'Remarkable' giant coral reef found off Tahiti

Scientists have discovered a vast reef of "pristine" rose-shaped corals apparently unharmed by climate change in deep water off the coast of Tahiti, UNESCO announced Thursday. 

Mapping approximately three kilometres (two miles) long and up to 65 metres (213 feet) wide, UNESCO said it was "one of the most extensive healthy coral reefs on record".

The UN heritage agency said it was "highly unusual" to find healthy coral in cooler waters between 30 and 65 metres deep and that it could suggest that there are more reefs in the ocean depth that are safer from the impacts of warming waters.

The discovery was made in November by divers with special equipment that allowed them to go deeper and spend 200 hours at the reef.

"It was magical to witness giant, beautiful rose corals which stretch for as far as the eye can see. It was like a work of art," said Alexis Rosenfeld, a French photographer and founder of the UNESCO partner 1 Ocean campaign.

The giant rose-shaped corals are each up to two metres in diameter.

"To date, we know the surface of the moon better than the deep ocean," said UNESCO Director-General Audrey Azoulay, adding that only 20 percent of the world's seabed has been mapped.

"The discovery of this reef in such a pristine condition is good news and can inspire future conservation," said Laetitia Hedouin, a marine biologist at French research agency (CNRS).

"We think that deeper reefs may be better protected from global warming."