Identification of Certain Microplastic Species in Pelagic and Demersal Fish in the Black Sea

In this study, it was aimed to determine the occurrence, concentration and polymer types of microplastics in the stomach, intestine and gill tissues of pelagic fish species including bonito (Sarda sarda), horse mackerel (Trachurus mediterraneus), and anchovy (Engraulis encrasicolus), as well as demersal fish species including red mullet (Mullus barbatus) and whiting (Merlangius merlangus) from the Black Sea. A total of 150 fish samples (30 individuals from each species) were analyzed. Stomach, intestine and gill tissues were collected and prepared for microplastic analysis, and polymer identification was performed using Fourier Transform Infrared Spectroscopy (FTIR). Microplastics were detected in a considerable proportion of the examined individuals. In pelagic fish species, the most common polymers identified were polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). In stomach tissues, PE (29%) and PVC (29%) were the dominant polymer types. In intestinal tissues, PP (35%) and PE (27%) were most prevalent, while in gill tissues PP (24%) and PE (22%) were the most frequently detected polymers. In demersal fish species, the dominant microplastic polymers were also PP and PE. In stomach tissues, PP (22%) and PE (17%) were most common, while intestinal tissues contained PP (25%) and PE (21%). In gill tissues, PP (23%) and PE (21%) were the most abundant polymers detected. The results indicate that both pelagic and demersal fish species in the Black Sea are exposed to microplastic contamination, with notable differences in polymer composition among tissues. These findings highlight the widespread presence of microplastics in commercially important fish species and emphasize the potential ecological and food safety implications of microplastic pollution in the Black Sea ecosystem.