We quantify plastic litter (PL, > 2 cm) and microplastics (MP, < 5 mm) from the sediments of a beach formed at a riverine depositional area, at the upper Amazon River basin, Ecuador. In the collection area (4400 m²), the PL density was 0.045 items m⁻², where low-density polyethylene bags were the prevalent PL. The beach was classified as “very clean” (Clean Coast Index (CCI) of 1.3 items m⁻²). Regarding MP, in 55 sampling stations, average MP concentrations ranged from 0 to 2200 items kg⁻¹ of dry sediment (0.5–2 mm), and 0–4200 items kg⁻¹ of dry sediment (2–5 mm). Blue fibers were the prevalent MP. Our results represent the first report to show the ubiquitous presence of PL and MP for the area. The monitoring and management of plastic disposal in freshwater beaches are necessary, as here we report a small part of an undocumented issue.

我们量化了厄瓜多尔亚马逊河流域上游河流沉积区形成的海滩沉积物中的塑料垃圾 (PL, > 2 cm) 和微塑料 (MP, < 5 mm)。在收集区（4400 m ²），PL 密度为0.045 件m ^-2，其中低密度聚乙烯袋是普遍的PL。该海滩被归类为“非常干净”（清洁海岸指数 (CCI) 为 1.3 项 m ^-2）。关于 MP，在 55 个采样站，平均 MP 浓度范围为 0 至 2200 项 kg ^-1的干沉积物（0.5-2 毫米）和 0-4200 项 kg ^-1干沉积物（2-5 毫米）。蓝色纤维是流行的 MP。我们的结果是第一份显示该地区 PL 和 MP 无处不在的报告。淡水海滩塑料处理的监测和管理是必要的，因为我们在这里报告了一个未记录问题的一小部分。