Microplastic pollution has become an increasing concern. Vertical transport of microplastics is one of the major research questions concerning the distribution and fate of microplastics in the marine environment, and biologically mediated vertical transport is particularly significant. However, studies on the effects of different types of benthic organisms on the vertical distribution of microplastics in sediments are still scarce. The results of this study revealed that when exposed to environmentally relevant concentrations of fluorescent polystyrene microbeads (200 µm), Manila clams (Ruditapes philippinarum) exhibited prolonged acclimation period, yet subsequent burrowing behavior (burrowing rate and burrowing velocity) was unaffected. The condition index, clearance rate, and oxygen consumption rate of the clams similarly exhibited no stress response after 14 days of exposure. We determined that microplastics were rapidly transported to deeper layers (6–8 cm below the surface) in the sediment under bioturbation. This study elucidates the mechanisms of microplastic transport, showing that clam behaviors such as burrowing, movement, and ingestion contribute to this process. The results suggest that a biologically based management strategy may be a more environmentally friendly means of mitigating microplastic pollution in seawater.

中文翻译：

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埋藏双壳类在暴露于微塑料后的影响和行为变化


微塑料污染已成为一个日益受到关注的问题。微塑料的垂直运输是有关微塑料在海洋环境中分布和归宿的主要研究问题之一，生物介导的垂直运输尤为重要。然而，关于不同类型底栖生物对沉积物中微塑料垂直分布影响的研究仍然很少。这项研究的结果表明，当暴露于环境相关浓度的荧光聚苯乙烯微珠 （200 μm） 时，马尼拉蛤蜊 （Ruditapes philippinarum） 表现出较长的驯化期，但随后的穴居行为（穴居速度和穴居速度）不受影响。蛤蜊的状况指数、清除率和耗氧率在暴露 14 天后同样表现出无应激反应。我们确定，在生物扰动下，微塑料会迅速移动到沉积物中的更深层（地表以下 6-8 厘米）。本研究阐明了微塑料运输的机制，表明蛤蜊的挖洞、移动和摄入等行为有助于这一过程。结果表明，基于生物的管理策略可能是减轻海水中微塑料污染的更环保的手段。