Coral reefs around the Indian Ocean and Southeast Asia are dying at rates that may be the worst ever recorded, scientists said this week. Death rates as high as 80% have been recorded for some species, according to the study performed by the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
“It is certainly the worst coral die-off we have seen since 1998. It may prove to be the worst such event known to science,” said Andrew Baird, a principal research fellow for James Cook University in Australia.
The coral bleaching extends from the Seychelles in the middle of the Indian Ocean to the Philippines in Southeast Asia and encompasses much of the Coral Triangle, an area scientists refer to as the “Amazon rainforest of the seas” or the most diverse marine ecosystem on Earth.
A mass of abnormally hot water which moved into the Indian Ocean several months ago is behind the bleaching, according to the ARC report. The hot water caused the corals to shed microscopic algae which help nourish them. The algae also give color to the corals, so when the algae are gone, the corals starve and appear white or bleached. Dive operators reported water temperatures were 4 degrees Centigrade higher than average during the die-off, according to the ARC report.
Baird blamed “human-induced global warming” for the decline of the corals and said action must be taken to reduce carbon emissions that help retain heat in the atmosphere.