![Image](/images/2024/07/20/sunx_malta_logo_border-white-png.png)
About
Climate Friendly Travel
Resources
Contact
Geoffrey Lipman, SUNx Co-founder info@thesunprogram.com
+32495250789
NOAA Declares a Global Coral Bleaching Event in 2023
Scientists warn that the die off hit previously unaffected areas and more resilient species. Reef declines are leaving coastal communities increasingly vulnerable to storm surges.By Bob BerwynFrom shallow-water reefs in the Red Sea to graceful gorgonian species in the Caribbean and the rugged branching corals that form the structure of the Great Barrier Reef, the past year brought bleaching, decline and death to coral reefs around the world.
The National Oceanic and Atmospheric Administration and the International Coral Reef Initiative today confirmed the scope of recent reef damage, announcing that prolonged ocean heatwaves caused the fourth global bleaching episode, following similar events in 1998, 2010 and 2014-2017.In the past 12 months, bleaching has been documented in both the Northern and Southern Hemisphere, and persists across the Atlantic, Pacific and Indian oceans, said Derek Manzello, coordinator of NOAA’s Coral Reef Watch.Overheated oceans disrupt the symbiosis of corals and algae, which turns 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.“People generally don’t know that bleaching is only one very obvious manifestation of heat stress,” said Terry Hughes, a preeminent Australian coral researcher who has recently assumed a public watchdog role of his government’s efforts to downplay the impacts of Australia’s continued fossil fuel production, and to greenwash the damage warming is doing to the Great Barrier Reef.“In both Florida last summer, and on the Great Barrier Reef during severe heat events, the corals don’t have time to bleach,” he said. “They just melt. One day they’re colorful and healthy and the next week they’re dead.”More and more frequently, he said, water temperatures are rising more than 3 degrees Celsius above the normal summer maximums, causing acute heat stress that kills corals outright. Corals can also fluoresce, turning very colorful, often in shades of purple or pink, which is an “emergency response” in which they produce a protein with sunscreening properties.“They’re basically saying, ‘I’m dying here, so I’m going to produce this protein, see if it helps me,’” he said. “But in our experience, if they get to a fluorescent stage, the temperatures are so high that most of them will die.”Manzello said the current coral bleaching has been extremely severe and widespread in the Atlantic Ocean, across the wider Caribbean and in Florida.“Brazil is going through it right now,” he said. “They’re experiencing record-setting heat stress that they’ve never had before.” Across the Atlantic, 98.5 percent of reef areas experienced bleaching-level heat stress in the last year, he added.“On a global scale, about 54 percent of reef areas have experienced bleaching level heat stress in the last year,” he said. Bleaching conditions are increasing by 1 percent each week, so the affected area will likely soon surpass the record of 56.1 percent set during the 2014-2017 global bleaching disaster. New types of corals are also being affected, as are new geographic areas.Along the Mesoamerican Reef, the second-largest barrier reef in the world, which extends down the eastern coasts of southern Mexico and Central America, soft gorgonian corals also bleached for the first time on record, according to Lorenzo Alvarez-Filip, a coral researcher with the Biodiversity and Reef Conservation Laboratory in Puerto Morelos, Mexico. The loss of reefs in 2023 is an ecological trauma that will leave lasting marks, he said.The 2023 bleaching was destructive along the Mesoamerican Reef because of the long-lasting ocean heat wave that began in May and persisted for months, peaking with water temperatures more than 3.5 degrees Celsius above average in August, he said. Previous ocean heatwaves in the Caribbean were short-lived, peaking in September and then waning as the waters cooled in the autumn.