The Indo-Pacific Humpback Dolphin, Sousa chinensis (Osbeck, 1765), in Australian Waters: a Summary of current knowledge

Abstract

Indo-Pacific humpback dolphins (Sousa chinensis) occur in the coastal northern waters of Australia from approximately the Queensland – New South Wales border (31°27primeS, 152°55primeE) to Ningaloo Reef (22°17primeS, 113°48primeE) in Western Australia. Due to their coastal, estuarine distribution, Indo-Pacific humpback dolphins are particularly vulnerable to several human activities in and adjacent to coastal areas. At present, it is not possible to assess the population status of humpback dolphins in Australian waters because information on their biology and ecology is limited. The sparse data available for selected areas indicate that humpback dolphins occur in discrete, geographically localized populations and are susceptible to anthropogenic threats (e.g., incidental captures in gill nets). The conservation of humpback dolphins in Australia's northern coastline will depend on the maintenance of high-quality habitat in areas that are already under some protection, the identification of critical habitats, the inclusion of these habitats in the rezoning initiatives of protected areas, and the reduction of conservation threats. Precautionary measures should be adopted while further work on abundance estimates, population structure, and levels of human-caused mortality are carried out on a wider scale in Australian waters.