Environmental advocates have warned that a planned dam on the Yangtze River could lead to the extinction of a number of rare fish species, reported the Wall Street Journal.

The proposed Xiaonanhai Dam would be located 30km upstream of downtown Chongqing, which hopes to use electricity from the dam to meet its growing energy needs. Chinese officials are currently reviewing the project, and critics believe that preliminary approval could be reached soon.

Chinese and foreign scientists are concerned that the dam would encroach on a major rare-fish reserve that is home to 180 different fish species, including the already endangered Chinese sturgeon and the finless porpoise. The upper reaches of the Yangtze have a greater concentration of biodiversity than the middle and lower reaches.

Eight prominent Chinese scientists and environmental activists published an open letter in May urging the government to cancel plans for Xiaonanhai because it would destroy the river’s diverse aquatic life. International environmental groups such as the US-based The Nature Conservancy are also urging reconsideration of the plan.