Distribution and abundance of Chinese white dolphins (Sousa chinensis)in Xiamen

During 1994～1999,84 vessel surveys were conducted with having a photos taken,and 392 individuals were recorded.At the same time,totally 20 observation sites were established,and the record for 239 months amounted to 12 624 individuals.Chinese white dolphins occur all around Xiamen waters of 700 km²,and they may swim upstream to the Jiulong River but never swim out of Jinmen Island and Wuyu Isle.Generaly,the dolphina are sighted very close to the shore and most frequently occur in areas included west harbour of Xiamen and the mouth of Tong'an Bay.The frequency when the dolphins jumped out of the water varies with season,which is the highest in April to May.According to surveys and supplementary surveys,nearly 60 individuals are estimated in Xiamen waters,and only 40 individuals are distinctively recorded through having a photos taken.Now the population has the tendency to decrease,so in-situ and off-situ measures should be both employed to emphasize the conservation of Chinese white dolphins,the first-class protected species in China.