Wu Fengrun, Zhang Chengyi, Li Xueyan, Liu Sha, Wang Jinpu, Huang Weiqi
School of Environmental Science and Engineering, Xiamen University of Technology, Xiamen 361024, China.
Toxics. 2025 Jun 12;13(6):494. doi: 10.3390/toxics13060494.
Mangrove ecosystems, serving as critical barriers at land-sea interfaces, face increasing threats from microplastic pollution. This study investigates the spatial distribution, diversity, and ecological risks of microplastics in sediments from the Zhangjiang Estuary mangroves, in southeastern China. Sampling was conducted along two gradients: upstream-downstream and interior-edge habitats. The results revealed an average microplastic abundance of 219.5 ± 21.7 items·kg, dominated by fragments (53.3%) and fibers (35.0%). Additionally, 27.8% of the particles were in the 63-200 μm range, while 38.3% fell within the 200-500 μm range. A longitudinal decline in abundance from upstream to downstream was observed. Meanwhile, interior habitats exhibited significantly higher microplastic accumulation (292.86 ± 31.49 items·kg) than edge zones (142.50 ± 17.87 items·kg) ( < 0.05). The diversity index decreased downstream, with higher diversity in interior habitats, likely due to reduced terrestrial microplastic inputs and stronger tidal sorting in those areas. The ecological risk assessments indicated lower risks in Zhangjiang mangroves compared to global counterparts, though risks were elevated in interior habitats due to higher abundances of hazardous polymers (PVC, PS, PE). This study highlights the role of mangroves as microplastic sinks and advocates for multidimensional risk assessments integrating physical characteristics to guide conservation strategies in vulnerable estuarine ecosystems.
红树林生态系统作为陆海界面的关键屏障，正面临着微塑料污染日益增加的威胁。本研究调查了中国东南部漳江口红树林沉积物中微塑料的空间分布、多样性和生态风险。沿着上游-下游和内部-边缘栖息地两个梯度进行采样。结果显示，微塑料的平均丰度为219.5±21.7个·千克，以碎片（53.3%）和纤维（35.0%）为主。此外，27.8%的颗粒粒径在63-200微米范围内，而38.3%在200-500微米范围内。观察到从上游到下游丰度呈纵向下降。同时，内部栖息地的微塑料积累量（292.86±31.49个·千克）显著高于边缘区域（142.50±17.87个·千克）（<0.05）。多样性指数下游降低，内部栖息地多样性更高，这可能是由于这些区域陆地微塑料输入减少以及潮汐分选作用更强。生态风险评估表明，与全球其他地区相比，漳江口红树林的风险较低，不过由于有害聚合物（PVC、PS、PE）丰度较高，内部栖息地的风险有所升高。本研究强调了红树林作为微塑料汇的作用，并倡导进行整合物理特征的多维度风险评估，以指导脆弱河口生态系统的保护策略。
