Half of the planet’s coral reefs suffered major damage from a heatwave that occurred almost a decade ago, according to research released Tuesday, which warns that a similar and more severe phenomenon is unfolding now. Corals are invertebrate animals that build reefs, colorful, multi-shaped structures that serve as habitat for marine species.
Scientists have warned that rising ocean temperatures driven by human activity threaten to kill corals en masse through bleaching, a form of deterioration that causes corals to lose the algae living inside them, turning them transparent or white and making them more vulnerable.
A study by several organizations, including the Smithsonian Tropical Research Institute (STRI) based in Panama, warns that “half of the world’s coral reefs” experienced “significant bleaching” due to a heatwave recorded between 2014 and 2017. Experts estimate that “more than 50% of coral reefs worldwide suffered significant bleaching and 15% experienced significant mortality,” according to a Smithsonian statement.
The research warns that bleaching reduces growth, lowers reproduction, and can even kill reefs, which in turn affects tourism, fishing, food supplies, and coastal protection. “We’re seeing that reefs don’t have enough time to recover properly before the next bleaching event occurs,” said Scott Heron of Australia’s James Cook University, quoted in the report.
“Our results show that the third global bleaching event was by far the most severe and widespread on record,” said Sean Connolly, a Smithsonian scientist. However, reefs “are currently undergoing a fourth event that is even more severe, which began in early 2023,” Connolly warned.
The study is based on analysis of 15,000 reefs in 41 countries. Scientists combined satellite images of ocean water temperatures with reef observations gathered through underwater and aerial surveys. “This is the most geographically broad analysis of coral bleaching studies conducted to date,” Connolly noted.
Earth has lost 50% of its corals over the past 30 years, according to STRI.
