Macroinvertebrate ecosystem engineering affects streambed retention of microplastics
Macroinvertebrate ecosystem engineering affects streambed retention of microplastics
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DOI：
10.1086/724584
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发表时间：
2023-06-01
影响因子：
1.8
通讯作者：
Poole，Geoffrey C.
中科院分区：
文献类型：
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作者：
Fritz，Samuel F.;Albertson，Lindsey K.;Poole，Geoffrey C.
水生环境的微塑料污染威胁着人类健康、生态系统过程和生物多样性。许多现有的微塑料在溪流中运动的模型没有考虑生物对微塑料命运的影响。网纺石蛾（Hydropsychidae）的生态系统工程已被证明可以极大地影响沉积物和有机物的运输以及河床水文。石蚕工程同样可能影响溪流中微塑料污染物的移动。我们使用 11 天的受控水槽实验来研究石蛾作为微塑料运输生物控制的潜力。含有单个砾石沙丘的水槽被随机分配到密度处理：对照（0 石蛾/平方米）或储存 500、800 或 2500 石蛾/平方米，孵化（d 1-10）以允许石蛾丝结构构建，用 PVC 微塑料（333 µm-1 mm）接种（d 11），并采样（d 12）。微塑料被量化为被流网捕获（下游运输）、被石蛾吃掉（摄入）、被石蛾丝结构捕获或沉入砾石沙丘（即总河床滞留）。 800 只石蚕/平方米处理中的平均下游塑料运输比对照低 9%（p < 0.001），2500 只石蚕/平方米处理中则低 10%（p = 0.003）。在 800 只石蚕/平方米处理中，平均总河床滞留量比对照高 9%（p < 0.001），在 2500 只石蚕/平方米处理中高出 10%（p = 0.004）。石蛾摄入塑料的情况很少且变化很大（塑料颗粒的 0-0.55%），但确实随着石蛾密度的增加而增加（p= 0.002）。这项工作代表了动物生态系统工程作为控制淡水中微塑料颗粒的运动和命运的首批研究之一，并为未来微塑料运输的生物控制研究奠定了基础。我们的结果表明，通过结网石蛾进行的生态系统工程可以作为淡水溪流中微塑料运输的生物控制。
Microplastic pollution of aquatic environments threatens human health, ecosystem processes, and biodiversity. Many existing models of microplastic movement in streams do not account for biotic effects on microplastic fate. Ecosystem engineering by net-spinning caddisflies (Hydropsychidae) has been shown to substantially affect sediment and organic matter transport as well as streambed hydrology. Caddisfly engineering may likewise affect the movement of microplastic pollution in streams. We used a controlled 11-d flume experiment to investigate the potential for caddisflies to serve as a biotic control on microplastic transport. Flumes containing a single gravel dune were randomly assigned to density treatments: control (0 caddisflies/m2) or stocked with 500, 800, or 2500 caddisflies/m2, incubated (d 1–10) to allow for caddisfly silk structure construction, inoculated (d 11) with PVC microplastics (333 µm–1 mm), and sampled (d 12). Microplastic was quantified as caught in a drift net (downstream transport), eaten by caddisflies (ingestion), or captured in caddisfly silk structures or settled into the gravel dune (i.e., total streambed retention). Mean downstream plastic transport was 9% lower than the control in the 800 caddisflies/m2treatment (p< 0.001) and 10% lower in the 2500 caddisflies/m2treatment (p= 0.003). Mean total streambed retention was 9% higher than the control in the 800 caddisflies/m2treatment (p< 0.001) and 10% higher in the 2500 caddisflies/m2treatment (p= 0.004). Ingestion of plastic by caddisflies was rare and highly variable (0–0.55% of plastic particles) but did increase with caddisfly density (p= 0.002). This work represents one of the first investigations of animal ecosystem engineering as a control on the movement and fate of microplastic particles in fresh waters and establishes a foundation for future research on biotic control of microplastic transport. Our results suggest that ecosystem engineering by net-spinning caddisflies may serve as a biotic control of microplastic transport in freshwater streams.