WEST COAST ALIVE WITH UNIQUE SHARKS
21st September 2008, 6:00 WST
Scientists have identified 46 new species of sharks in WA, 24 of which are thought to exist nowhere else.
The CSIRO’s 18-month project was to classify new sharks found in Australian waters.
Fish expert William White said a fascinating find was a one-of-a-kind carpet shark, found in the stomach of a school shark near Chatham Island, off Walpole.
While it was found almost 20 years ago, scientists were unable to state definitively whether it was a unique species, Dr White said.
“This one was a lot more elongated, it had a real ‘snake’ look,” he said.
“Even though it was obviously a new species, when you’ve got something that has come out of a gut of a shark, it’s lost colour and has had quite a few bite marks.
“The reason it took so long to classify was that we assumed we’d find other specimens and we never did.”
WA had also proved to have a fascinating array of unique Wobbegong sharks. “It’s almost like Western Australia was the centre of biodiversity for that group,” Dr White said. “There’s not many species known worldwide — only about 10 — but six or seven of them occur in Western Australia. “There’s been four new species described in Western Australia in the last couple of years.” Analysis of DNA sequences was used to differentiate closely related species of sharks, some of which scientists had thought were the same as those found outside Australia.
Other new species included the northern freshwater whipray and northern river shark, which are found in the top half of Australia.
Dr White said whiprays and northern river sharks could grow up to two metres long and were found in the Fitzroy River.
“It was originally thought to be a species which occurs throughout Asia, but it’s been found to be a separate species which is endemic to Australia,” Dr White said.
The new classifications would help manage marine ecosystems.
Hundred New Sharks and Rays Classified
September 18th, 2008
Australian scientists have completed an ambitious 18-month project to name and describe more than 100 new species of sharks and rays. Conducted by scientists working under the auspices of CSIRO's Wealth From Oceans National Research Flagship, the project named a third of Australia's - and about a tenth of the world's - shark and ray species.
Team leader, CSIRO's Dr Peter Last, says analysis of DNA sequences was used to clarify the identity of closely related species.
'Additional taxonomic information like this is critical to managing sharks and rays, which reproduce relatively slowly and are extremely vulnerable to over-fishing and other human impacts,' he says. 'Their populations are also sensitive to small-scale events and can be an indicator of environmental change.'
CSIRO's Dr William White says sharks and rays also play a vital ecosystem role as apex predators. 'Take them away and what does it mean for the rest of the ecosystem?' Dr White says. 'We can't understand possible implications unless we know what species we're dealing with.'
The new species include:
The endemic, Northern Freshwater Whipray and the Northern River Shark, which grow to over two metres in length, and are among the largest freshwater animals in Australia. Until recently these were confused with similar marine species.
The Endangered Maugean Skate which has an extremely narrow distribution. It is closely related Gondwanan ancestor which lived off southern Australia some 80 million years ago, and the present day species clings to life at the south-western tip of Tasmania.
A Critically Endangered gulper shark, the Southern Dogfish, which is endemic to the continental slope off southern Australia. It has suffered severe population declines in the past few decades.
More than 90 of the new species were identified but undescribed in the 1994 book; Sharks and Rays of Australia, by Dr Last and CSIRO's Dr John Stevens. The new names and descriptions will feature in a revised edition of the book in 2009. Specimens of many of the new species are in the Australian National Fish Collection at CSIRO Hobart - the largest collection of preserved sharks and rays in the Southern Hemisphere.
A workshop focusing on the project's findings will be held at Sydney's Australian Museum on 22 September during the 2nd Annual Meeting of the Oceania Chondrichthyan Society. Involving some of the world's leading experts in the field, the WWF-Australia-sponsored workshop also will assess priority areas of future research and management of sharks in Australian waters.