The World Wildlife Fund says the Yangtze is threatened by heavy damming, with dozens of dams already built or under consideration along the 5,500-kilometer river.

The group says the dams have forced at least one million people from their homes and are threatening the lives of many species, including a rare river dolphin and many water birds.

A new WWF report, Rivers at Risk, says while dams are good for irrigation and providing electricity, they create numerous environmental and social problems. Besides the Yangtze, the report identifies 20 other endangered rivers, including the La Plata, Tigris and Euphrates, Ganges, Amazon, Mekong and Danube.