Wootton, Nina, Vinuri Silva, Danielle Giuretis, Patrick Reis-Santos, Bronwyn M. Gillanders. 2025. Marine and Freshwater Research.

Context. Microplastics have been found in aquatic ecosystems globally, including in many marine organisms. Despite this, understanding the occurrence of microplastics in seafood products prepared for human consumption has received less attention. Aims. This study aims to determine the abundance and type of microplastic in dried and fresh fish purchased from seafood markets. Methods. Four locally harvested species of anchovies and sardines were sampled from seafood markets across Sri Lanka. These pelagic species are popular seafood items and are commonly consumed whole. We analysed fresh (gastrointestinal tracts, and whole body) and dried fish (whole body) under the microscope for microplastic presence (>38 μm, < 5mm), followed by polymer validation. Key results. Across all fish sampled (N=215), 82.3% had microplastic (3.64  0.26 MPs/ind), with fibre shaped pieces making up more than 95% of all microplastic particles. Overall, contamination was higher in fresh fish compared to whole dried fish. And, acrylic resin was the most common polymer. Conclusions. Microplastics were found in nearly all fresh fish and almost half the dry fish from Sri Lanka, confirming the pervasive nature of microplastic contamination. Implications. Differences in contamination levels in popular seafood products demonstrate how preparation and consumption habits can influence microplastic intake.