Thermal Stress, Microplastic Pollution, and Coral Reef Resilience: A ComparativeEnvironmental Analysis of the Great Barrier Reef and the Coral Triangle

Abstract

Coral reef ecosystems are increasingly exposed to interacting climate and pollution stressors that alter physiological tolerance, microbial stability, carbonate accretion, and long-term ecological resilience. This study examines how thermal stress and microplastic contamination influence coral reef vulnerability through a comparative environmental analysis of the Great Barrier Reef and the Coral Triangle. The article argues that reef degradation cannot be adequately explained by ocean warming alone because local pollution, hydrodynamic retention, reef governance, and biological community structure mediate the ecological consequences of marine heatwaves. Using interdisciplinary environmental analysis, satellite-derived thermal stress evidence, peer-reviewed ecological studies, coral bleaching records, microplastic pollution literature, and international scientific reports, the study compares two reef systems with high ecological significance but different oceanographic, institutional, and anthropogenic pressures. The findings indicate that thermal anomalies drive bleaching risk through disruption of coral–Symbiodiniaceae photosymbiosis, oxidative stress, and metabolic imbalance, whereas microplastics intensify ecological vulnerability by altering coral feeding, microbial assemblages, disease susceptibility, and contaminant exposure. The comparative evidence suggests that the Great Barrier Reef exhibits stronger monitoring and governance capacity but high recurrent thermal exposure, while the Coral Triangle exhibits exceptional biodiversity and adaptive potential but higher coastal pollution pressure and governance fragmentation. This article contributes to natural sciences scholarship by integrating climate physiology, pollution ecology, marine biogeochemistry, and reef resilience theory into a comparative framework for understanding coral ecosystem sustainability.