Worst Coral Bleaching Hits 84% Of The World's Reefs

An unprecedented coral bleaching episode has spread to 84 percent of the world's reefs in an unfolding human-caused crisis that could kill off swathes of the essential ecosystems, scientists warned Wednesday.

Since it began in early 2023, the global coral bleaching event has mushroomed into the biggest and most intense on record, with reefs across the Pacific, Indian and Atlantic oceans affected.

Coral turns ghostly white under heat stress and the world's oceans have warmed over the last two years to historic highs, driven by humanity's release of planet-warming greenhouse gases.

Reefs can rebound from the trauma but scientists told AFP the window for recovery was getting shorter as ocean temperatures remained higher for longer.

Conditions in some regions were extreme enough to "lead to multi-species or near complete mortality on a coral reef", said the US National Oceanic and Atmospheric Administration (NOAA).

This latest episode was so severe and lasting that even more resilient coral was succumbing, said Melanie McField from the Healthy Reefs for Healthy People initiative, which specialises in the Caribbean.

"If you continue to have heatwave after heatwave, it's hard to see how that recovery is going to happen," the veteran reef scientist told AFP from Florida.

Bleaching occurs when coral expels algae that provides not just their characteristic colour but food and nutrients, leaving them exposed to disease and possibly eventually death.

Live coral cover has halved since the 1950s due to climate change and environmental damage, the International Coral Reef Initiative, a global conservation partnership, said in a statement Wednesday.

Scientists forecast that at 1.5C of warming, some 70 to 90 percent of the world's coral reefs could disappear – a disastrous prospect for people and the planet.

Coral reefs support not just marine life but hundreds of millions of people living in coastal communities around the world by providing food, protection from storms, and livelihoods through fishing and tourism.

- FRANCE 24 with AFP