DNA tests identify new species of dolphin in Australia

A Southern Australian bottlenose dolphin in Spencer Gulf, South Australia (photo by Kerstin Bilgmann).

New dolphin species for Australia

November 2008. Marine mammal experts have uncovered a new species of dolphin in Australian waters, challenging existing knowledge about bottlenose dolphins and highlighting the country's marine biodiversity.

Dr Luciana Möller, of the Marine Mammal Research Group and the Molecular Ecology Lab at Macquarie University led a study that found that coastal bottlenose dolphins from southern Australia should in fact be classified as a new species rather than considered as one of the recognised bottlenose dolphin species.

Bottlenose dolphin species
There are currently two recognised species of bottlenose dolphins and both are found in Australian waters: the common bottlenose dolphin generally found in offshore waters in Australia and the Indo-Pacific bottlenose dolphin, found in coastal waters. Dr Möller said that it is difficult to distinguish some species of bottlenose dolphins using only external body features.

"The group to which bottlenose dolphins belong includes several species that have differentiated relatively recently in evolutionary time and therefore it is difficult to distinguish or understand relationships between them based on morphology alone," she said.

Endemic to Australia
The new coastal bottlenose dolphin will be the second dolphin species found only in Australia. Dr Möller says this discovery has important implications for the species and for marine science in general.

Dr Moller said "In the current biodiversity crisis, when we are losing so many animal species, it is very exciting to find out about these unique Australian dolphins. They should be given special conservation attention due to their limited distribution to coastal waters of southern Australia. Due to their coastal habitat, these dolphins are also more likely to face threats such as pollution, overfishing and entanglement in nets."

DNA analysis
Using DNA analysis, the researchers found that coastal bottlenose dolphins from southern Australia were more closely related to the Fraser's dolphin which is found mostly in deep waters of the Pacific and Indian Oceans. Dr Möller also said that her research team's findings demonstrated how important DNA studies are to uncovering hidden marine diversity.

"It suggests we still have a lot to learn about how many marine species are out there," she said.

The researchers, from Macquarie University and Monash University used genetic methods to identify a new dolphin species. Their findings were published this month in the journal Molecular Phylogenetics and Evolution.