Rapid Fire
Fourth Global Mass Coral Bleaching Event
- 20 Apr 2024
- 2 min read
Coral Reef Watch (CRW) of the United States and the International Coral Reef Initiative (ICRI) have confirmed the fourth global mass coral bleaching event in 2023-2024.
- This is the second such event in the last 10 years and comes at a time when global oceans have also recorded unprecedented heat in 2023 and 2024.
- The El Nino conditions in the equatorial Pacific Ocean added onto the general trend of warming over land and oceans.
- During El Niño events, warm ocean currents from the central and eastern Pacific Ocean move towards the western Pacific, causing sea surface temperatures to rise in many regions.
- Among long-term patterns, ocean heating and mass coral bleaching are closely tied to the occurrence of El Nino events.
- This warming effect of El Niño contributes to ocean heating, which stresses coral reefs.
- The various factors responsible for coral bleaching are increasing sea surface temperatures, extensive marine heatwaves, ocean acidification and pollution.
- When sea surface temperatures and ocean heat in general rise, the algae on the hard corals die off. This makes the corals white.
- This process is known as ‘coral bleaching’. Once bleached, the corals can become vulnerable to diseases and eventually die.
Read more: Coral Bleaching in Great Barrier Reef
