A massive, unspoiled reef of giant rose-shaped corals has been discovered off the coast of Tahiti apparently unharmed by the bleaching effects of the ocean warming due to climate change, UNESCO announced Thursday. The reef is approximately 3 kilometers (1.8 miles) long and up to 65 meters (213 feet) wide, and “one of the most extensive healthy coral reefs on record,” said the UN agency.
The UNESCO called the discovery to be “highly unusual,” to find healthy coral in cooler waters between 30 and 65 meters deep and that it could suggest that there are more reefs in that ocean depth range 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. Temperature sensors have been placed in the area as part of a programme to analyse why the corals appear to be unaffected by climate change and monitor its population dynamics.
Alexis Rosenfeld, a French photographer and founder of the UNESCO partner 1 Ocean campaign, called the reef “a work of art.” “It was magical to witness giant, beautiful rose corals that stretch for as far as the eye can see,” Rosenfeld added.
The giant rose-shaped corals are each up to 2 meters 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% 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), adding, “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, with no signs of stress or disease. 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 also eat corals.