Laboratory of Marine Ecological Environment Early Warning and Monitoring, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
Xiamen Institute of Environmental Science, Xiamen 361021, China.
Sci Total Environ. 2023 Feb 25;861:160562. doi: 10.1016/j.scitotenv.2022.160562. Epub 2022 Nov 28.
Land-based transport from nearshore areas is a key pathway of microplastic (MP) pollution in the oceans. Therefore, transport, fate, and intervention on MPs necessitate an investigation of MP contamination in coastal regions. Here, MP pollution in the surface waters of Xiamen Bay and Jiulong River estuary was evaluated in 2021 after the outbreak of COVID-19. The abundance of MPs in Xiamen Bay ranged from 0.20 to 5.79 items m with an average of 1.03 items m, whereas that in the Jiulong River estuary spanned from 0.55 to 2.11 items m with a mean of 1.30 items m. A yearly decreasing trend in the abundance of MPs in surface waters in both regions was observed. The particle sizes of MPs were concentrated in the range of 2.50-5.00 mm, and the colors were mainly white, transparent, and green. The micro-Raman spectroscopic results showed that MP polymer types were predominantly polyethylene, polypropylene, and polystyrene. A lower abundance of MPs in Xiamen Bay with no obvious pattern was observed, while that in the Jiulong River estuary showed a wavelike distribution from upstream to downstream. Ecological risk assessment of MP pollution in surface waters of two regions was performed using the pollution load index (PLI), giving the risk level in descending order: wastewater discharge area > aquaculture area > sloughs > estuary mouth > estuarine rivers > shipping lane. The average risk level of Xiamen Bay (I) was lower than that in Jiulong River estuary (II). The MP pollution in the Jiulong River estuary appeared heavier than that in Xiamen Bay, which may be due to the combined effects of COVID-19 and marine governance. This study provided insights into the prevention and management of MP pollution in nearshore semi-enclosed bays.
陆源传输是海洋中微塑料（MP）污染的主要途径之一。因此，需要对 MPs 的传输、归宿和干预进行研究，以了解沿海地区的 MP 污染情况。本研究于 2021 年新冠疫情爆发后，评估了厦门湾和九龙江口海域的表层水微塑料污染。厦门湾海域 MPs 的丰度范围为 0.20-5.79 个/立方米，平均值为 1.03 个/立方米；九龙江口海域 MPs 的丰度范围为 0.55-2.11 个/立方米，平均值为 1.30 个/立方米。两个海域的 MPs 丰度均呈现出逐年下降的趋势。MP 粒径主要集中在 2.50-5.00mm 之间，颜色主要为白色、透明和绿色。微拉曼光谱分析结果表明，MP 的聚合物类型主要为聚乙烯、聚丙烯和聚苯乙烯。厦门湾海域的 MPs 丰度较低，且无明显分布规律，而九龙江口海域则呈现出从上游到下游的波浪状分布。本研究采用污染负荷指数（PLI）对两个海域的表层水 MP 污染进行了生态风险评估，风险等级依次为：污水排放区>水产养殖区>滩涂>河口>河口河流>航道。厦门湾的平均风险等级（I）低于九龙江口（II）。九龙江口的 MP 污染似乎比厦门湾更严重，这可能是由于新冠疫情和海洋治理的综合影响。本研究为近岸半封闭海湾的 MP 污染防治提供了参考。
