Assessment of microplastic pollution in eleven commercial fish species in the Gulf of İzmir (Aegean Sea, eastern Mediterranean).

With global plastic production reaching 400 million tons in 2022, concerns about plastic pollution in the seas are increasing day by day. Therefore we focused on the abundance, characteristics, and chemical composition of potential anthropogenic origin MPs within the gastrointestinal tracts (GITs) of 11 commercial fish species in the Gulf of İzmir, an area heavily impacted by human activities. Within the scope of the study, 152 fish were sampled, and microplastics were found in 64 fish. In total, 77 MPs were identified based on ATR-FTIR analysis. Significant differences were found between species regarding MP abundance. Among the species, Scomber scombrus showed the highest MP ingestion. The MP abundance in the GIT of fish decreases from surface to deeper waters. There were also significant differences (p < 0.05) in MP abundance between pelagic and demersal fish species. Results showed that 50.6 % of MPs were fragments, and 49.4 % were fibers. The most common color was black. Seven polymer types were identified, and PE was the most common. The size of the identified MPs ranged from 101 to 4901 μm, and the average value was 715.83 ± 860.66 μm. This study sheds light on the MP contamination within commercial fish species in the Gulf of İzmir and emphasizes the urgent need for enhanced marine ecosystem conservation strategies. Our findings can serve as a basis for future studies by providing essential baseline data for implementing necessary policies and regulations.