They live in a dark and mysterious wilderness of thick sea grasses and coral gardens that are teeming with creatures never seen before – huge worms, giant prawns and massive, creepy crabs.
Many of the marine animals hauled to the surface and landed on the decks of the research ship Aurora Australis have never been seen before and will now be sent to universities and museums around the world so their relationship to other known creatures can be assessed.
Tissue sampling and DNA will be used in the tests, but voyage leader Martin Riddle said when he arrived back in Hobart, Tasmania, yesterday that he believed much of his catch would be totally new species.
"With us we had some of the world's experts on Antarctic fish and they were completely, completely flabbergasted at the sight of some of the fish that came on board – they were unable to name them," said Dr Riddle after the census of the South Pole's marine life.
"The fish had fins in various places. They had funny, dangly bits around their mouths.
"Many of them had very large eyes, although what they are going to use them for where this is no light I couldn't tell you. But they are very strange-looking fish."
In some places, he said "every inch of the sea floor is covered in life".
Giantism, he said, was "very common in Antarctic waters", where his team had even found deep gouges in the sea floor, caused by icebergs scraping the coral" as they floated by.
"Some of the video footage we have collected is really stunning – it's amazing to be able to navigate undersea mountains and valleys and actually see what the animals look like in their undisturbed state."
The scientific team used three ships to trawl for life in 30,000 square miles off the east of the Antarctic continent.
Dr Riddle said he and his team made the voyage "with certain expectations" but they were totally exceeded.
"What we found just blew me away and made me realise just how really important it is to document all this before the changes that we're seeing take effect, ocean acidification among them."
This toxic destruction, he said, was brought about by global warming which came from increasing carbon dioxide levels in the atmosphere.
"This is a real threat to some of these marine creatures."
An Australian scientist who was travelling on an accompanying Japanese research ship, Dr Graham Hosie, said his team had discovered totally new species of plankton and jellyfish.
Although the jellyfish looked much like the species found around most coastlines of the world, the Antarctic variety had tentacles that stretched up to 18ft.
His team had also found glass-like creatures called tunicates, unidentifiable fish, starfish and sea urchins.
The scientists estimate that at least a quarter of the sea life – weighing up to 65lbs - they have brought to the surface has been previously unknown.
They believe the census, known as the Collaborative East Antarctic Marine Census – made up of researchers from France, Japan and Australia – will help scientists understand how marine communities have adapted to the unique, unspoiled Antarctic environment.
Marine scientists have already suspected that huge creatures live in the very deep waters of the Southern Ocean which reaches Antarctica.
Giant squid have been caught by New Zealand fishermen, but these are usually sick creatures which have risen up from the sea bed.
