Microplastics in vulnerable catfish: baseline data from northern Patagonia’s Genidens barbus

Abstract

Microplastics (MPs) contamination in aquatic ecosystems poses a rising environmental challenge with impacts on biota. This study provides the first assessment of MPs ingestion by the vulnerable Genidens barbus (white sea catfish) species in northern Patagonia, Argentina, aiming to evaluate their presence, abundance, type, and potential sources across two contrasting sites: Río Negro estuary (RNe) and San Blas Bay (SBb). MPs were extracted from stomachs with 10 % KOH digestion (48 h) and classified by size, type, and color, and characterized using micro Attenuated Total Reflectance-Infrared (μ-ATR) spectroscopy. Results show a high incidence of MPs, with 93 % of fish containing MPs (mean: 19 ± 17 items/fish), predominantly fibers (0.5–1.5 mm). No spatial differences were detected (mean values: 0.051 items g−1 in RNe and 0.057 items g−1 in SBb) and nor correlations with fish size. Chemical characterization revealed cellulose, polyethylene terephthalate, polypropylene, cotton-polyamide, polyacrylic, and alkyd resin, highlighting urban wastewater and fishing activities as probable sources. This study establishes baseline data of MPs pollution in G. barbus, a key fishery resource, and underscores the urgency of monitoring estuarine systems to mitigate impacts on vulnerable species.