Global coral reefs face risk of irreversible decline, report warns

Coral reefs are being hit by bleaching events so often that many no longer have enough time to recover, scientists warned in a report from the Global Coral Reef Monitoring Network.

Reefs cover less than 1 percent of the ocean, yet they support more than a quarter of marine life. Their condition also serves as an indicator of the health of the world’s oceans. The monitoring network said global coral cover has fallen well below normal levels and could enter irreversible decline.

Manuel Gonzalez Rivero, the report’s lead author and a scientist at the Australian Institute of Marine Science, said corals can recover if cooler conditions last long enough. But that recovery time is increasingly unavailable. He said the frequency of bleaching events has “pretty much doubled.”

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If we give them enough time, they have the capacity to recover. But we haven’t seen that amount of time being allowed. In fact, the frequency of those bleaching events has pretty much doubled.

Bleaching happens when corals expel the colorful algae living in their tissues. The loss of algae leaves them vulnerable to starvation and disease, although bleached corals are not necessarily dead. They need time in cooler water to recover.

Gonzalez Rivero said coral cover had remained relatively stable for about 40 years until 2010, followed by a steep change. The bleaching recorded in 2023 was the most extensive on record, affecting 77 percent of coral reef areas worldwide. He warned that another event is very likely this year as global temperatures remain elevated.

The warning came as organizers of the Pacific Islands Forum said at least five leaders from the 18-member group would miss its summit. The forum has long been presented as a symbol of regional unity and a venue for discussing climate change and ocean health.

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We had 40 years of coral cover around the world that had remained relatively unchanged until 2010. Since 2010, there has been a very steep change.