Environment Laboratories, International Atomic Energy Agency, 4a, Quai Antoine Ier, 98000, Monaco; Australian Rivers Institute, Griffith University, Southport, QLD, 4215, Australia.
CSM - Centre Scientifique de Monaco, Equipe Ecophysiologie corallienne, 8 Quai Antoine 1er, 98000, Monaco.
Environ Pollut. 2020 Aug;263(Pt A):114559. doi: 10.1016/j.envpol.2020.114559. Epub 2020 Apr 12.
We investigated physiological responses including calcification, photosynthesis and alterations to polar metabolites, in the scleractinian coral Stylophora pistillata exposed to different concentrations of polyethylene microplastics. Results showed that at high plastic concentrations (50 particles/mL nominal concentration) the photosynthetic efficiency of photosystem II in the coral symbiont was affected after 4 weeks of exposure. Both moderate and high (5 and 50 particles/mL nominal) concentrations of microplastics caused subtle but significant alterations to metabolite profiles of coral, as determined by Nuclear Magnetic Resonance (NMR) spectroscopy. Specifically, exposed corals were found to have increased levels of phosphorylated sugars and pyrimidine nucleobases that make up nucleotides, scyllo-inositol and a region containing overlapping proline and glutamate signals, compared to control animals. Together with the photo-physiological stress response observed and previously published literature, these findings support the hypothesis that microplastics disrupt host-symbiont signaling and that corals respond to this interference by increasing signaling and chemical support to the symbiotic zooxanthellae algae. These findings are also consistent with increased mucus production in corals exposed to microplastics described in previous studies. Considering the importance of coral reefs to marine ecosystems and their sensitivity to anthropogenic stressors, more research is needed to elucidate coral response mechanisms to microplastics under realistic exposure conditions.
我们研究了生理反应，包括钙化、光合作用和极地代谢物的变化，在暴露于不同浓度聚乙烯微塑料的石珊瑚 Stylophora pistillata 中。结果表明，在高浓度塑料（50 个颗粒/毫升名义浓度）下，珊瑚共生藻的光系统 II 光合作用效率在暴露 4 周后受到影响。中等和高浓度（5 和 50 个颗粒/毫升名义浓度）的微塑料都会对珊瑚的代谢物图谱产生微妙但显著的影响，这是通过核磁共振（NMR）光谱法确定的。具体而言，与对照动物相比，暴露的珊瑚中发现磷酸化糖和构成核苷酸的嘧啶核苷碱基、肌醇和包含重叠脯氨酸和谷氨酸信号的区域的水平升高。与观察到的光生理应激反应和以前发表的文献一起，这些发现支持了这样一种假设，即微塑料会破坏宿主-共生体信号，而珊瑚通过增加信号和对共生的虫黄藻的化学支持来对这种干扰做出反应。这些发现也与以前的研究中描述的暴露于微塑料的珊瑚中粘液产生增加的情况一致。考虑到珊瑚礁对海洋生态系统的重要性及其对人为胁迫的敏感性，需要进行更多的研究来阐明珊瑚对微塑料在现实暴露条件下的反应机制。
