The world is currently experiencing the most extensive coral bleaching event ever recorded, with over 84% of coral reefs across at least 83 countries and territories affected since January 2023. This marks the fourth global bleaching event documented by the National Oceanic and Atmospheric Administration (NOAA) and the International Coral Reef Initiative (ICRI), surpassing previous events in both scale and severity.
Coral bleaching occurs when elevated sea temperatures, often driven by climate change and phenomena like El Niño, cause corals to expel the symbiotic algae (zooxanthellae) that provide them with nutrients and their vibrant colors. Without these algae, corals turn white and become more susceptible to disease and death.
The ongoing bleaching event has impacted reefs in the Atlantic, Pacific, and Indian Oceans, including areas previously considered resilient, such as the Gulf of Aqaba and Raja Ampat. Notably, the Great Barrier Reef has experienced its fifth mass bleaching event since 2016.
In response to the unprecedented severity, NOAA has expanded its bleaching alert scale to include a fifth level, indicating near-total coral mortality.
The ecological ramifications are profound. Coral reefs support approximately 25% of marine species, provide coastal protection, and are vital to the livelihoods of millions of people worldwide. The degradation of these ecosystems threatens biodiversity, food security, and economic stability in many regions.
Scientists warn that without significant reductions in greenhouse gas emissions, coral reefs could largely disappear by the end of the century. Efforts to mitigate the damage include coral restoration projects and international funding initiatives, but experts emphasize that addressing the root causes of climate change is essential for the long-term survival of coral ecosystems.
