First record of the Indo-Pacific humpback dolphins (Sousa chinensis) southwest of Hainan Island, China

Abstract

Background: Populations of Indo-Pacific humpback dolphins (Sousa chinensis) in China were known to be distributed from the Beibu Gulf near the border with Vietnam to the mouth of the Yangtze River. According to existing studies, the waters around Hainan Island, China, were not considered to be part of the humpback dolphins' distribution. Results: In 2014, for the first time, we recorded humpback dolphins in waters southwest of Hainan Island. Conclusions: This record expands the known southern distribution range of this dolphin in Chinese waters by more than 300 km.