MARINE BIOLOGY AND MOLECULAR ECOLOGY: CORAL RESILIENCE TO CLIMATE CHANGE

Abstract

 Coral reefs are increasingly threatened by climate-induced stressors such as ocean warming and acidification, necessitating a deeper understanding of species-specific resilience mechanisms. This study investigates the physiological and molecular responses of three reef-building coral species—Acropora millepora, Pocillopora damicornis, and Porites lobata—under simulated climate stress conditions. A mixed-methods experimental framework was applied, combining field-based sampling, controlled thermal and pH stress assays, and high-throughput RNA sequencing to assess photochemical efficiency (Fv/Fm), symbiont density, chlorophyll a concentration, and transcriptional resilience indices (TRI). A total of 180 samples across nine treatment sets were analyzed. Results revealed that P. lobata demonstrated superior physiological stability and the lowest TRI values (<1.0), indicating strong transcriptional robustness under stress. In contrast, P. damicornis exhibited significant declines in Fv/Fm and symbiont density, coupled with high TRI values (>2.0), reflecting pronounced transcriptomic disruption. A. millepora presented moderate resilience, with variable outcomes across replicates. Functional enrichment of differentially expressed genes implicated oxidative stress response, apoptosis regulation, and symbiont-host communication as key processes underpinning resilience. Complex visualizations including hybrid box-strip plots and interaction heatmaps confirmed interspecies differences and validated TRI as a predictive metric. The findings were further reinforced by ecological expert feedback, which aligned with model predictions. Overall, this study identifies P. lobata as a climate-resilient coral species and presents a replicable framework for evaluating coral stress responses using integrative molecular and ecological metrics. The approach has broad implications for reef conservation, restoration planning, and adaptive management under ongoing climate change.