Pollution and over-fishing in China's longest river, the Yangtze, have led to a dramatic depletion of aquatic life in the nation's mother river, said a newly-released report.

The report, entitled Maintaining the Health of the River and Developing a Harmonious Relation between People and Water, released by the Yangtze River Water Resources Commission, said there are now about 1100 aquatic species in the river, at least 100 fewer than in the 1990s.

Twenty fish species out of a total of 370 are on the endangered list, the report said.

"Although the Chinese paddlefish, white-flag dolphin, Chinese alligator, mullet and black finless porpoise can still survive and breed in the Yangtze River, their numbers keep dropping," said the report.

The white-flag dolphin is on the verge of extinction.

"Common species" such as carp are also gasping for survival.

The annual reproduction of fry of black carp, grass carp, silver carp and variegated carp has dropped from 30 billion in the 1990s to the current 400 million, said the report.

Overfishing is the major cause of the sharp decline, said Chen Yide, vice director of the Ministry of Agriculture's fishery bureau.

Over 250,000 people earn their livelihood from fishing the river, which far exceeds capacity, the official said.

The deteriorating environment of the Yangtze River is also having a drastic effect on the number of aquatic species, said the official.

According to the report, cities along the river discharge at least 14.2 billion tons of polluted water every year, 42 percent of China's total.

In 2003 the Chinese government instituted a fishing season system on the Yangtze River and released 500 million fish fry. However, aquatic life has not recovered and the situation remains critical.

(Xinhua News Agency September 29, 2006)