Microplastic shape influences fate in vegetated wetlands
Microplastic shape influences fate in vegetated wetlands
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微塑料形状影响植被湿地的命运
DOI：
10.1016/j.envpol.2024.123492
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发表时间：
2024
影响因子：
8.9
通讯作者：
McIlwraith H
中科院分区：
文献类型：
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作者：
McIlwraith H
沿海地区由于靠近陆源，容易出现塑料堆积。沿海植被栖息地（如海草、盐沼、红树林）提供了无数的生态系统功能，如侵蚀保护、栖息地避难和碳储存。这些功能背后的生物和物理因素可能提供额外的好处：捕获海洋微塑料。虽然微塑料在沿海植被沉积物中的出现有充分的记录，但关于植被的存在是否会增加相对于裸露地点的微塑料捕获，以及影响微塑料捕获的因素仍未得到充分研究，存在相互矛盾的证据。我们研究了模拟滨海湿地中植被结构和微塑料类型对捕获的影响。通过水槽实验，我们测量了在枝状和草状植被存在的情况下微塑料捕获的效率，并测试了一系列形状、大小和聚合物不同的微塑料。我们观察到，植被的存在不影响捕获的微塑料的数量，但确实影响沉积的位置。微塑料的形状，而不是聚合物，是决定微塑料是否被保留在沉积物中或附着在植被冠层上的主要因素。在整个冠层中，微纤维浓度从前缘到内部下降，这表明即使在小范围内，植被也有过滤作用。这项研究的结果丰富了我们对沿海植被作为微塑料汇的理解，并且微塑料之间的差异告诉了它们最有可能在生物冠层中积聚的位置。
Coastal areas are prone to plastic accumulation due to their proximity to land based sources. Coastal vegetated habitats (e.g., seagrasses, saltmarshes, mangroves) provide a myriad of ecosystem functions, such as erosion protection, habitat refuge, and carbon storage. The biological and physical factors that underlie these functions may provide an additional benefit: trapping of marine microplastics. While microplastics occurrence in coastal vegetated sediments is well documented, there is conflicting evidence on whether the presence of vegetation enhances microplastics trapping relative to bare sites and the factors that influence microplastic trapping remain understudied. We investigated how vegetation structure and microplastic type influences trapping in a simulated coastal wetland. Through a flume experiment, we measured the efficiency of microplastic trapping in the presence of branched and grassy vegetation and tested an array of microplastics that differ in shape, size, and polymer. We observed that the presence of vegetation did not affect the number of microplastics trapped but did affect location of deposition. Microplastic shape, rather than polymer, was the dominant factor in determining whether microplastics were retained in the sediment or adhered to the vegetation canopy. Across the canopy, microfibre concentrations decreased from the leading edge to the interior which suggests that even on a small-scale, vegetation has a filtering effect. The outcome of this study enriches our understanding of coastal vegetation as a microplastics sink and that differences among microplastics informs where they are most likely to accumulate within a biogenic canopy.