International Journal of Molecular Ecology and Conservation, 2025, Vol.15, No.6, 260-266 http://ecoevopublisher.com/index.php/ijmec 260 Research Insight Open Access Thermal Stress and Coral Resilience: Mechanisms of Bleaching and Adaptation Wenzhong Huang Biomass Research Center, Hainan Institute of Tropical Agricultural Resouces, Sanya, 572025, Hainan, China Corresponding email: wenzhong.huang@@hitar.org International Journal of Molecular Ecology and Conservation, 2025, Vol.15, No.5 doi: 10.5376/ijmec.2025.15.0026 Received: 09 Sep., 2025 Accepted: 21 Oct., 2025 Published: 07 Nov., 2025 Copyright © 2025 Huang, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Huang W.Z., 2025, Thermal stress and coral resilience: mechanisms of bleaching and adaptation, International Journal of Molecular Ecology and Conservation, 15(6): 260-266 (doi: 10.5376/ijmec.2025.15.0026) Abstract This study reviews the mechanism by which heat stress affects corals and explores how reactive oxygen species (ROS) generation, symbiotic rupture, and metabolic imbalance cause physiological damage and bleaching. Meanwhile, different albinism patterns and the regulation of their degrees by environmental and interspecific factors were analyzed. Then, focus on the mechanisms of coral resilience: including physiological recovery (such as heat shock proteins, metabolic regulation), ecological recovery (such as recolonization, community renewal), and the potential mechanisms of recovery failure. The evolutionary and ecological mechanisms of coral adaptation to heat stress were further discussed, including the screening of symbiotic algae, host genetic responses and ecological strategies. This study also combines the background of global change and proposes intervention strategies based on ecological engineering and management policies to enhance the recovery and resilience of coral systems. Studies have shown that the responses of corals to bleaching and heat stress are the result of the coordinated effects of multiple levels and mechanisms. Future conservation strategies should take into account both natural recovery potential and human intervention, and utilize molecular and ecological tools to monitor and guide the adaptation process. This research not only helps to deepen the understanding of the vulnerability of the coral-symbiotic algal system, but also provides an important theoretical basis for understanding the dynamic mechanism of coral recovery and adaptation under heat stress conditions. Keywords Coral; Heat stress; Albinism; Resilience; Symbiotic algae 1 Introduction Coral reef ecosystems are among the most productive and diverse ecosystems in the ocean, providing habitats for approximately a quarter of Marine species and supporting ecological services such as fisheries, tourism, and coastal protection through their complex structures and functions (Hoegh-Guldberg et al., 2017; Keshavmurthy et al., 2019). However, corals are particularly sensitive to environmental stress, especially the rise in sea water temperature. They are highly sensitive to both local (such as pollution, overfishing, and habitat destruction) and global (such as climate change and ocean acidification) stress factors. Their structural stability and biodiversity can be easily damaged by heat stress. It led to a rapid decline in coral coverage and ecosystem health (Putnam et al., 2017). In recent years, the frequency, intensity and duration of Marine heatwaves have all increased significantly, which is closely related to global warming. Abnormal sea surface temperatures caused by heat waves are an important trigger for coral bleaching. Coral bleaching refers to the breakdown of the relationship between corals and their symbiotic algae (such as Symbiodiniaceae), resulting in the expulsion of symbiotic algae or a decrease in their density, thereby losing pigment and basic metabolic support (Eakin et al., 2019). Frequent and extreme thermal events have made coral bleaching no longer an occasional event but a common phenomenon, posing a significant ecological threat to global coral reefs. Resilience refers to the ability of corals to restore their healthy state, species composition and functional structure after heat stress. Understanding the mechanism of coral resilience is crucial for ecological conservation (Mcleod et al., 2020; Bang et al., 2021; Shaver et al., 2022). On the one hand, it helps identify coral populations with high survival potential under future environmental pressures; On the other hand, it provides the basis for restoration and intervention for scientists and managers, such as strategies like ecological restoration, symbiotic algae intervention, and anthropogenic selection (Mcleod et al., 2019).
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