Global Coral Bleaching Event Declared by NOAA in 2023

Coral reefs around the world have experienced a devastating year, with bleaching, decline, and death affecting reefs in various oceans. The National Oceanic and Atmospheric Administration and the International Coral Reef Initiative have confirmed that prolonged ocean heatwaves have caused the fourth global bleaching episode, following similar events in previous years.

Derek Manzello, coordinator of NOAA’s Coral Reef Watch, stated that bleaching has been documented in both the Northern and Southern Hemisphere, persisting across the Atlantic, Pacific, and Indian oceans. The overheated oceans disrupt the symbiosis of corals and algae, turning reefs white. If the water cools relatively quickly, some corals can recover, but increasingly, ocean temperatures are soaring so high that it’s killing corals outright.

Terry Hughes, an Australian coral researcher, highlighted the severity of the bleaching, stating that corals are dying due to acute heat stress caused by rising water temperatures. The bleaching conditions are increasing rapidly, with 54 percent of reef areas experiencing bleaching-level heat stress in the last year.

New types of corals are also being affected, with soft gorgonian corals in the Mesoamerican Reef bleaching for the first time on record. The loss of reefs in 2023 is described as an ecological trauma that will leave lasting marks.

The Intergovernmental Panel on Climate Change warns that if global warming exceeds 1.5 degrees Celsius above pre-industrial levels, close to 80 percent of existing reefs will die or be severely diminished. The impact of coral reef destruction goes beyond ecological loss, affecting coastal fisheries and the protection of shorelines from tropical storms and hurricanes. The urgency to address climate change and protect coral reefs has never been more critical.