44% of Reef-Building Corals Face Elevated Risk

A reassessment of 774 reef-building coral species found that 340, or 44%, have an elevated relative risk of extinction, according to Nature Portfolio. The assessment classifies 33 species as critically endangered, 251 as endangered and 56 as vulnerable. ^[1]

Projected heat stress over the coming 30 years was identified as the leading threat for 93% of the species at elevated risk. The analysis used coral-cover trends aggregated across species and projections of severe bleaching under a middle-of-the-road climate scenario. ^[1]

The findings describe relative extinction risk, not whether or when a species will go extinct. The researchers also caution that coral-cover data served as a proxy for population declines rather than direct observations, and say the assessment predates the three hottest years on record from 2023 to 2025. ^[1]