Thermal extremes and multi-stressor environmental variability across the Belize Barrier Reef System

A marked intensification of thermal stress, including more frequent and severe marine heatwaves (MHWs) and elevated Degree Heating Weeks (DHW), has been observed across the Belize Barrier Reef System (BBRS) from 1985 to 2025. The study, integrating multi-stressor environmental data such as sea surface temperature, ocean color, currents, wind, climate indices, and carbonate-system proxies, reveals spatially heterogeneous reef exposure. While all site clusters experienced bleaching-level DHW in 1998, the highest thermal stress occurred in 2023–2024, with some sites exceeding critical thresholds. Distinct environmental regimes were identified, with Site A facing acute multi-stressor conditions and Site I experiencing chronic stress. Carbonate-system proxies indicate increasing ocean acidification, though variability exists among sites. This integrated framework underscores the complex interplay of thermal stress, water quality, hydrodynamics, and climate change on reef resilience.

Smith, N. T., & Hsu, P.-C. (2026). Thermal extremes and multi-stressor environmental variability across the Belize Barrier Reef System. Journal of Sea Research, 213, 102729. https://doi.org/10.1016/j.seares.2026.102729