水电站及环境污染.doc

WWF Says Pollution, Dams Threaten Rivers By ELIANE ENGELER, March 19, 2007. GENEVA - The Yangtze River gets more than half of Chinas industrial waste and sewage. Europes Danube has lost most of its surrounding wetlands. And the Rio Grande has become so shallow that salt water is seeping in, bringing ocean fish that threaten freshwater species. Pollution, global warming and rampant development could destroy some of the worlds most iconic rivers in the coming decades, threatening to wipe out thousands of fish species and cause severe water shortages, the World Wide Fund for Nature said in a report Tuesday. Only 21 of the planets 177 longest rivers run freely from source to sea, with dams and other construction destroying the habitats for migratory fish and other species by altering the waters natural ebb and flow, the WWF said. About a fifth of the worlds 10,000 freshwater fish and plant species are either extinct or endangered, the report said, calling on governments to radically step up efforts to preserve rivers, lakes and wetlands. Unabated development is jeopardizing natures ability to meet our growing demands, said Jamie Pittock, who heads WWFs freshwater program. The report focused on some of the worlds most important rivers: the Nile, the Danube, the Rio Grande, South Americas La Plata, Australias Murray-Darling and Asias Yangtze, Mekong, Salween, and Ganges rivers. The Danube — home to more than half of Europes fish species — has lost 80 percent of its surrounding wetlands and flood plains because of dams, the report said. Construction to ease shipping channels — dredging, pumping water or straightening banks — also threaten animals and plants in the river, which runs from Germany to the Black Sea, WWF said. Less than 7 percent of its basin is protected. In China, pollution in the main stem of the Yangtze River has increased by more than 70 percent over the last 50 years. Almost half of the countrys industrial waste and sewage is discharged in the river, th