Tuesday, July 05, 2005

ENV: Australian Snubfin Dolphin

Whoa, a new species of mammal in the 21st century, and not just any mammal, but a cetacean!






Second photo by the discoverer George Heinsohn


Most impressive . . .

New Species of Australian Dolphin
By Nick Squires, 06.07.05, The New Zealand Herald

SYDNEY - A new species of dolphin has been found living in the warm tropical waters of northern Australia. Scientists had always thought the dolphins were a local variation of the Irrawaddy dolphin, a species which ranges into Southeast Asia. But marine biologists have found enough differences in the population to declare it a separate species, the Australian snubfin dolphin. It derives its name from its short, stubby dorsal fin. Identifying a new species is a rare event in the cetacean world and researchers from James Cook University and the Museum of Tropical Queensland, both in Townsville, are celebrating the find. "There are clear differences between the two populations that had not been previously recognised and these were confirmed by the studies on DNA," said Isabel Beasley, a PhD student and research team member. The dolphins, mostly found in shallow coastal waters, are susceptible to being caught in fishing and anti-shark nets. Coastal development may also affect their health. Scientists have no idea how numerous they are - around 200 are believed to live in the ocean off Townsville, northern Queensland, and there is an unknown number living in the rest of the species' range, which extends to Western Australia. "Even though Australia is a developed country ... more is known about the Mekong River dolphin population in Cambodia than the Australian species," said Peter Arnold, of the Museum of Tropical Queensland. They have been given the Latin name Orcaella heinsohni, after George Heinsohn, a researcher who studied dolphins in the 1970s.


New dolphin species discovered off Australia
Last Updated Tue, 05 Jul 2005 14:18:14 EDT, CBC News

A new breed of dolphin has been identified in Australia, genetic testing has confirmed.
The Australian snubfin dolphin (Orcaella heinsohni) has a distinctive stubby dorsal fin and rounded nose. It swims in shallow waters off Australia's northern coast.

Scientists had thought the snubfin was a related species called the Irrawaddy dolphin (Orcaella brevirostris), which is found in Australia and in Asian rivers.

Isabel Beasley, a doctoral candidate at James Cook University, suspected the snubfins were a distinct species after she noticed size and colour differences between the Asian and Australian populations.

Snubfins are tri-coloured dolphins ranging from dark brown to white; the Irrawaddy is slate grey with a white belly, Beasley said.

To back up the new species designation, Beasley and Peter Arnold, a curator at the Museum of Tropical Queensland watched both types of dolphins at sea. They also examined the dolphins' skulls and measured the mammals.

The pair sent DNA samples to the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center in La Jolla, Calif., which confirmed snubfin's separate status as a species.

"Given that the Australian snubfin dolphin appears to be restricted to Australian, and possibly Papua New Guinea waters, Australia now has significant national and international obligations to research and conserve remaining populations," Arnold said in a statement.

The researchers said they reported the discovery in the Marine Mammal Science Journal in the hopes of helping to save the dolphins.

The scientific name of the new species honours Australian researcher George Heinsohn. His studies on stranded dolphin carcasses in the 1960s and 1970s contributed to the new species designation, the pair said.


Australia claims new dolphin species
The World Today - Tuesday, 5 July , 2005 12:50:00, Reporter: Karen Barlow

TANYA NOLAN: It was thought to be just another regular visitor from Asia that liked the shallow waters of the Great Barrier Reef. But the rare and strange looking dolphin has in fact been declared a new Australian species.Queensland and Californian scientists have confirmed with DNA profiles and skull measurements, that the short stubby dorsal fin and round bulbous head belong to the newly-named Australian Snubfin dolphin.

Karen Barlow reports

KAREN BARLOW: The clear, shallow water surrounding the Great Barrier Reef is a dolphin haven. And it's long been thought that it was attracting peculiar dolphins from South East Asia known as the Irrawaddy.But some marine researchers suspected something different about the dolphins frolicking in the waters off Townsville.James Cook University's Isabel Beasley.

ISABEL BEASLEY: When you look at it, it has three colours, it's dark on the top and then it has a lighter kind of brown on the middle and a white belly. They have a rounded forehead, which is very unlike other dolphin species in Australia, and also it has a very small dorsel fin, snub fin dorsel fin, which is where its name actually comes from.

KAREN BARLOW: Is it reminiscent of a dugong more than a classic dolphin?

ISABEL BEASLEY: That's probably quite correct actually. The way that its forehead is shaped, it's very rounded, and many people do confuse the two, but it is that small little dorsel fin on that back of its body, how you can distinguish it.

KAREN BARLOW: Is it a showy or shy dolphin?

ISABEL BEASLEY: Oh it's very unlike the classic bottlenose or other species that you get. It's a very shy dolphin, it tends to keep away from boats.

KAREN BARLOW: Since 1996, Isabel Beasley has been studying the Asian Irriwaddy dolphin. That species is in trouble. Khmer Rouge guerrillas hunted Irrawaddy in the Mekong River in the early 1970s and they're still considered in the area to be a delicacy. Three years ago, Ms Beasley was invited into Townsville-area dolphin investigations.

ISABEL BEASLEY: I met a man at the Museum at tropical Queensland, Dr Peter Arnold, and him and a man called George Heinsohn who also worked at James Cook University, they'd been actually also studying this population since about the 1960s or 1970s. They'd written a paper in 1996 where they had come to the conclusion that there may be differences, so we worked together from that point on, Peter Arnold, myself and George Heinsohn, and that's when we came to the conclusion that there were so many different characters that there was potential for species level differences.

KAREN BARLOW: With subtle physical differences between the Asian and Australian dolphins confirmed, Isabel Beasley it was left to DNA profiling to settle the matter.

ISABEL BEASLEY: A new species of mammal occurs very, very rarely. In terms of dolphins, the last dolphin species was discovered back in 1956, I think that was the Frasers dolphin that was discovered in Borneo

KAREN BARLOW: So it's quite a breakthrough for the area?

ISABEL BEASLEY: Exactly. Yeah. There's not many countries in the world that actually have their own particular species, and although it looks like it may occur that the Australian Snubfin might also occur in Papua New Guinea waters, the majority of the population occurs in Australia. So it's, yeah, extremely important in terms of conservation and management that Australia now focuses very strongly on this new species.

ISABEL BEASLEY: Not much is known about Australian Snubfin dolphin numbers, but around 200 have been observed in the Townsville area. Like other dolphins they are susceptible to shark nets, coastal development and harassment from fishing and tourist boats.

TANYA NOLAN: Karen Barlow on the permanent resident we didn't know we had.

0 Comments:

Post a Comment

<< Home