Accumulation of microplastic in edible marine species from North Kerala, India

Microplastics in edible seafood constitute a significant concern, as they can accumulate in the tissues of marine organisms and entering food chain through which it reaches human and cause health risks. This study aims to investigate the presence of microplastics in the edible tissues of Marcia opima, Metapenaeus dobsoni, and Stolephorus indicus, collected from the central fish markets in Kasargod District of Kerala, India. About 9 kg of seafood (3 kg of each species) was collected from three major fish markets. From this, 50 species samples were randomly selected, totalling 150 samples representing each sample. About 193 microplastics from 150 individuals of three different seafood species were isolated and identified. Metapenaeus dobsoni was found to have the greatest number of microplastics (155) among these three species. Microplastic fibres constituted a significant part of total microplastic counts. Microplastic identification was made using a 'Leica stereo-zoom binocular microscope'; confirmation and polymer identification were made using the FTIR-ATR method. Six different polymers were identified such as polyethylene, polyethylene terephthalate, polyvinyl chloride, polyester, polytetrafluoroethylene, and polyacrylamide. Among these, microplastic analysis across all three species showed that nearly half were composed of polyethylene, with polyethylene terephthalate being the second most prevalent polymer. Additionally, Metapenaeus dobsoni has been newly reported globally as a species with microplastic contamination.