Riverine systems act as converging pathways for discarded litter within drainage basins, becoming key elements in gauging the transfer of mismanaged waste into the ocean. However, riverine litter data are scarce and biased towards microplastics, generally lacking information about larger items. Based on the first ever database of riverine floating macrolitter across Europe, we have estimated that between 307 and 925 million litter items are released annually from Europe into the ocean. The plastic fraction represented 82% of the observed litter, mainly fragments and single-use items (that is, bottles, packaging and bags). Our modelled estimates show that a major portion of the total litter loading is routed through small-sized drainage basins (<100 km²), indicating the relevance of small rivers, streams and coastal run-off. Moreover, the major contribution of high-income countries to the macrolitter inputs suggests that reducing ocean pollution cannot be achieved only by improving waste management, but also requires changing consumption habits and behaviour to curb waste generation at source. The inability of countries with well-developed recovery systems to control the leakage of waste into the environment further supports the need to regulate the production and use of plastic on a global scale.

河流系统充当流域内丢弃垃圾的汇合通道，成为衡量管理不善的废物转移到海洋中的关键因素。然而，河流垃圾数据稀少且偏向于微塑料，通常缺乏关于较大物品的信息。根据有史以来第一个横跨欧洲的河流漂浮大型垃圾数据库，我们估计每年有 3.07 至 9.25 亿垃圾物品从欧洲释放到海洋中。塑料部分占观察到的垃圾的 82%，主要是碎片和一次性物品（即瓶子、包装和袋子）。我们的模型估计表明，垃圾总负荷的主要部分是通过小型流域盆地（<100 km ²)，表明小河流、溪流和沿海径流的相关性。此外，高收入国家对大型垃圾投入的主要贡献表明，减少海洋污染不能仅通过改善废物管理来实现，还需要改变消费习惯和行为，从源头上遏制废物的产生。拥有完善的回收系统的国家无法控制废物泄漏到环境中，这进一步支持了在全球范围内规范塑料生产和使用的必要性。