Occurrence of anthropogenic microdebris in stomach content from three commercial pelagic fish species off the coast of Ecuador

de Guise-Alarie M.; Mendoza L.M.R.; Luna S.A.; Pacheco A.S. · Environmental Biology of Fishes (2026) · DOI: 10.1007/s10641-026-01899-5

Resumen

Anthropogenic microdebris (AMD), including microplastics (MPs) and textile‑derived fibers, is widely distributed in marine ecosystems, yet many studies do not clearly distinguish polymer‑confirmed MPs from non‑plastic fibers. Here, we quantified AMD ingestion and characterized material composition in three commercially important pelagic fish from the coast of Ecuador: Opisthonema libertate, Auxis eudorax, and Scomber japonicus. We examined 297 fish, and isolated particles from fully digested stomach contents, then using μFTIR spectroscopy (Thermo Scientific iN10 Nicolet) to separate polymer-confirmed MPs from natural cellulosic fibers. MPs were detected in 41 individuals, corresponding to 14.68% of Opisthonema libertate, 15.09% of Scomber japonicus, and 18.75% of Auxis eudorax. These results indicate a generally low prevalence of MP ingestion across species and life stages. In contrast, most recovered AMD consisted of anthropogenic fibers, predominantly cellulosic (e.g., cotton/linen/cellulose). Particle abundance and material composition did not differ significantly among species, between juveniles and adults, or with stomach weight. Overall, these results indicate limited ingestion of MPs among the studied taxa, while highlighting widespread exposure to anthropogenic fibers likely linked to land‑based inputs, such as wastewater, along the Ecuadorian coast. These findings provide baseline evidence for AMD exposure in coastal pelagic fisheries and underscore the value of polymer‑specific identification for interpreting sources and pathways. © The Author(s), under exclusive licence to Springer Nature B.V. 2026.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Científica del Sur