since November 6, a team of scientists from China, Switzerland, the United Kingdom, the United States, Germany and Japan have been searching for any sign of the freshwater dolphin on the middle and lower sections of the river. After six weeks, they came back empty-handed.
Wang Ding, of the Chinese Academy of Sciences, who is the head of the team, said he has seen a sharp decline in the baiji population over the past few decades. However, he is still unwilling to call the species extinct, and adds, "We will try every effort to save them as long as they are not found to be extinct."
The baiji is shy and nearly blind and is one of the world's oldest dolphin species. It dates back some 20 million years and is found only in the Yangtze. It's listed as one of the 12 most endangered animal species in the world.
Around 400 baiji were believed to be living in the Yangtze until the 1980s. A 1997 survey spotted 13. Two years later their numbers were down to two.
The rapid disappearance of this dolphin over the past two decades coincided with the rapid expansion of economic development along the river. Research on some dead baiji collected in recent years showed that more than 90 per cent of the deaths were caused by human activities.
One reason is that over-fishing has cut the dolphin's food sources. Dams built along the river and neighbouring waterways have also kept them from swimming into and out of their habitats. Meanwhile, waste discharge has seriously polluted the river. And heavy river traffic has greatly reduced their living space.
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