Plastic pollution in oceans and rivers is of growing concern. Aquatic ecosystems play an important role in transport and storage of plastic waste from land-based storage to riverine and marine environments. This focus issue brings together new insights on the sources, transport dynamics, fate, and impact of plastic pollution through aquatic environments. The work collected in this focus issue shows that urban areas, transportation infrastructure, and wastewater treatment plants are consistently identified as sources for micro-, meso-, and macroplastics. Transport dynamics of plastics over land and through rivers were found to be driven by human factors, flood and storm events, and hydrodynamics, and combinations thereof. Most plastics were found not to make it to the open sea, but rather beach, float in coastal waters, or accumulate on land and within river systems. When exposed to the environment, both conventional and biodegradable plastics degrade into smaller pieces. Yet, the degradation and fragmentation of plastics in the environment remain unresolved. Future work should focus on transferability of new river and region specific insights, collection and exploration of large-scale and novel datasets, source and entry point identification, and understanding fundamental transport mechanisms. This focus issue provides new insights on sources, transport, fate, and impact of plastics, but also emphasizes that need for further work on plastics in aquatic ecosystems.

中文翻译：

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关注从陆地到水生生态系统的塑料

海洋和河流中的塑料污染日益受到关注。水生生态系统在塑料废物从陆上储存到河流和海洋环境的运输和储存中发挥着重要作用。这个焦点问题汇集了关于塑料污染通过水生环境的来源、运输动态、归宿和影响的新见解。本期焦点刊收集的工作表明，城市地区、交通基础设施和污水处理厂一直被确定为微塑料、中观塑料和大塑料的来源。人们发现，塑料在陆地上和河流中的运输动态是由人为因素、洪水和风暴事件、流体动力学及其组合驱动的。大多数塑料被发现并没有进入公海，而是漂浮在沿海水域的海滩上，或在陆地上和河流系统内积累。当暴露在环境中时，传统塑料和可生物降解塑料都会降解成更小的碎片。然而，塑料在环境中的降解和碎裂问题仍未解决。未来的工作应侧重于新河流和区域特定见解的可转移性、大规模和新数据集的收集和探索、源头和入口点识别以及了解基本传输机制。这一焦点问题提供了关于塑料的来源、运输、归宿和影响的新见解，但也强调需要进一步研究塑料在水生生态系统中的作用。塑料在环境中的降解和碎裂问题仍未解决。未来的工作应侧重于新河流和区域特定见解的可转移性、大规模和新数据集的收集和探索、源头和入口点识别以及了解基本传输机制。这一焦点问题提供了关于塑料的来源、运输、归宿和影响的新见解，但也强调需要进一步研究塑料在水生生态系统中的作用。塑料在环境中的降解和碎裂问题仍未解决。未来的工作应侧重于新河流和区域特定见解的可转移性、大规模和新数据集的收集和探索、源头和入口点识别以及了解基本传输机制。这一焦点问题提供了关于塑料的来源、运输、归宿和影响的新见解，但也强调需要进一步研究塑料在水生生态系统中的作用。