Climate change-related disturbances in 2024 drive the largest known population of elkhorn coral (Acropora palmata) in Barbados to the brink of extirpation

Climate change is leading to global increases in frequency and severity of marine heatwaves, increasingly contributing to coral reef degradation. In 2024, Barbados was impacted by the passage of Hurricane Beryl and the most severe marine heatwave to date. Here, we report on the fate of the largest known population of the foundational Caribbean reef building coral, Acropora palmata , in Barbados in the face of such disturbances. Between June 2024 and March 2025, we tagged, measured and monitored (biweekly to monthly) the health status of 33–41 A. palmata colonies at Mullins Reef on Barbados’ west coast. On July 1, Hurricane Beryl passed south of Barbados, causing the loss of 36.4% of tagged colonies. On August 4 and September 2 2024, average daily cumulative heat stress reached four and eight Degree Heating Weeks (DHW), respectively, peaking on November 12 at an unprecedented 24.2 DHW. After Beryl, tagged colonies that were not destroyed remained healthy until September 16, when some started to show bleaching signs. By October 29, all colonies were fully bleached and by December 18 most colonies had died. By February 14 2025, only one colony remained alive; it had regained full coloration, but lost > 50% of its live tissue. The collapse of the most important A. palmata population on the west coast, coupled with the devastating impact of Hurricane Beryl on the south coast, provide a stark warning that A. palmata might have now reached functional extinction in Barbados, abruptly ending two decades of slow A. palmata recovery.