Reporting 2014-17 Coral Bleaching Observations to NOAA Coral Reef Watch

NOAA Coral Reef Watch (CRW) is undertaking an effort to determine the severity and distribution of recent coral bleaching and mortality, and compare these with satellite measurements of bleaching heat stress.

Mass coral bleaching events (some on the global scale) have been occurring more and more frequently in the last 30 years. A large number of coral reef areas in the United States and worldwide have experienced severe bleaching, sometimes in back-to-back events. For instance, elevated ocean temperatures in 2010 resulted in a major coral bleaching event in many parts of the world; this became known as the second global bleaching event on record. In 2014, record heat stress and bleaching were observed in the Commonwealth of the Northern Mariana Islands (for the second year in a row), the Northwestern Hawaiian Islands, the Main Hawaiian Islands, and the Marshall Islands, among other regions. We now know this was the beginning of the third documented global coral bleaching event, which persists today. As of April 2017, the ongoing global bleaching event continues to be the longest, most widespread, and most damaging on record. It has affected more reefs than any previous global bleaching event and has been worse in some locales (e.g., Great Barrier Reef, Kiribati, Jarvis Island). Heat stress during this event also has caused mass bleaching in several reefs that never bleached before (e.g., northernmost Great Barrier Reef).

This bleaching event provides an opportunity for comparison of bleaching observations from the field with the new CRW 5 km satellite coral bleaching heat stress product suite, released in May 2014. The new satellite products offer higher spatial (5 km) and temporal (daily) resolutions. They presently include sea surface temperature (SST), SST Anomaly, Coral Bleaching HotSpot, Degree Heating Week, a 7-Day Maximum Bleaching Alert Area, and a 7-Day SST Trend, as well as a set of 212 Regional Virtual Stations, associated Bleaching Heat Stress Gauges, and a free, automated Satellite Bleaching Alert Email System.

At this time, we are collecting information on coral bleaching from 2014 onwards for comparison with satellite data. (Click here for a copy of the email CRW sent to field partners around the world requesting their recent bleaching data.) If you wish to contribute bleaching observation data (including reports of 'no bleaching') to our effort, please complete BOTH the qualitative and quantitative bleaching report forms below, and email them to coralreefwatch@noaa.gov. Observations of both bleaching and no bleaching on your coral reefs are very important for the calibration/validation of CRW's satellite products.


NOAA Coral Reef Watch Bleaching Observation Forms:

Quantitative Questionnaire (Excel spreadsheet, 223kb, Revised Sep 14, 2015)

Qualitative Questionnaire (Microsoft Word document, 435kb, Revised Jul 30, 2015)



To learn more about the status of the ongoing global coral bleaching event, click here.


NOAA Coral Reef Watch has co-authored a new high-resolution global mass coral bleaching database, published in PLoS ONE on April 26, 2017. Databases described in the paper can be accessed here.

For additional information about the Top 10 Things Resource Managers and Other Coral Reef Stakeholders Can Do Before, During, and After a Bleaching Event, please visit: http://www.coris.noaa.gov/activities/projects/bleach_events/.