School of Biological Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
School of Biological Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Sci Total Environ. 2024 Jan 10;907:168066. doi: 10.1016/j.scitotenv.2023.168066. Epub 2023 Oct 26.
Reef-building corals create one of the most biodiverse and economically important ecosystems on the planet. Unfortunately, global coral reef ecosystems experience threats from numerous natural stressors, which are amplified by human activities. One such threat is ultraviolet radiation (UVR) from the sun; a genotoxic stressor that is a double-edged sword for corals as they rely on sunlight for energy. More intense UVR has been shown to have greater direct impacts on animal physiology, and these may be exacerbated by co-occurring stressors. The aim of this systematic literature review was to examine if the same applies to corals; that is, if the co-exposure of a constant stressor (UVR) with other stressors has a greater impact on coral physiology than if these stressors occurred separately. We reviewed the biochemical and cellular processes impacted by UVR and the defenses corals have against UVR. The main stressors investigated with UVR were temperature, nitrate, nutrient, oil, water motion, and photosynthetically active radiation (PAR). UVR generally worsened the physiological impacts of other stressors (e.g., by decreasing zooxanthellae and chlorophyll densities). There were species-specific differences in their tolerance to UVR (differences in zooxanthellae populations, sunscreen production and depth) and environmental stress (e.g., resilience to some oils), and that ambient levels of UVR were often beneficial (i.e., nullifying impacts of nitrates). We highlight areas of future investigation including examining and assessing other interacting stressors and their impacts (e.g., ocean acidification, ocean deoxygenation, toxins and pollutants), investigating impacts of multiple stressors with UVR on the coral microbiome, and elucidating the effects of multi-stressors with UVR across early-life history stages (especially larvae). UVR is a pervasive stressor to corals and can interact with other environmental conditions to compromise the resilience of corals. This environmental driver needs to be more comprehensively examined alongside climate change stressors (e.g., temperature increases, ocean acidification and hypoxia) to better understand future climate scenarios on reefs.
造礁珊瑚形成了地球上生物多样性最丰富和经济最重要的生态系统之一。不幸的是，全球珊瑚礁生态系统受到许多自然胁迫的威胁，这些胁迫因人类活动而加剧。其中一个威胁是来自太阳的紫外线辐射（UVR）；对于珊瑚来说，紫外线辐射是一种双重作用的遗传毒性胁迫源，因为它们依赖阳光获取能量。已经表明，更强烈的 UVR 对动物生理有更大的直接影响，并且这些影响可能会因同时存在的胁迫源而加剧。本系统文献综述的目的是检验这是否适用于珊瑚；也就是说，如果将恒定胁迫源（UVR）与其他胁迫源同时暴露，是否会对珊瑚生理产生比这些胁迫源单独作用更大的影响。我们审查了 UVR 影响的生化和细胞过程以及珊瑚抵御 UVR 的防御机制。与 UVR 一起研究的主要胁迫源是温度、硝酸盐、营养物、石油、水动力和光合有效辐射（PAR）。一般来说，UVR 会使其他胁迫源的生理影响恶化（例如，通过降低共生藻和叶绿素密度）。它们对 UVR 的耐受性存在种间差异（共生藻种群、防晒剂产生和深度的差异）和环境胁迫（例如，对某些石油的抵抗力），并且环境水平的 UVR 通常是有益的（即，抵消硝酸盐的影响）。我们强调了未来调查的领域，包括检查和评估其他相互作用的胁迫源及其影响（例如，海洋酸化、海洋缺氧、毒素和污染物），研究 UVR 与其他胁迫源对珊瑚微生物组的影响，以及阐明 UVR 与多胁迫源对早期生命史阶段（尤其是幼虫）的影响。UVR 是珊瑚的普遍胁迫源，它可以与其他环境条件相互作用，损害珊瑚的恢复力。这种环境驱动因素需要与气候变化胁迫源（例如，温度升高、海洋酸化和缺氧）一起更全面地研究，以更好地了解珊瑚礁的未来气候情景。
