After more than 10 years of scientific collaboration, researchers in Australia have found evidence that there are in fact four species of humpback dolphin as opposed to the previously considered two – although the idea of there being three species has long been considered.
The four species identified in the humpback (Sousa) genus are – the Atlantic humpback dolphin (Sousa tuezii) which is found in waters off West Africa, the Indo-Pacific humpback dolphin which ranges from the central to western Indian Ocean (it has long been believed but not proven until now, that this species is Sousa plumbea), another species of Indo-Pacific humpback dolphin (Sousa chinensis) which inhabits the eastern Indian and western Pacific Oceans and the fourth, this previously unknown Australian species that inhabits an area believed to be from the south of Queensland around northern Australia to Shark Bay in the west.
The authors of the report, published in the latest edition of Molecular Ecology, have called for an urgent re-evaluation of the species’ conservation status as this new discovery has major ramifications for the long-term survival of this and the other Indo-Pacific humpback dolphin species. (The Atlantic humpback dolphin was previously recognised as a seperate species and listed by the IUCN as Vulnerable in 2008). Prior to this discovery it was already considered that Indo-Pacific humpback dolphins were near threatened, and a further split into genetically distinct species will therefore undoubtedly mean even less individuals remain in each of the other species of Indo-Pacific humpback dolphins.