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New Dolphin Found in Australia
Date : 07/07/2005
A colorful new species of Australian dolphin with a stubby dorsal fin and a big, round snout has just been identified, according to an international team of U.S. and Australian scientists.
Called the Australian Snubfin Dolphin, Orcaella heinsohni, the new species hails from the shallow coastal waters of north and northwest Australia.
For years it has been swimming there right under the noses of divers and marine biologists, all of whom thought it was another type of dolphin, the Irrawaddy, which it somewhat resembles.
Genetics proved them wrong.
"We found 16 fixed base pair differences between the Irrawaddy and the new Australian dolphin," said Kelly Robertson, who led the DNA study. "It is pretty exciting. The genetic differences seem clear cut and are even greater than those found between bottlenose and common dolphins."
Robertson, a scientist at the NOAA Southwest Fisheries Science Center in La Jolla, Calif., explained that genetic differences either are fixed or show some degree of variance.
If enough permanent changes to DNA are detected, as for this study, it usually means that the animals fall within different species.
The findings are published in the journal of Marine Mammal Science.
Skeleton and observational analysis conducted by James Cook University researchers Isabel Beasley and Peter Arnold also determined that the new dolphin has a shorter dorsal fin than the Irrawaddy and variations in a groove next to the fin.
The Snubfin dolphin additionally comes in shades of dark brown and white, as opposed to Irrawaddy's basic dolphin gray.
This latest Aussie native means that Australia now has 44 native whale and dolphin species. The other dolphins include such species as the Dusky, the Hourglass and the Pantropical Spotted Dolphin.
Most of Australia's dolphin population is under threat from humans, and the Australian Snubfin, with a population now of only about 1,000, is no exception.
It is shy of boats and people, but still often falls victim to human threats.
"Unfortunately, because they live in these environments, they are susceptible to many human threats including accidental catch in shark and fishing nets as well as effects of coastal development," said Beasley, lead author of the journal paper.
"Human threats on Irrawaddy dolphins in Southeast Asia are even more severe," said Beasley. "Five Southeast Asian dolphin populations were recently classified as 'Critically Endangered' by the World Conservation Union. This means the total population is less than 50 individuals, so there is a high chance of local extinction in the near future."
Since population numbers are used to determine conservation efforts and funding, Robertson hopes the discovery of the new species will strengthen work to protect both the Irrawaddy and the Australian Snubfin.
The World Wildlife Fund in Washington, D.C. told Discovery News that their colleagues in Australia already are looking into the matter.
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Source: Discovery News