44% of assessed coral species with sufficient data face extinction risk
A new global assessment classifies 340 of 774 reef-building coral species with sufficient data as threatened; the result measures species risk, not the share of reefs already lost.
A global reassessment published October 15 places 340 reef-building coral species in threatened categories.
The widely reported 44% uses the 774 species with enough evidence for classification; another 118 of the 892 examined were data deficient. Threatened includes vulnerable, endangered and critically endangered—not extinct. [1][2]
Because population trends are unavailable for most species, the researchers used coral-cover change, projected severe bleaching and species traits to estimate relative risk. The assessment’s historical data end in 2020. NOAA has since documented a global bleaching event spanning 2023–2025, a separate observation that underscores the assessment’s time lag. [1][2][3]
The result helps identify conservation priorities; it cannot tell us when a particular species will disappear. Protecting surviving reefs still matters, alongside reducing the warming that drives repeated heat stress. [1][2]
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- IUCN · October 15 reassessment
Original release gives 892 examined, 118 data deficient, 774 with sufficient data and 340 threatened. Historical assessment data end in 2020.
- Nature · Original research abstract
Publisher abstract retrieved through web search after collection; direct full-page access failed. The abstract describes proxy population trends and bleaching projections, and warns that Red List risk does not predict whether or when extinction occurs. Full methods were not independently reanalysed.
- NOAA Coral Reef Watch · Bleaching record
Original monitoring account, updated June 2, 2026, documents the 2023–2025 global bleaching event. Independent observational context, not replication of the species-risk assessment and not the same denominator.
Images & figures
AI-generated editorial illustration of a coral colony; not an identified species, specimen, bleaching photograph or quantitative representation.
Euangelion · AI-generated editorial illustration · Source · Usage terms
The additional 118 data-deficient species sit outside the 774-species denominator.
Euangelion · Source · Usage terms · Download figure