Indian Ocean Coral Bleaching

Indications are for a hot 2024 bleaching season in the Western Indian Ocean, with moderate to high bleaching expected

 2023 was reported as the hottest year ever, with every month since mid-year breaking prior records by a large margin (fig), and a high likelihood that global temperatures will exceed the critical boundary of 1.5°C at some point during 2024. At the start of the southern summer period, both Indian Ocean Dipole and ENSO index are strongly positive and in phase, repeating conditions in in 1997/98.  

Read more in the latest 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 2016-2023 click 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.