Occurrence of microplastics in the gastrointestinal tracts of some edible fish species along the Turkish coast

Abstract

Plastics have become an inseparable part of modern life as a consequence of their versatility, low cost, durability, and lightweight. In this study, the presence of microplastics (MPs) in the stomachs and digestive tracts of 243 individuals of leaping mullet(Chelon saliens (Risso, 1810)), red mullet (Mullus barbatus barbatus Linnaeus, 1758), surmullet (Mullus surmuletus Linnaeus, 1758),Mediterranean horse mackerel (Trachurus mediterraneus (Steindachner, 1868)), and sand steenbras (Lithognathus mormyrus (Linnaeus,1758)), collected along the Marmara, Aegean, and Mediterranean coasts of Turkey was examined microscopically and through µ-Ramananalysis. A total of 283 MP particles were extracted. Among the examined species, the average MP concentration was 1.1 MP perfish (MPs $fish^{-1}$). The number of MPs detected was 2.5 MPs $fish^{-1}$ for leaping mullet, 1.1 MPs $fish^{-1}$ for red mullet, 0.6 MPs fish–1 forsand steenbras, and 0.4 MPs $fish^{-1}$ for Mediterranean horse mackerel and surmullet. The size of the MPs ranged from 0.028 to 4.909mm. To determine the polymer types of the MPs, a μ-Raman analysis was conducted. The most frequently detected polymers werepolypropylene (26%), polyethylene (21.9%), polyethylene terephthalate/polyester (8.2%), and cellulose (7.5%). The results of this studyshowed that MP pollution represents an emerging threat to the fish of Turkish marine waters.