Microplastic abundance in commercially important brackish water fin-fish from the Bay of Bengal

Microplastics (MPs) are prevalent contaminants found in marine ecosystems worldwide. This study investigates the occurrence of microplastic contamination in the gastrointestinal tracts of several commercially significant brackish water fin-fish from the Bay of Bengal. Seven brackish water fish species Bombay-duck (Harpadon nehereus), Amadi (Coilia reynaldi), Bhola Bhetki (Nibea soldado), Silver Pomfret (Pampus argenteus), Goldspot mullet (Planiliza parsia), Horse Mackerel (Megalaspis cordyla), and Fringe scale sardinella (Sardinella fimbriata) were sourced from two major fish markets in Kolkata. Fish digestive tracts were dissected and incubated in potassium hydroxide, then subjected to density separation using sodium chloride. Supernatants were vacuum-filtered, dried, and examined under a stereomicroscope. The hot needle test confirmed the presence of microplastics. Harpadon nehereus exhibited the highest contamination (6.5 ± 2.56 MP/individual). Fibers were the most common microplastic type, and red was the predominant color. These findings imply trophic transfer and potential ecological and human health risks, exacerbated by poor waste management. Further research is required to elucidate the full scope of ecological and health implications.