A third of all fish species in the Yellow River, China's second longest, have become extinct because of dams, shrinking water levels, overfishing and pollution, state media said on Thursday.
The 5,464-km (3,395-mile) river, which supplies water to over 150 million people and irrigates 15 percent of the country's farmland, was once known as "China's sorrow" because of its flooding, but in recent years has occasionally run dry before reaching the sea.
"The Yellow River used to be host to more than 150 species of fish, but a third of them are now extinct, including some precious ones," the People's Daily quoted an unnamed Agriculture Ministry official as saying.
Fishing has also dropped, falling 40 percent from an annual average of 700,000 kgs (700 tonnes) in the past, the newspaper said.
"It can be mainly blamed on hydropower projects that block fish's migration routes, declining water flow caused by scarce rainfall, overfishing and severe pollution," the official was quoted as saying.
The flow of the river, which wanders across parched northern China, hit a historic low in the first 10 months of 2006.
China has been engaged in a construction craze of hydropower plants in past decades, with an official mindset in which energy and economic benefits of the dams easily outweigh the possible negative environmental impact.
The country's economic boom has also peppered its rivers with factories, many of which lack proper wastewater treatment facilities and put "cancerous" pollution into the rivers.