One of the most extensive coral reefs in the world was discovered by a UN-supported scientific mission off the coast of Tahiti. UNESCO said the divers ended up exploring large rose-shaped corals spanning over three kilometers at depths of between 30 and 65 meters.

Early indications suggest that the depth of the coral reef is what was able to protect it from bleaching caused by global warming.

"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 who also led the diving mission.

The reef find is incredibly unusual because of its deep location, especially because most of the world's coral reefs descend to 25 meters, if not less.

The rose-like corals are two meters in diameter, and the reef is around 30 meters and 65 meters wide.

"This discovery suggests that there are many more large reefs out there, at depths of more than 30 meters, in what is known as the ocean's 'twilight zone, which we simply do not know about," said UNESCO, the UN scientific, educational and cultural organization.

Finding coral reefs of this magnitude is significant because they're such an important food source for other organisms, and they can also aid research around biodiversity. In terms of sustainability, reefs can also provide protection from coastal erosion, including tsunamis.

"The discovery of this reef in such a pristine condition is good news and can inspire future conservation. We think that deeper reefs may be better protected from global warming," said Dr. Laetitia Hedouin from France’s National Centre of Scientific Research who was present on the mission.

Very few scientists have had the ability to investigate and study coral reefs at depths of more than 30 meters. However, recent advances in technology are making longer dives at these depths possible.

The team was able to carry out dives totaling around 200 hours to study the reef, and they witnessed coral spawning. Additional dives are planned to continue investigations around the reef.