19 September 2008

Australia has 100 new shark and ray species

These creatures had character: "They do have a puppy-like feel".Australia has 300 species or sharks and rays, about half of which are only found in Australia. "With the exception of Indonesia, Australia has the richest shark and ray fauna on the planet." According to Peter Last, a taxonomist with the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

How were so many species 'suddenly' discovered?
The finding that Australia had many more species than thought owes much to revolutionary molecular identification techniques. DNA identification such as is used in the international Barcode of Life project sets a global standard.

Does it make a difference knowing what kind of shark it is?
Cataloguing of the new species was critical for the management of sharks and rays, which reproduce slowly and are vulnerable to overfishing.

For some species, identification will help ensure survival.

The southern dogfish, a blunt, metre-long shark, lives on a narrow band of heavily trawled continental shelf slope off south-east Australia. With an estimated 99% cut in its numbers over 20 years, it was recently listed as critically endangered.

The dark waters of Port Davey and Macquarie Harbour in south-west Tasmania provide the only known habitat for the modest, dinner-plate sized maugean ray. With warming seas under climate change, this habitat is threatened, Dr Last said. "This ray really hasn't changed much in 80 million years. It would be catastrophic to see it just go in the blink of an eye."

Why should we bother studying sharks?
Sharks and rays as apex predators play a vital role in the ocean's ecosystem and can be indicators of climate change. "Their populations are sensitive to small-scale events and can be an indicator of environmental change"

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