Indian Ocean Coral Bleaching

The long protracted La Niña event that began in 2020 is gradually ending. Decadal prediction anticipates 2023 to be hotter than 2022 (UK Met office).

Globally, 2022 was relatively cool (though slightly warmer than 2021) which is consistent with a La Niña state that began in September 2020 and persisted throughout 2022. The cooler conditions provided a haven for WIO reefs, and no significant bleaching was reported in the region in 2022. Read more in the alert on the right.


For materials and guidance on responding to coral bleaching and mortality, visit this page. Bleaching alerts from 2009 to date are available further down the page, and more information is available at these links – background, and methods.

Indian Ocean Bleaching observations Dashboard 2016-2021click to open the dashboard

Report Coral Bleaching

Submit basic observations on coral bleaching through this embedded window, or go to the google-form at this link. All data will be submitted to the global bleaching form supported by the NOAA Coral Reef Watch programme, and made accessible on a WIO regional database under development.


All past bleaching alerts, from 2009 to the current year, are in the window below. Click on the relevant year, or scroll left/right within each year for additional alerts. Alerts are published between January and May each year, with fewer alerts when bleaching risk is low.