Scientists have discovered a pristine 3-km long reef of giant rose-shaped corals off the coast of Tahiti, in waters thought to be deep enough to protect it from the bleaching effects of warming ocean waters.
The reef, which lies at depths of more than 30 metres, likely took around 25 years to grow. Some of the rose-shaped corals measure more than 2 metres in diameter.
“It’s quite impressive to find such system in a very good state of health at that sort of depth,” said Julian Barbiere, marine policy head of UNESCO, who supported the expedition.
Most of the world’s known coral reefs lie in depths of up to 25 metres. However, the reef off the shores of Tahiti lies in the ‘Twilight zone’ of depths between 30 and 120 metres where there is still enough light for coral to grow and reproduce.
The find suggests there may be many more unknown large reefs in our oceans, with only 20% of the entire seabed mapped.
“It also raises the issue of how coral reefs become more resilient to climate change,” Barbiere told Reuters.
He underscored the need to map more of the ocean floor to better safeguard marine biodiversity.
A sign of a healthy marine ecosystem, coral reefs protect against the impact of storms and tsunamis, and some species are used in developing medicines.