In this study, we investigated microplastic contamination of the Yangtze River from the upper reaches to the estuary using different sampling methods to understand extensive information on microplastic pollution. The microplastic samples were collected at 10 sites using two conventional methods: trawling and filtering water. The results showed that the average abundance of microplastics ranged from 1.62±0.61 × 10⁵ to 4.25±3.87 × 10⁶ items/km² (trawling samples) and 800.0±300.0 to 3088.9±330.6 items/m³ (filtering water samples). The average abundance (by trawling) in the Three Gorges Reservoir (2.80±1.86 × 10⁶ items/km²) was one order of magnitude higher than that of other sections, which affirmed the barrier effect of dams on microplastic distribution. The barrier effect was more obvious on larger size particles by comparing the results of two methods. The abundances near the left, right banks, and in the midstream showed no significant difference by both two methods, illustrating that sampling at each bank along the Yangtze River was also representative in one section. Characteristics analysis demonstrated that fragments (47.9%) dominated in trawling samples and fiber (63.4%) dominated in filtering water samples. Microplastics of small sizes (<1 mm) and transparent were dominant in samples collected by the two methods. Polyethylene (PP) and polypropylene (PE) were the dominant polymer types in the detected microplastics. In this study, we provided detailed information on microplastic pollution of the Yangtze River from the upstream to the estuary, which is useful for microplastic management and control in this area.

在这项研究中，我们使用不同的采样方法调查了长江上游到河口的微塑性污染，以了解有关微塑性污染的广泛信息。使用两种常规方法在10个地点收集微塑性样品：拖网和过滤水。结果表明，微塑料的平均丰度范围为1.62±0.61×10 ⁵至4.25±3.87×10 ⁶个/ km ²（拖网样品）和800.0±300.0至3088.9±330.6个/ m ³（过滤水样品）。三峡水库的平均丰度（通过拖网捕捞）（2.80±1.86×10 ⁶项/ km ²）比其他部分高一个数量级，这肯定了大坝对微塑性分布的屏障作用。通过比较两种方法的结果，对较大尺寸的颗粒的阻隔作用更加明显。两种方法在左岸，右岸和中游附近的丰度均无显着差异，这说明沿长江沿岸各岸的采样也具有代表性。特征分析表明，拖网样品中的碎片占47.9％，过滤水样品中的纤维占63.4％。两种方法收集的样品中，小尺寸（<1毫米）和透明的微塑料占主导地位。在检测到的微塑料中，聚乙烯（PP）和聚丙烯（PE）是主要的聚合物类型。在这项研究中，