May 2, 2024

Coral Crisis: Massive Accumulation of Heat Stress in Summer 2023

This animation shows the development of built up heat stress from July through September 2023.
Utilizing Satellite Data to Monitor Corals
Satellite information offers insights into the stress levels of corals. Information for the item are put together by NOAAs Coral Reef Watch, which blends observations from polar orbiting satellites such as the NASA-NOAA Suomi NPP, and from geostationary satellites such as GOES, with computer system designs.
Observations have shown that when the built up heat stress reaches a worth of 4, considerable coral bleaching can result. At worths of 8, coral bleaching and prevalent death are most likely. By midway through this animation, in August, heat stress throughout much of the area currently skyrocketed well above both of those thresholds. According to NOAA, cumulative heat tension by late September 2023 hit 22 ° C-weeks( 40 ° F-weeks), almost triple the previous record for the area.
Early Signs and Effects of Bleaching
Bleaching was already observed in some areas as early as July. Notice that locations of reef (gray) near the Florida Keys, Cuba, and the Bahamas, are among the first locations to show high cumulative heat stress. Cyclone Idalia in late August helped cool surface waters rather, but only briefly.
Nearing mid-October, waters around the Florida Keys were under a lightening watch. Further south, waters around parts of Cuba and the Bahamas remained at lightening alert level 2, the highest level of the scale, signifying that extreme whitening and mortality are likely.
NASA Earth Observatory animation by Wanmei Liang, utilizing Daily 5km Degree Heating Weeks information from Coral Reef Watch. Coral reef data from UNEP-WCMC, WorldFish Centre, WRI, TNC.

Some locations– including the seas around Florida, Cuba, and the Bahamas– saw especially high temperatures, with ramifications for the health of coral reefs.
Lightening takes place when stressed out corals expel the algae that live inside them, removing corals of their color. Observations have actually shown that when the collected heat stress reaches a value of 4, considerable coral lightening can result. At values of 8, coral whitening and prevalent mortality are likely. Notification that areas of coral reef (gray) near the Florida Keys, Cuba, and the Bahamas, are among the first locations to show high cumulative heat tension.

In 2023, rising sea temperature levels, magnified by human activities and El Niño, threatened coral reefs, specifically around Florida, Cuba, and the Bahamas. Satellite data indicated high risks of coral whitening and mortality in these regions by mid-October.
The seas around Florida, Cuba, and the Bahamas saw big build-ups of heat tension start in summertime 2023, with ramifications for the health of coral reefs.
For several months in 2023, global sea surface temperatures reached record-high levels. This surge was sustained by years of human-caused climate warming and a current increase from the natural environment phenomenon El Niño. Some locations– including the seas around Florida, Cuba, and the Bahamas– saw particularly heats, with implications for the health of reef.
The Impact on Coral Reefs
Corals thrive within a small temperature range and become stressed when water is cold or too hot. Whitening takes place when stressed corals expel the algae that live inside them, removing corals of their color. Extreme lightening can leave a reef vulnerable to starvation, illness, and even death. Observations made by divers in the Florida Keys found that the marine heatwave in the summer of 2023 caused widespread bleaching.