An assessment of microplastics in the ecosystem and selected commercially important fishes off Kochi, south eastern Arabian Sea, India.

A preliminary report on the abundance of microplastic in the coastal waters in the depth zone 5 to 20 m in the surface waters, sediment and in selected fishes occurring off Kochi, India is presented. Spatial and temporal variation in microplastic abundance was observed with higher abundance in surface water indicating threats to pelagic ecosystem. The relative concentration of microplastic was highest during monsoon season. The major microplastics were fragments of 1-5 mm in white and blue colours. Gut content analysis of 16 species (653 individuals) comprising pelagic (8 species) and demersal (8 species) indicated occurrence (4.6%) of microplastics (fragment>filament>pellet) of size 0.27mm to 3.2 mm in Sardinella longiceps, S. gibbosa, Stolephorus indicus Rastrelliger kanagurta and Cyanoglossus macrostomus. Raman spectroscopy indicated that Polyethylene (PE) and Polypropylene (PP) were the polymer types of microplastics from the fish gut.