According to the U.S. National Oceanic and Atmospheric Administration (NOAA), nearly two-thirds of the world’s coral reefs have been subjected to heat stress bad enough to trigger bleaching over the past year.
Key points
- NOAA announced in April 2024 that the world’s coral reefs were in the throes of a fourth mass bleaching event, as climate change combined with an El Nino climate pattern has pushed ocean temperatures to record highs.
- Now (May 24), the agency reports some 60.5% of the world’s reef area has been affected and that number is still rising.
- Triggered by heat stress, coral bleaching occurs when corals expel the colourful algae living in their tissues. Without these helpful algae, the corals become pale and are vulnerable to starvation and disease.
- Scientists have documented mass bleaching in at least 62 countries and territories, with India and Sri Lanka recently reporting impacts.
- Corals in the Atlantic Ocean have been hit hardest by soaring ocean temperatures, with 99.7% of the basin’s reefs subjected to bleaching-level heat stress in the past year.
