Chen Hongyu, Cheng Yu, Wang Ying, Ding Yongcheng, Wang Chenglong, Feng Xuguang, Fan Qinya, Yuan Feng, Fu Guanghe, Gao Bingfei, Liu Kai, Zou Xinqing
School of Geography and Ocean Science, Nanjing University, Nanjing 210093, China; Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing 210093, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210093, China.
Geological Survey of Jiangsu Province, Nanjing 210018, China.
Sci Total Environ. 2024 Mar 25;918:170554. doi: 10.1016/j.scitotenv.2024.170554. Epub 2024 Feb 2.
The transport of microplastics (MPs) is susceptible to being influenced by catchment hydrology; however, there is a notable lack of research on their retention and responses to flood events in estuarine sedimentary records. Herein, we collected two cores in the Yangtze Estuary to explore their microplastic pollution, influencing factors and linkage to flood events. MP abundance exhibited a decreasing trend from the top to the bottom in both cores. Both plastic production and sediment mean grain size showed a significant positive correlation with MP abundance. The sedimentary record displayed a marked surge in MP abundance during the extreme flood period, suggesting a direct influence of flooding on MP deposition. The resuspension of upstream MPs and erosion of land-based MPs by heavy rain might be responsible for this increase. Furthermore, our study identified significant periodicities in MP abundance, closely aligned with the hydrological patterns of the Yangtze River. This study highlights the role of floods in fluvial MP distribution and proposes MPs as a proxy of extreme floods from the 20th century in estuarine environments.
微塑料（MPs）的输运容易受到流域水文的影响；然而，关于它们在河口沉积记录中的滞留情况以及对洪水事件的响应，目前明显缺乏研究。在此，我们在长江口采集了两个岩芯，以探究其微塑料污染、影响因素以及与洪水事件的联系。两个岩芯中的微塑料丰度均呈现出从顶部到底部逐渐降低的趋势。塑料产量和沉积物平均粒径与微塑料丰度均呈现出显著的正相关关系。沉积记录显示，在极端洪水期微塑料丰度显著激增，这表明洪水对微塑料沉积有直接影响。上游微塑料的再悬浮以及暴雨对陆源微塑料的侵蚀可能是导致这种增加的原因。此外，我们的研究确定了微塑料丰度存在显著的周期性，与长江的水文模式密切相关。本研究突出了洪水在河流微塑料分布中的作用，并提出微塑料可作为20世纪河口环境中极端洪水的一个指标。
