Earth's fourth global coral bleaching event is CONFIRMED

• Coral has turned white as the world’s fourth global bleaching event is confirmed
• The change is linked to climate change and rising ocean temperatures 

There’s nothing quite like seeing a myriad of fish dart in and out of brightly-coloured reefs.

But coral across the Atlantic, Pacific and Indian Oceans has turned white as the world’s fourth global bleaching event has been confirmed.

The change, caused by heat stress, is linked to climate change and rising ocean temperatures as well as low tides, pollution or too much sunlight.

And experts have warned that, unless there is a global effort to help the coral recover, it will turn black and die.

‘As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe,’ Derek Manzello, NOAA Coral Reef Watch coordinator, said.

There’s nothing quite like seeing a myriad of fish dart in and out of brightly-coloured reefs. But coral across the Atlantic, Pacific and Indian Oceans has turned white as the World’s fourth global bleaching event has been confirmed. Pictured: Coral bleaching in American Samoa

What is coral bleaching? 

Corals have a symbiotic relationship with a tiny marine algae called ‘zooxanthellae’ that live inside and nourish them.

When sea surface temperatures rise, corals expel the colourful algae.

The loss of the algae causes them to bleach and turn white.

This bleached states can last for up to six weeks, and while corals can recover if the temperature drops and the algae return, severely bleached corals die.

Healthy coral is coated with an algae-like substance called zooxanthellae, which they depend on to survive.

When coral becomes too stressed from changes in its environment, the coating can become toxic and leave the coral – turning it white and leaving it vulnerable to starvation, disease and death.

A report, published by the International Coral Reef Institute (ICRI), reveals that since 2023 there has been confirmation of mass bleaching of coral reefs in at least 53 countries, territories and local economies.

This includes Florida, the Caribbean, the Eastern Tropical Pacific including Mexico, El Salvador, Costa Rica, Panama, and Colombia, Australia’s Great Barrier Reef, large areas of the South Pacific including Fiji, Vanuatu, Tuvalu, Kiribati, and the Samoas, the Red Sea, the Persian Gulf and the Gulf of Aden.

Reports have also been confirmed of widespread bleaching across parts of the Western Indian Ocean, including Tanzania, Kenya, Mauritius, the Seychelles, Tromelin, Mayotte, and off the western coast of Indonesia. The monitoring of coral reefs is carried out by the National Oceanic and Atmospheric Administration (NOAA).

The change, caused by heat stress, is linked to climate change and rising ocean temperatures as well as low tides, pollution or too much sunlight. Pictured: coral bleaching on Heron Island, Great Barrier Reef

Experts have warned that, unless there is a global effort to help the coral recover, the coral will turn black and die. Pictured: Coral bleaching on the Great Barrier Reef

READ MORE: Great Barrier Reef ‘in grave danger’ as world could see worst bleaching event in history

Mr Manzello said: ‘From February 2023 to April 2024, significant coral bleaching has been documented in both the Northern and Southern hemispheres of each major ocean basin.

‘When these events are sufficiently severe or prolonged, they can cause coral mortality, which can negatively impact the goods and services coral reefs provide that people depend on for their livelihoods.’

Widespread coral death can impact livelihoods, food security and economies, including local tourism and the commercial fishing industry.

However, researchers said that it is important to remember that coral bleaching does not always lead to coral death.

Widespread coral death can impact livelihoods, food security and economies, including local tourism and the commercial fishing industry. Pictured: knobby cactus coral in the Virgin Islands in July 2023, November 2023, and March 2024

However, researchers said that it is important to remember that coral bleaching does not always lead to coral death. Pictured: large flower coral in the Virgin Islands in April 2022, November 2023, and March 2024

If the stress driving the bleaching diminishes, corals can recover – allowing reefs to bounce back.

In 2019, NOAA published a plan to help coral reefs in distress.

This was implemented during the 2023 heatwave in Florida, when coral nurseries were moved to deeper, cooler waters and sunshades were erected to protect corals from the sun.

Jennifer Koss, director of NOAA’s Coral Reef Conservation Program, said: ‘Climate model predictions for coral reefs have been suggesting, for years, that bleaching impacts would increase in frequency and magnitude as the oceans warm.

If the stress driving the bleaching diminishes, corals can recover – allowing reefs to bounce back. Pictured: Coral bleaching on the Great Barrier Reef

Figures suggest that since the 1950s, more than 50 per cent of the world’s coral reefs have died, with predictions that up to 90 per cent may die within the next century. Pictured: Coral bleaching in American Samoa

‘We are on the frontlines of coral reef research management and restoration, and are actively and aggressively implementing the recommendations of the 2019 Interventions Report.’

Figures suggest that since the 1950s, more than 50 per cent of the world’s coral reefs have died, with predictions that up to 90 per cent may die within the next century.

Thousands of marine animals including turtles, crabs and starfish depend on coral reefs for survival as they provide shelter, spawning grounds and protection from predators.

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