Australian scientists have discovered bizarre deep sea life hundreds of metres down in the seas around the Great Barrier Reef.

Ancient sharks, giant oil fish, swarms of crustaceans and a primitive shell-dwelling squid species called the nautilus were among the astonishing life captured by remote controlled cameras 1,400 metres below the surface at Osprey Reef, 350 kilometres north-east of Cairns.

Lead researcher Professor Justin Marshall, from the Queensland Brain Institute at the University of Queensland, says his team also found several unidentified fish species, including "prehistoric six-gilled sharks".

"Some of the creatures that we've seen we were sort of expecting, some of them we weren't expecting and some of them we haven't identified yet," he said.

"There was a shark that I really wasn't expecting, which was a false cat shark, which has a really odd dorsal fin."

The mission, known as the Deep Australia project and funded by the Australian Research Council, used special low-light sensitive cameras that were custom designed to trawl the ocean floor.

Professor Marshall says Osprey Reef is part of the Coral Sea Conservation Zone, which has been identified as an area of high conservation value.

He says it is therefore important we study the ecosystems and species that live in this area.

"We simply do not know what life is down there and our cameras can now record the behaviour and life in Australia's largest biosphere, the deep sea," he said.

Ancient nautilus

The researchers also collected footage of the nautilus, an ancient relative of the squid and octopus, which lives in a shell.

They measured the 'living fossils' to find out more about their biology before returning them to sea.

"Learning more about these creatures' primitive eyes and brain could help neuroscientists to better understand human vision," research student Andy Dunstan said.

Professor Marshall says most of our knowledge on how nerve cells function and communicate was first pioneered through work on giant squid nerve cells.

"We are now returning to these original model systems, both for their own intrinsic interest and also to better understand brain disorders which lead to conditions such as epilepsy," he said.

Under threat

Professor Marshall says the research had been made more urgent by recent oil spills affecting the world heritage-listed Great Barrier Reef, and the growing threat to its biodiversity by the warming and acidification of the world's oceans.

"One of the things that we're trying to do by looking at the life in the deep sea is discover what's there in the first place, before we wipe it out," he said.

"We simply do not know what life is down there, and our cameras can now record the behaviour and life in Australia's largest biosphere, the deep sea."

Scientists have already warned the 345,000-square kilometre attraction is in serious jeopardy, as global warming and chemical run-off threaten to kill marine species and cause disease outbreaks.

In April, the Chinese coal ship Shen Neng 1 gouged a scar in the reef when it ran aground whilst attempting to take a short cut, leaking tonnes of oil into a famed nature sanctuary and breeding site.

Professor Marshall says the cameras will now be sent to the sludge-ridden Gulf of Mexico to monitor the effects of the oil spill on marine life there.

- ABC/AFP