Coral reefs facing irreversible decline due to frequent bleaching, scientists warn

Coral reefs are experiencing bleaching events so frequently that they no longer have time to recover before the next one strikes, scientists have warned.

Global coral cover is now well below normal levels and at risk of irreversible decline, the Global Coral Reef Monitoring Network (GCRMN) said in a report released on Monday.

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

Bleaching occurs when corals expel the colourful algae living in their tissues. Without this algae, they become vulnerable to starvation and disease. Bleached coral are not dead, but they need time in cooler water to recover.

“We had 40 years of coral cover around the world that had remained relatively unchanged until 2010,” said Gonzalez Rivero, a scientist at the Australian Institute of Marine Science. “Since 2010, there has been a very steep change.”

The latest bleaching in 2023 was the most extensive on record, impacting 77 percent of the world’s coral reef areas.

Rivero warned that another such event is “very likely” this year given elevated temperatures globally.

Coral reefs are critical barometers for global ocean health, supporting more than 25 percent of all marine life despite covering less than 1 percent of the ocean floor.

The GCRMN’s warning came as organisers of the annual Pacific Islands Forum announced that at least five leaders of the 18-nation group will skip the group’s summit.

The forum has been touted for decades as a symbol of regional unity, and is used to discuss pressing matters facing Pacific states, including climate change and ocean health.