Microplastics in Juvenile Commercial Fish from an Estuarine Environment

Microplastic ingestion has been reported by a range of marine fish species, but less known is the level of microplastic contamination by fish species from transitional ecosystems such as estuaries. The aim of this study was to assess the ingestion of microplastics by three important commercial fish species: the sea bass (Dicentrarchus labrax), the commom two-banded seabream (Diplodus vulgaris) and the European flounder (Platichthys flesus) from the Mondego estuary (Portugal). Microplastics were extracted from the gastrointestinal tract of 120 individuals after a digestion solution (10% KOH). A total of 157 microplastics were extracted from the total fish (96% fibers and 4% fragments), with 1.67 ± 0.27 (SD) microplastics per fish. The main plastic polymers identified by μ-FTIR were polyethylene, polypropylene, rayon, polyester, polyacrylonitrile and nylon.