Yazhou Bay Innovation Institute/Key Laboratory for Coastal Marine Eco-environment process and Carbon Sink of Hainan Province/Modern Marine Ranching Engineering Research Center of Hainan/College of Ecology and Environment, Hainan Tropical Ocean University, Sanya 572022, China.
Hainan Academy of Environmental Science, Haikou 571126, China.
J Hazard Mater. 2024 Dec 5;480:135898. doi: 10.1016/j.jhazmat.2024.135898. Epub 2024 Sep 18.
Coral reefs possess extremely high ecological value in tropical and subtropical waters worldwide. Microplastics as emerging and pervasive pollutants pose a great threat to the health of coral ecosystems. However, in situ studies on microplastics pollution and its impacts in coral ecosystems globally are limited. The occurrence characteristics of microplastics in the environment mediums and reef-dwelling organisms were investigated in coral reef areas from the southern Hainan Island, and the impacts of microplastics on corals in situ were evaluated in this study. Average microplastics abundance was 9.48 items L in seawater, 190.00 items kg in sediment, 0.36 items g in coral, 1.50 items g in shellfish, 0.48 items g in fish gill, and 1.71 items g in fish gastrointestinal tract. The prevalent microplastics in the above samples were characterized as being less than 1000 µm in size, fibrous, and transparent, with predominant polymer types as polyethylene terephthalate, polypropylene, polyethylene, and rayon. The microplastic enrichment capacity of different corals varied (Pocillopora > Acropora > Sinularia). Notably, microplastics were more abundant on the surface of corals compared to their interiors, with distinct characteristics observed, including larger-sized (>500 µm) and fiber-shaped polyethylene terephthalate microplastics on the surface and smaller-sized (20-200 µm) fragmented polyethylene microplastics within coral interiors. Furthermore, the investigation showed species-specific impacts of microplastics on corals in situ, including photosynthetic activity of photosymbionts and antioxidant and immune activities of corals. Furthermore, the ecological risks of microplastics were minor across most environmental media in the studied areas, with exceptions in the bottom seawater and surface sediment of YLW, which exhibited extreme and medium risk levels, respectively. Coral risk levels were generally medium, except for dangerous levels in DDH and high levels in LHT. The potential sources of microplastics in the marginal reefs of southern Hainan Island were primarily tourism, residential, and fishing activities.
在全球热带和亚热带水域，珊瑚礁具有极高的生态价值。微塑料作为新兴的、普遍存在的污染物，对珊瑚生态系统的健康构成了巨大威胁。然而，目前全球范围内对珊瑚生态系统中微塑料污染及其影响的实地研究还很有限。本研究调查了海南岛南部珊瑚礁区环境介质和礁栖生物中微塑料的分布特征，并评估了微塑料对珊瑚的原位影响。结果表明，海水中微塑料的平均丰度为 9.48 个/L，沉积物中为 190.00 个/kg，珊瑚中为 0.36 个/g，贝类中为 1.50 个/g，鱼类鳃中为 0.48 个/g，鱼类胃肠道中为 1.71 个/g。上述样本中普遍存在的微塑料特征为尺寸小于 1000 µm、纤维状和透明状，主要聚合物类型为聚对苯二甲酸乙二醇酯、聚丙烯、聚乙烯和粘胶纤维。不同珊瑚的微塑料富集能力存在差异（Pocillopora > Acropora > Sinularia）。值得注意的是，与珊瑚内部相比，微塑料在珊瑚表面更为丰富，且表现出明显的特征，包括珊瑚表面较大尺寸（>500 µm）和纤维状的聚对苯二甲酸乙二醇酯微塑料，以及珊瑚内部较小尺寸（20-200 µm）的碎片状聚乙烯微塑料。此外，研究还表明，微塑料对珊瑚的原位影响具有种间特异性，包括共生藻的光合作用、珊瑚的抗氧化和免疫活性。此外，在所研究的区域中，除了 YLW 的底层海水和表层沉积物分别表现出极端和中等风险水平外，大多数环境介质中的微塑料生态风险都较小。珊瑚的风险水平总体处于中等水平，除了 DDH 的危险水平和 LHT 的高风险水平。海南岛南部边缘珊瑚礁的微塑料潜在来源主要是旅游、住宅和渔业活动。
