Nature study finds 340 of 774 assessed reef-building coral species are threatened

16 October 2026

A study published in Nature on 15 October 2026 reassessed the International Union for Conservation of Nature Red List status of 892 reef-building coral species that were first assessed in 2008. Of these, 774 species had enough data to be assessed, and 340 of them, or 44 per cent, were classified as threatened. The breakdown is 33 Critically Endangered, 251 Endangered and 56 Vulnerable. Most listings follow from projected thermal stress: because species-level population trends are rarely available, the authors inferred population reductions from global coral cover trends and projected annual severe bleaching under the SSP2-4.5 scenario over three decades, then adjusted the estimates with trait-based vulnerability scores. The authors note that the assessment predates the fourth global coral bleaching event of 2023 to 2025 and the first annual mean exceedance of 1.5 degrees Celsius of warming. The paper cautions that the Red List measures relative extinction risk and does not predict whether or when a species may go extinct.