Australian snubfin dolphin
Until 2005, the Australian snubfin dolphin was thought to be an isolated population of the Irrawaddy dolphin (Orcaella brevirostris), however it is now recognised as a separate species. It has not been studied extensively throughout its range and no overall population estimate exists although numbers are considered to be in the low thousands.
Similar in appearance to its close relative the Irrawaddy dolphin, the Australian snubfin dolphin is a robust dolphin with a round melon and almost no beak, which gives its head a blunt appearance. A neck crease may be visible behind the head. It has a small triangular or falcate dorsal fin, giving it its name of snubfin, and large spatulate flippers with rounded tips. The flukes are relatively small with pointed tips. Colouration of the Australian snubfin dolphin runs from slate to blue-grey. There is generally a darker cape on the dorsal side of the dolphin, with a lighter band of grey or brownish-grey on the side, and the belly is a lighter almost whitish grey. Calves are born a somewhat darker and more uniform grey and lighten with age.
Australian snubfin dolphins are shy creatures, not known to bow-ride. They are found in small groups and when startled may dive for long periods. Sometimes they will spyhop, lobtail and roll sideways waving their flippers and when in groups they may perform low playful leaps with a great deal of splashing. They prefer shallow coastal waters and brackish estuaries, generally less than 10m deep. They congregate around river and creek mouths and are often found in the same areas as the Indo-Pacific humpback dolphin, which can at times be seen chasing it aggressively.
The Australian snubfin dolphin can be found on the north and eastern coasts of Australia, and up to the coast of Papua New Guinea. Its preference for coastal waters makes it vulnerable to human interference, though to date most of its habitat has not been severely degraded. Currently, the biggest threat to this species is bycatch in shark nets designed to protect swimming areas, as well as in gillnets set across rivers for barramundi and salmon. It is also at serious risk from habitat modification and coastal development and the creation of several marine parks in northern Australia are intended to help protect the species. In 2008 the Australian snubfin dolphin was listed as Near Threatened by the IUCN Red List.