Reporting Coral Bleaching Data and Observations to NOAA Coral Reef Watch

NOAA Coral Reef Watch is continuing its work 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 in international locations 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 mid-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 persisted for three years. As of the end of May 2017, the third global coral bleaching event ended (National Oceanic and Atmospheric Administration (NOAA) 2017) but remains the longest, most widespread, and probably the most damaging coral bleaching event on record. It affected more reefs than any previous, documented global bleaching event and was worse in some locales (e.g., Great Barrier Reef, Kiribati, Jarvis Island). Heat stress during this event also caused mass bleaching in several reefs that never bleached before (e.g., northernmost Great Barrier Reef).

The 2014-17 global coral bleaching event, and subsequent mass bleaching of reefs around the globe (such as the widespread, severe heat stress and mass bleaching events on the Great Barrier Reef, Australia in early 2020 and early 2022), provide an opportunity for comparison of coral bleaching and mortality data and observations from the field with NOAA satellite data and Coral Reef Watch's current, operational daily global 5km-resolution satellite coral bleaching heat stress products.

**To contribute coral bleaching data and observations (including reports of NO bleaching) to our ongoing effort, please do the following:**

1. E-mail your data files (in Excel, Word, etc.) directly to, OR

2. Enter your data into Coral Reef Watch's Google Form, OR

3. Download Coral Reef Watch's quantitative observations questionnaire (below), enter your data, and e-mail the completed questionnaire to

NOAA Coral Reef Watch Quantitative Observations Questionnaire
(Excel spreadsheet, 13kb, Revised Sep 05, 2023)

What Can We Do?

Predictions pose a daunting future, where even the most conservative estimates suggest mass coral bleaching could occur annually on the majority of coral reefs worldwide by 2050. Increased collaboration among coral reef stakeholders is vital given the critical state of reefs all over the world, and their ecological, economic and societal benefits. In addition to reducing local threats to coral reefs, galvanizing global urgency and action to reduce atmospheric carbon dioxide (i.e., the root cause of rapid anthropogenic climate change) is critical to strengthen conservation and restoration efforts.

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