Ten years of coral reef benthic changes in the Central Mexican Pacific

Over the past five decades, approximately one-third of the planet’s live coral cover has been lost, primarily as a consequence of environmental stressors driven by anthropogenic activities, the most severe being the alteration in the periodicity and intensity of El Niño Southern Oscillation (ENSO) events associated with climate change. During the 2023 El Niño event, the coral reef ecosystems in the Mexican Central Pacific experienced a 90% loss of coral cover; however some particular sites acted as refugees with minimal or no loss in the coralline area. Our study describes benthic variability patterns in three of the best-preserved coral reef ecosystems in the Central Mexican Pacific (CMP) region: Chamela Bay, Tenacatita–Barra de Navidad Bays, and Santiago–Manzanillo Bays, each with an average coral cover of ≥ 29%. We analyzed changes in the cover of major benthic groups (corals, algal turf, soft macroalgae, and encrusting calcareous algae) and their relationships with environmental drivers (sea surface temperature, local thermal anomalies, chlorophyll-a levels, and diffuse attenuation coefficient) over thirteen years. Using beta regression models, data were analyzed to determine the local response of each benthic group in response patterns to environmental variability. All three systems showed high resilience to environmental disturbances, with coral cover recovery of up to 74% and regulatory mechanisms that help control the algal blooms. Pronounced seasonal upwelling processes are key to regional environmental variability and may act as stress mitigators during positive ENSO phases. Similarly, the historical ecological processes experienced by each locality have driven the selection, acclimatization, and resilience strategies specific to each benthic community.