Coral reef bleaching has become a global crisis, with at least 53 countries, territories, or local economies affected since February 2023. Scientists from the National Oceanic and Atmospheric Administration and International Coral Reef Initiative have confirmed the widespread bleaching, which occurs when stressed coral expel the algae that provide them with food and color. If the bleaching is severe and prolonged, the coral can die.
Coral reefs are crucial ecosystems that support underwater life, protect biodiversity, and help prevent erosion. They also play a significant role in supporting local economies through tourism. Bleaching has been observed in various regions for some time, including the Great Barrier Reef in Australia, where 90% of the coral was affected in 2022, and the Florida Coral Reef, which experienced significant bleaching last year.
In order for bleaching to be declared on a global scale, significant bleaching had to be documented in each of the major ocean basins, including the Atlantic, Pacific, and Indian oceans, in both the Northern and Southern Hemispheres. As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe, according to Derek Manzello, NOAA Coral Reef Watch coordinator.
Climate change is identified as the biggest threat to coral reefs worldwide by marine biologist Selina Stead. Scientists are working to understand how coral responds to heat and identify heat-tolerant corals, but reducing carbon emissions is critical. Despite the widespread bleaching, there are some success stories, such as the Flower Garden Banks National Marine Sanctuary in the Gulf of Mexico, which was protected by its location in deeper water.