After a year of ocean heat waves and unprecedented temperatures off the coast of Florida that alarmed conservationists last summer, the world is currently experiencing a “global coral reef bleaching event,” the fourth ever recorded and the second in the past decade, according to climate scientists at the National Oceanic and Atmospheric Administration (NOAA).

Coral reef bleaching occurs as warming temperatures stress the tiny organisms that form the foundation of complex reef ecosystems, and without relief from cooler waters, bright and colorful reefs turn a ghostly white. Bleaching increases the risk that reefs suffer disease, starvation and death.

If current trends continue, the world will soon witness the most severe global bleaching event ever recorded, according to Derek Manzello, an ecologist and coordinator of NOAA’s Coral Reef Watch program.

Bleaching occurs when stress from heat breaks down the symbiotic relationship that transfers nutrients from algae to coral. Over the past year, about 54 percent of the global ocean area that is home to coral reefs experienced heat stress at levels that cause bleaching, according to NOAA’s Global Bleaching Event Index. The index peaked at 56 percent between 2014 and 2017.

“That 54 percent number has been going up by about 1 percent per week now for a few months, so it’s likely that the record will be broken here in a few weeks,” Manzello said in an interview. “The forecast is that El Niño is coming to an end and will switch to La Niña, and once that happens, that number will start coming down.”

Global ocean warming has increased steadily since the 1970s. Since early 2023, scientists have confirmed the mass bleaching of coral reefs throughout the tropics, including coastal areas of Florida and Brazil; the eastern Tropical Pacific stretching from Mexico down to........

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