 Concerns about the potential wildlife impact of the Dam predate the National People 's Congress 's approval in 1992 . This region has long been known for its rich biodiversity . It is home to 6 @,@ 388 species of plants , which belong to 238 families and 1508 genera . Of these plant species , 57 percent are endangered . These rare species are also used as ingredients in traditional Chinese medicines . Already , the percentage of forested area in the region surrounding the Three Gorges Dam has dropped from twenty percent in 1950 to less than ten percent as of 2002 , negatively affecting all plant species in this locality . The region also provides habitats to hundreds of freshwater and terrestrial animal species . Freshwater fish are especially affected by dams due to changes in the water temperature and flow regime . Many other fish are hurt in the turbine blades of the hydroelectric plants as well . This is particularly detrimental to the ecosystem of the region because the Yangtze River basin is home to 361 different fish species and accounts for twenty @-@ seven percent of all endangered freshwater fish species in China . Other aquatic species have been endangered by the dam , particularly the baiji , or Chinese river dolphin , now extinct . In fact , Government Chinese scholars even claim that the Three Gorges Dam directly caused the extinction of the baiji . 
