NOAA and partners race to rescue remaining Florida corals from historic ocean heat wave – NOAA Climate.gov

Animated satellite-based map showing the build-up of ocean heat stress in the waters around Florida between June 25 and July 23, 2023. Coral reefs in the southern portion of the Florida Keys have been experiencing extreme heat stress for weeks. In areas where the Degree Heating Week (DHW), which is directly related to the timing and intensity of coral bleaching, reached 4 °C-weeks, significant coral bleaching is expected; in areas where the DHW reached 8 °C-weeks, severe coral bleaching and significant mortality are expected (courtesy of NOAA Climate.gov, based on NOAA Coral Reef Watch data, Public Domain).

In mid-July 2023, heat-stressed corals in the southern Florida Keys began bleaching—expelling their food-producing algal partners—amid the hottest water temperatures ever documented in the region during the satellite record (dating back to 1985). As weeks of heat stress have continued to accumulate, bleaching and death have become more widespread, raising fears of a mass mortality event on the region’s already fragile reefs…