Distribution, abundance, and diversity of microplastics in the upper St. Lawrence River
Distribution, abundance, and diversity of microplastics in the upper St. Lawrence River
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DOI：
10.1016/j.envpol.2020.113994
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发表时间：
2020-05-01
影响因子：
8.9
通讯作者：
Ricciardi, Anthony
中科院分区：
文献类型：
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作者：
Crew, Alex;Gregory-Eaves, Irene;Ricciardi, Anthony
微塑料是淡水中普遍存在的污染物，但它们在河流环境中的分布、丰度和多样性仍然鲜有记录。先前的研究表明，圣劳伦斯河的淡水沉积物中含有丰富的大型聚乙烯微珠。在这里，我们通过量化沉积物和地表水样本中各种尺寸和类型的微塑料的丰度来扩展这项工作，并将这些指标与环境变量联系起来。 2017 年 7 月至 8 月，我们对蒙特利尔和魁北克市之间圣劳伦斯河河流走廊沿线的 21 个跨越土地利用梯度的沉积物地点以及废水排放点上方和下方的 10 个地表水站进行了采样。使用石油提取方案从沉积物中去除了微塑料，并在荧光显微镜下进行了计数。我们测试了环境过滤器和已知点源影响河流中微塑料浓度的预测。所有沉积物采样点的微塑料平均浓度为每公斤干重 832 个（+/- 150 SE）塑料（每公斤干重 65-7562 个塑料），这是世界淡水和海洋系统有记录的最高浓度之一（前 25%）。沉积物中的微塑料浓度与一系列环境变量显着相关，包括土地利用和沉积物颗粒特征。颗粒特征、与点源的接近程度（城市土地利用）和环境过滤器（沉积物成分变量、有机碳百分比、无机碳百分比和距海岸的距离）均解释了沉积物中微塑料成分的很大一部分变化，其中环境过滤器的影响最大。我们提出了一种协议，可用于高效、准确地检测各种微塑料，直到建立用于大规模监测的标准化协议。 (C) 2020 Elsevier Ltd. 保留所有权利。
Microplastics are pervasive pollutants in fresh waters, but their distribution, abundance, and diversity in fluvial environments remain poorly documented. Previous research indicated that large polyethylene microbeads were abundant in the freshwater sediments of the St. Lawrence River. Here we extend this work by quantifying the abundance of a broad range of sizes and types of microplastics in sediments and surface water samples, and we relate these metrics to environmental variables. We sampled 21 sites for sediments that spanned a land use gradient, and 10 surface water stations above and below wastewater effluent sites, along the fluvial corridor of the St. Lawrence River between Montreal and Quebec City from July to August 2017. Microplastics were removed from sediments using an oil extraction protocol and enumerated under fluorescent microscopy. We tested predictions that environmental filters and known point sources affect microplastic concentrations in the river. The mean concentration of microplastics across all sediment sampling sites was 832 (+/- 150 SE) plastics per kg dry weight (range 65-7562 plastics per kg dry weight), which is among the highest recorded (in the top 25%) for the world's freshwater and marine systems. Microplastic concentrations in the sediments were significantly related to a suite of environmental variables including land use and sediment particle characteristics. Particle characteristics, proximity to point sources (urban land use), and environmental filters (sediment compositional variables, % organic carbon, % inorganic carbon and distance from shore) each explained a significant fraction of variation in the microplastic composition in the sediment, with environmental filters having the greatest influence. We present a protocol that could be used to efficiently and accurately detect a broad range of microplastics until a standardized protocol is established for large-scale monitoring. (C) 2020 Elsevier Ltd. All rights reserved.