Warmest oceans in history drive mass bleaching of world's corals

More than 60 percent of the world's corals have been damaged in a mass bleaching event that began last year and continues to unfold into the northern summer.

Bleaching caused by heat stress is a major health threat to coral reefs, nicknamed the rainforests of the sea because of their intricate ecosystems that host a wide variety of marine life.

"Crazy haywire" ocean temperatures – in the words of Derek Manzello, of the US National Oceanic and Atmospheric Administration – have triggered the fourth global mass coral bleaching event in memory.

"This event is still growing in size and impacts," Manzello told journalists. "I'm very worried about the state of the world's coral reefs. We’re seeing [ocean temperatures] play out right now that are very extreme in nature."

Data from the EU's Copernicus Climate Change Service shows that sea surface temperatures have been at record highs for the past 13 months.

Fuelling the extreme temperatures is the naturally occurring El Nino weather pattern, as well as energy trapped in the atmosphere and the oceans by greenhouse gases.

Visual proof of trauma

The ongoing mass coral bleaching is the world's fourth on record, with three others occurring between 1998 to 2017.

Read more on RFI English

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