Conservationists are worried the dam could threaten some fish species and drive the Chinese sturgeon to extinction.
According to a report on Yahoo Chinese environmentalists and scientists are trying to block the Xiaonanhai dam, near Chongqing city in western China.
They say that it and two other dams would flood the last remaining fish reserve on the Yangtze, preventing the migration of rare fish.
The Ministry of Environmental Protection's chief engineer, Wan Bentai, announced the environmental study and said the ministry has the power to reject the project if it is shown to be harmful to the environment, according to the report.
Environmental Study into Yangtze Dam
CHINA - The Chinese environment ministry has called for an ecological study over a proposal to build a dam on the Yangtze River.
