Marine ecosystems are reported to be contaminated by microplastics (MPs) (< 5 mm); however, the ecological mechanisms involved in the ingestion of debris by marine organisms are relatively unknown. By developing and optimising an appropriate protocol of gut digestion for fish species, this study explores a tropical estuarine environment to unriddle the processes responsible for the different ingestion rates of plastic debris. A total of 82 fishes with different feeding habits were analysed, Centropomus undecimalis (n $=$ 30; Piscivore), Bairdiella ronchus (n $=$ 21; Zoobenthivore) and Gobionellus stomatus (n $=$ 31; Detritivore). The microplastic ingestion varied with the feeding strategy; C. undecimalis, the predator, was the most contaminated species. Overall, most MPs were fibres (47%), followed by pellets (40%) and fragments (13%), although these proportions varied among species. A high level of contamination was found in the Estuarine Complex of Santa Cruz Channel, Northeast of Brazil, with many potential input sources of MPs to the estuary, which likely accumulates in the sediment and water column, with unknown consequences for human health.

据报道，海洋生态系统受到微塑料 (MP) (< 5 毫米) 的污染；然而，海洋生物摄入垃圾所涉及的生态机制相对未知。通过开发和优化适合鱼类的肠道消化方案，这项研究探索了热带河口环境，以解开导致塑料碎片不同摄入率的过程。共分析了 82 条不同摄食习性的鱼类, Centropomus undecimalis (n$=$30; Piscivore), Bairdiella ronchus (n$=$21; Zoobenthivore ) 和Gobionellus stomatus (n$=$31; 食腐动物）。微塑料的摄入因喂养策略而异；捕食者C. undecimalis是受污染最严重的物种。总体而言，大多数 MP 是纤维 (47%)，其次是颗粒 (40%) 和碎片 (13%)，尽管这些比例因物种而异。在巴西东北部圣克鲁斯海峡的河口综合体中发现了高度污染，有许多潜在的 MPs 输入源进入河口，这些物质可能会积聚在沉积物和水体中，对人类健康造成未知的后果。