Recent monitoring of the white- fin dolphins in the Yangtze River indicates that their number is decreasing dramatically, with far less than 100 now surviving in the wild.

Experts predict that the white-fin dolphin will become extinct in about 20 years if effective measures are not taken immediately.

The white-fin dolphin, or lipotes vexillifer, is a rare aquatic mammal only found in the Yangtze River. As early as 2,000 years ago, ancient Chinese documents gave accurate descriptions of these mammals.

However, the habitat of this dolphin has deteriorated constantly in recent years due to serious pollution, changes in the ecological environment, busy waterways, and rampant illegal fishing.

Statistics from the Fishery Bureau of the Ministry of Agriculture show that in 1984 white-fin dolphins numbered about 400, but diminished to 300 and 200 by 1986 and 1990.

Beginning in 1997, the bureau began to monitor the mammal every November along the 1900-km-long middle and lower reaches of the Yangtze, starting at the Gezhou Dam in central Hubei Province to Wusongkou at Shanghai.

During this year's monitoring, more than 20 ships from five provinces and Shanghai were sent out, but only five white-fin dolphins were found, compared with seven in 1998 and 21 in 1997.

Li Jianhua, vice-director of the bureau, said that related research institutions are currently analyzing the results of the three-year monitoring, which will provide a scientific basis for the bureau to take further action to rescue the endangered species. (Xinhua)