Aussie researchers discover Indian Ocean 'shark graveyard'

Researchers from Australia's national science agency have discovered a shark graveyard on the floor of the Indian Ocean.

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) on Wednesday revealed some of the finds by researchers conducting biodiversity surveys of two of the country's newest marine parks on board the research vessel (RV) Investigator.

While exploring marine life and seabed habitats in the Cocos Islands Marine Park in the remote Indian Ocean, a trawl at a depth of 5,400 meters brought up more than 750 fossilized shark teeth.

The teeth belonged to not only modern sharks, including mako and white sharks, but also prehistoric species such as an ancestor of the megalodon - a giant species that died out approximately 3.5 million years ago.

Researchers described the discovery as an astounding find.

Following the surveys of the Cocos Islands, the RV Investigator is now in the Gascoyne Marine Park closer to the coast of Western Australia (WA).

John Keesing, chief scientist on the voyage from the CSIRO, estimated that one third of the species collected on the voyages are new to science.

They include a new species of horn shark that lives in waters deeper than 150 meters and has never been described or named.

"The discoveries we make aren't just limited to new species. These voyages give us the opportunity to learn more about marine ecosystems, as well as species range, abundance and behaviour," Keesing said in a media release.

"From small, new, bottom-dwelling sharks, to massive ancient mega-sharks that once roamed the oceans, these biodiversity surveys give us vital insights into the life in our oceans."

The CSIRO is conducting the surveys on behalf of Parks Australia in order to boost understanding of the marine parks and aid conservation efforts.