Melbourne: Scientists mapping the Great Barrier Reef in Australia have discovered the deepest corals yet, 125 metres below the ocean`s surface where waters are as dark as night.
The remarkable finding of a community of reef corals at depths previously thought to be impossible was made on the outer edge of the Ribbon Reefs to the north of the Barrier Reef.
The groundbreaking scientific expedition has found further evidence that corals are more resilient and widespread than previously thought.
Pristine corals have been found deep below the surface in areas where surface reefs have been badly damaged.
The use of remotely operated vehicles has opened up a new world of coral exploration. The Catlin survey has looked at 30 coral reefs along the 2300 km Great Barrier Reef.
"The discovery shows that there are coral communities on the Great Barrier Reef existing at considerably greater depths than we could ever have imagined," said Pim Bongaerts from the Global Change Institute at the University of Queensland.
"Most important of all, these discoveries show just how little we really know about the Reef and how much more is yet to be discovered.
"When we began our survey, we were amazed to see significant coral communities at depths of around 60m. However, it is truly mind-blowing to see reef coral at more than twice that depth and four times deeper than most scuba divers can reach," said Bongaerts.
The plating Leptoseris corals were found at a depth of 125m.
The Catlin Seaview Survey supports the collection of scientific data so experts can better understand climate change and its risks.
The Great Barrier Reef expedition is part of a program to survey many of the world`s coral reefs, which are under threat from climate change through warming oceans, acidification of seawater, coastal pollution and unsustainable fishing practices, the report said.
The deep coral discovery was possible due to very calm weather, Dr Paul MuirMuir, a taxonomist from the Museum of Tropical Queensland and team member, said.
Scientists were able to deploy the robot on the very front of the Ribbon Reefs, an area usually too dangerous to anchor.