Coral Bleaching
The phenomenon in which corals expel their symbiotic zooxanthellae due to stressors such as rising seawater temperatures, losing pigmentation and exposing their white skeletons. If high temperatures persist, it can lead to coral death.
Timeline (last 90 days)
Coral bleaching stems from the loss of symbiotic algae (zooxanthellae), and if it persists for several weeks the coral often dies.
Bleached coral does not die immediately; if the water temperature drops back in time, the zooxanthellae can recolonize, but if the high temperature persists, the coral will die on a large scale from starvation and disease.
Over the past forty years, three large-scale coral bleaching events have occurred globally, one of which, from 2014 to 2017, affected about 75% of the world's coral reefs.
When seawater temperature remains more than 1°C above the local maximum monthly mean temperature for the summer for more than 4 consecutive weeks, coral bleaching is triggered.
The 2023–2024 coral bleaching event has been confirmed as the fourth global bleaching event on record, affecting at least 62 countries and territories.
All Facts (5)
Coral bleaching stems from the loss of symbiotic algae (zooxanthellae), and if it persists for several weeks the coral often dies.
50%UnverifiedBleached coral does not die immediately; if the water temperature drops back in time, the zooxanthellae can recolonize, but if the high temperature persists, the coral will die on a large scale from starvation and disease.
50%UnverifiedOver the past forty years, three large-scale coral bleaching events have occurred globally, one of which, from 2014 to 2017, affected about 75% of the world's coral reefs.
50%UnverifiedWhen seawater temperature remains more than 1°C above the local maximum monthly mean temperature for the summer for more than 4 consecutive weeks, coral bleaching is triggered.
50%UnverifiedThe 2023–2024 coral bleaching event has been confirmed as the fourth global bleaching event on record, affecting at least 62 countries and territories.
50%