Anthropogenic debris including microparticles (<5 mm) are ubiquitous in marine environments. The Salish Sea experiences seasonal fluctuations in precipitation, river discharge, sewage overflow events, and tourism—all variables previously thought to have an impact on microparticle transport and concentrations. Our goals are two-fold: 1) describe long-term microparticle contamination data including concentration, type, and size; and 2) determine if seasonal microparticle concentrations are dependent on environmental or tourism variables in Elliott Bay, Salish Sea. We sampled 100 L of seawater at a depth of approximately 9 m at the Seattle Aquarium, Seattle, Washington State, United States, approximately every two weeks from 2019 through 2020 and used an oil extraction protocol to separate microparticles. We found that microparticle concentrations ranged from 0 to 0.64 particles L⁻¹ and fibers were the most common type observed. Microparticle concentrations exhibited a breakpoint on 10 April 2020, where estimated slope and associated microparticle concentration significantly declined. Further, when considering both environmental as well as tourism variables, temporal microparticle concentration was best described by a mixed-effects model, with tourism as the fixed effect and the person counting microparticles as the random effect. Although monitoring efforts presented set out to identify effects of seasonality and interannual differences in microparticle concentrations, it instead captured an effect of decreased tourism due to the global Covid-19 pandemic. Long-term monitoring is critical to establish temporal microparticle concentrations and to help researchers understand if there are certain events, both seasonal and sporadic (e.g., rain events, tourism, or global pandemics), when the marine environment is more at risk from anthropogenic pollution. Environ Toxicol Chem 2022;41:917–930. © 2021 Seattle Aquarium. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

中文翻译：

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华盛顿州西雅图水族馆下微粒的时间变化：记录全球 Covid-19 大流行

包括微粒（<5 毫米）在内的人为碎片在海洋环境中无处不在。萨利希海经历了降水、河流排放、污水溢出事件和旅游业的季节性波动——所有这些变量以前都被认为会对微粒的运输和浓度产生影响。我们的目标有两个：1) 描述长期的微粒污染数据，包括浓度、类型和大小；2) 确定季节性微粒浓度是否取决于萨利希海艾略特湾的环境或旅游变量。从 2019 年到 2020 年，我们大约每两周在美国华盛顿州西雅图的西雅图水族馆对 9 m 深度的 100 L 海水进行采样，并使用油提取方案分离微粒。^-1纤维是观察到的最常见的类型。微粒浓度在 2020 年 4 月 10 日出现断点，估计斜率和相关微粒浓度显着下降。此外，当同时考虑环境和旅游变量时，时间微粒浓度最好用混合效应模型来描述，旅游是固定效应，而计数微粒的人数是随机效应。尽管提出的监测工作旨在确定微粒浓度的季节性和年际差异的影响，但它却捕捉到了由于全球 Covid-19 大流行而导致的旅游业减少的影响。长期监测对于确定时间微粒浓度和帮助研究人员了解是否存在某些事件至关重要，环境毒物化学2022；41：917–930。© 2021 西雅图水族馆。Wiley Periodicals LLC 代表 SETAC 出版的Environmental Toxicology and Chemistry 。