Alternatives should be considered before a hydropower project in the Yangtze River's conservation area moves ahead and endangers rare fish, scientists said.

The proposed site for the Xiaonanhai dam is in the experimental zone of the Upper Yangtze National Nature Reserve for Rare and Endangered Fish, triggering criticism from environmentalists and scientists.

"The project is very risky ecologically and economically," said David L. Harrison, former chairman of the Nature Conservancy, a non-governmental organization based in the United States.