Reef Report for Monday, July 25, 2005
New Species of Dolphin Discovered on the Great Barrier Reef
A new species of dolphin that is found only on the Great Barrier Reef has been discovered and described this past month.
Dr. Isabel Beasley, a post-doctoral student at James Cook University in Townsville, Australia, announced the description of this new species, which they call the Australian Snubfin Dolphin, making it the first new species of dolphin discovered in over 50 years.
This dolphin species exists as a group of some 200 individuals found in the Townsville area. This is a very shy species, so almost nothing is known about itís distribution or ecology, but it is thought that it may be found along the Northern Great Barrier Reef, possibly as for north as New Guinea.
The existence of this group of dolphins has been known for since the 1960ís, but initially the species was thought to be an isolated population of the Irrawaddy Dolphin, an extremely rare species found in a very few rivers and lakes in New Guinea, India, Thailand, Cambodia and Laos.
In the 1960ís two Australian scientists Dr Peter Arnold, and George Heinsohn had began studies the anatomy of the Townsville dolphins, and in 1996 published a paper speculating that they may be a new species.
Dr. Beasely and Dr. Arnold began to follow up on this research, and did more detailed studies comparing the anatomy and behavior of these dolphins with the Irrawaddy River Dolphin. The large number of structural differences between the two populations led to a genetic study by Dr. Kelly Robertson, a researcher in the United States, that confirmed the significant unique gentetic differences of the Townsville poplulation. This new species is being called the Australian Snub-nosed Dolphin, and goes by the scientific name Orcaella heinsohni.
One of the prime motivations spurring their research is the extremely threatened status of the Irrawaddy Dolphin, as well as conservation concerns for the Snubfin Dolphin. With the Snubfin dolphin now split off from the Irrawaddy Dolphin, population estimates for the Asian species drop to less than 50 individuals in 5 widely separated populations, and itís conservation status was changed to critically endangered by the World Conservation Union. The effects of mining, gill net fishing, and human development in the river habitats of this species are thought to be the main causes of the dramatic reduction in their numbers.
With the additional publicity of this discovery, Dr.'s Arnold, and Beasely hope that the government of Australia will be encouraged to sponsor further research into the biology and conservation of both species, as well as make members of the public (like you!) aware of and involved in the conservation needs of these species.
James Cook University Press Release.
Conservation Status of the Irrawaddy Dolphin.
World Conservation Union database of endangered species. (Have a look, and letís hope it does not get any larger.)
World Dolphin and Cetacean Society.
The weekly reef report is written by Joel Groberg of DiveTheReef.com,
who compiles them from the many conversations he has with dive staff in the area, as well as† many other local sources in the dive
Index of all reef reports.