Spatial and temporal variability of Honduran benthic communities and reef functionality throughout the fourth global coral bleaching event

Mass coral bleaching events are intensifying under climate change, yet their ecological consequences remain highly context dependent. We quantified shifts in benthic community structure, coral diversity and reef functionality during the 2023–2025 Fourth Global Mass Coral Bleaching Event (GCBE) in Tela Bay and Roatán, Honduras, two traditionally high-cover reef systems within the Mesoamerican Reef (MAR). Following three years of elevated heat stress (maximum DHW of 18 °C-weeks and 12 °C-weeks) both locations exhibited marked declines up to 60% in live coral cover, accompanied by increases of up to 58% in fleshy macroalgae cover, indicating shifts toward more algal-dominated benthic states. These shifts were accompanied by declines in coral diversity and reef functional index (RFI), suggesting reduced contribution of structurally important coral assemblages to key ecological processes. However, benthic community responses to bleaching were not uniform across sites. Increased multivariate dispersion following the event revealed substantial site-level heterogeneity, particularly in Tela Bay, where some sites retained greater coral cover and higher post-disturbance diversity indices, suggesting localized differences in resistance or early recovery potential. Coral community shifts were also strongly associated with declines in historically abundant taxa such as Agaricia tenuifolia , indicating that prolonged thermal stress can reduce the functional contribution of common and previously persistent coral taxa, not only structurally complex reef-building species. Our results show that even reef locations with high coral cover remain vulnerable to bleaching-driven reorganization of benthic communities and associated functional declines. Nevertheless, strong spatial variability among sites suggests that local environmental conditions and early-bleaching assemblage structure may mediate severity and recovery potential. These findings highlight the need to prioritize site-specific monitoring and management strategies in the MAR that identify and protect reefs with greater persistence potential under accelerating climate stress.