'Most intense' bleaching event ever: Global coral reefs under danger
A concerning update from global scientists and governmental bodies says 84 per cent of the world's coral reefs have experienced heat stress from the continuous, 'most intense' bleaching event
Most of the world's coral reefs are facing a crisis from an ongoing, massive bleaching event that began in 2024, according to an update published on Wednesday.
A year after the fourth worldwide coral bleaching event was declared by the International Coral Reef Initiative (ICRI), the "most intense" affair is still ongoing––with alerts continuing to be issued around the globe, the organization said.
SEE ALSO: Global coral bleaching event expands, now the largest on record
In an update released on Wednesday, ICRI said 84 per cent of the coral reefs on the planet have been affected by bleaching-level heat stress from Jan. 1, 2023 to March 30, 2025. The bleaching has caused damage in 82 countries, territories and economies.
The alarming briefing on the active bleaching event comes on the heels of last month being named the second-warmest March on record, globally, and Europe's hottest.
"The fact that this most recent, global-scale coral bleaching event is still ongoing takes the world’s reefs into unchartered waters. In the past, many coral reefs around the world were able to recover from severe events like bleaching or storms. We need to continue to observe and measure if and how reefs will recover and change, to help inform the combination of conservation measures most suited for a particular reef," said Britta Schaffelke, manager of international partnerships at the Australian Institute of Marine Science, in a news release.
Current bleaching event deemed 'unprecedented' in May 2024
In its update published on Wednesday, ICRI mentioned that scientists referred to the fourth global coral bleaching event as “unprecedented,” as early as May 2024. As well, because of the magnitude of the bleaching, a prediction system had to add three new levels (Levels 3-5) to its alert scale to pinpoint the elevated risk of mass coral mortality.
(Brett Monroe Garner/ Moment/ Getty Images)
Before the addition, the highest level (2) indicated the risk of mortality to heat-sensitive corals. Now, Level 5 outlines the threat of more than 80 per cent of all corals on a reef dying due to extended bleaching.
Environmental aggravators such as heat result in corals discharging their colourful, energy-producing algae that live inside them, leaving them white as they bleach, according to ICRI. However, if the conditions can return to normal in a timely manner, corals can retrieve their algae and usual health. But the corals can die if the water temperatures stay too warm for too long.
"The main cause of large-scale coral bleaching events is higher ocean temperatures. Last year was the hottest on record and the first to reach over 1.5°C warmer than pre-industrial times, due to human-induced climate change. This contributed to record-breaking ocean temperatures, and tripled the previous record number of marine heat waves around the world," said ICRI, in the news release.
According to Reuters, marine biologists warned early last year that the world's reefs were on the verge of a mass bleaching after months of record-breaking ocean heat, propelled by human-induced climate change and El Niño.
According to a 2015 study in Science Direct, about a third of all known marine life relies on reefs. Another study estimated that one billion people benefit from them, directly or indirectly.
WATCH: Heat stress leads to widespread coral bleaching in Great Barrier Reef
With files from Reuters.
Thumbnail courtesy of Getty Images/AndriiSlonchak/1905292613-170667a.
