Distribution and conservation of the Indo-Pacific humpback dolphin in China.

The Indo-Pacific humpback dolphin (Sousa chinensis Osbeck, 1765) is a threatened species inhabiting the waters of China. Despite being of conservation concern, the distribution and abundance of this species has not been comprehensively evaluated. From 1994 to 2008 we performed over 14 000 km of line-transect surveys and administered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo-Pacific humpback dolphins along the southern and eastern coasts of China. Through our study we were able to establish a reporting network of stranding and incidental catches for this species. Our quantitative data suggests that only 76 animals remain around Xiamen, 39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River. Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou. We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration, including underwater blasting, vessel collision, fishing, aquaculture and water pollution. Although some protected areas have been established and this species is protected under Chinese law, there remains virtually no protection for this animal.