Microplastics in the benthic fish from the Canadian St. Lawrence River and Estuary: Occurrence, spatial distribution and ecological risk assessment

作者：A. H. M. Enamul Kabir, Elisa Michon, Marc Mingelbier, Dominique Robert, Youssouf Djibril Soubaneh, Huixiang Xie, Zhe Lu · 发表于：Marine Pollution Bulletin · 年份：2025 · DOI：10.1016/j.marpolbul.2024.117509 · 被引用次数：16 · 研究领域：Microplastics and Plastic Pollution、Recycling and Waste Management Techniques、biodegradable polymer synthesis and properties

Microplastic contamination in the St. Lawrence River and Estuary (SLRE), Canada, poses potential risks to aquatic species. However, limited understanding of microplastic contamination in benthic fish, potentially more vulnerable than pelagic species, impedes effective risk assessment in this crucial ecosystem. This study addressed knowledge gaps by analyzing microplastics in the gastrointestinal tracts (GIT) and gills of Channel Catfish (Ictalurus punctatus) and Atlantic Tomcod (Microgadus tomcod) in the SLRE. Forty-two fish from ten stations were examined using KOH digestion, density separation, wet-peroxidation, and spectroscopy. Results indicated an average abundance of 3.0 ± 0.4 (mean ± SE) microplastic particles per individual fish. Most detected particles were small microplastics (<809 μm) and fibers, with blue and transparent colors. Major polymers identified included polyethylene terephthalate and polyethylene. While catfish showed higher microplastic abundances per individual than tomcod, data based on GIT weight do not support microplastic biomagnification in this predator-prey relationship. Catfish from downstream of Québec City showed elevated levels of microplastics and more variations in their characteristics compared to average abundance found from a site located 50 km upstream. Urban activity may increase microplastic accumulation in downstream benthic fish and others. This highlights the need for further studies on the migratory capacities of fish species. Ec...