Remarkable’ giant coral reef found off Tahiti

PARIS

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 on Jan. 21.

Mapping approximately three kilometers (two miles) long and up to 65 meters (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.”

Most of the world’s known reefs have been found at depths of up to 25 meters and the UN heritage body said the Tahiti reef could suggest there are more areas of healthy coral in the ocean’s unmapped “twilight zone.”

“This remarkable discovery in Tahiti demonstrates the incredible work of scientists who, with the support of UNESCO, further the extent of our knowledge about what lies beneath,” said Azoulay.

French Polynesia suffered a significant bleaching event back in 2019, but this newly discovered reef does not appear to have been significantly affected.

“These corals do not show signs of stress or disease,” Hedouin told AFP.

Bleaching occurs when healthy corals become stressed by spikes in ocean temperatures, causing them to expel algae living in their tissues, leaving graveyards of bleached skeletons where vibrant ecosystems once thrived. Starfish can also ravage corals by eating them.