CHANGSHA: Billions of tons of waste dumped into China's longest waterway are taking a massive toll on its aquatic life, according to the first annual health report on the Yangtze River.

The river, the world's third longest, is hit by natural disasters, deterioration of water quality and loss of biodiversity, said the Yangtze River Conservation and Development Report 2007.

The nation's first comprehensive study of the river said that about one tenth of the 6,211 km main stream is in critical condition.

Almost 30 percent of its major tributaries, including the Minjiang, Tuojiang, Xiangjiang and Huangpu rivers, are heavily polluted by excessive ammonia, nitrogen, phosphorous and other pollutants, according to the report released at a forum over the weekend in Changsha, capital of Hunan Province.

"A direct result of pollution is shrinking fish catch," said Li Lifeng, freshwater program director of the World Wild Fund for Nature (WWF) China.

The river's annual harvest of aquatic products dropped from 500,000 tons in the 1950s to about 100,000 tons in the 1990s. "Fishermen along the river said even if they catch some fish from the polluted river, they dare not eat them," Li said.

The report was compiled by experts from the Chinese Academy of Sciences, the Yangtze River Water Resources Commission affiliated to the Ministry of Water Resources, and the WWF.

Last year, more than 26 billion tons of wastewater was pumped into the river, which runs through 11 provinces and municipalities.

Pollution, damming and heavy traffic have caused a dramatic decline in Yangtze aquatic life. Rare species such as the white-flag dolphin are thought to be on the verge of extinction and common species such as the carp are gasping for survival, the report said.

"The impact of human activities on the Yangtze water ecology is irreversible," said Yang Guishan, a researcher at the Nanjing Institute of Geography and Limnology affiliated to the Chinese Academy of Sciences and one of the chief editors of the report.

"It's a pressing job to regulate such activities in all the Yangtze drainage areas."

The report also warned of increased flood risks.

The Yangtze accounts for about 35 percent of China's total fresh water resources but it's also responsible for 70-75 percent of the country's floods, the report said.

Flood control remains an arduous task along the Yangtze, given the rising temperature and frequent occurrences of extreme weather over the last 50 years, said Yang.

Although the Three Gorges Dam has reduced flood risks in the middle reaches, the risk of flooding remains high in the lower reaches, he said.

Wang Shucheng, minister of water resources, said that pollution, floods, soil and water loss have become the bottleneck for the sustainable development of the Yangtze River Delta area which accounted for 40 percent of China's gross domestic product (GDP) in 2005.

To tackle the problems, the report suggests that the current governing body of the region be restructured to improve the integrated river basin management (IRBM).

"IRBM requires coordinating the management and development of the water, land, biological and related resources within a river basin, so as to maximize the economic and social benefits in an equitable way while at the same time conserving freshwater ecosystems, species and services," said James P. Leape, general director of WWF International.

The European Union has invested $33.7 million in the EU-China River Basin Management Program, undertaken in the Yangtze River and the Yellow River basins and launched in January this year.

Xinhua contributed to the story

(China Daily 04/16/2007 page1)