Microplastic Contamination in Freshwater Fish: First Insights from Gelingüllü Reservoir (Türkiye)

Abstract The present study investigates microplastic (MP) contamination in the gills and gastrointestinal tract (GIT) of common carp ( Cyprinus carpio), mirror carp (Cyprinus carpio carpio) and European perch ( Perca fluviatilis) specimens obtained from Gelingüllü Reservoir (Türkiye). MP particles were found in 58 (75.3%) of the 77 fish examined. The percentages of MP contamination identified in the GITs of common carp, mirror carp, and perch were 46.4% (1.2 ± 1.8 MPs/ind.), 30% (0.5 ± 0.9 MPs/ind.), and 47.4% (0.9 ± 1.1 MPs/ind.), respectively. The differences observed between the three groups were not statistically significant ( p > 0.05). On the other hand, the percentages of MP contamination identified in the gills of common carp, mirror carp, and perch were 46.4% (0.7 ± 0.9 MPs/ind.), 53.3% (0.7 ± 0.8 MPs/ind.), and 68.4% (0.8 ± 0.7 MPs/ind.), respectively ( p > 0.05). There was no statistically significant effect of habitat preference or diet on MP contamination ( p > 0.05). The most frequently observed colours in the gills and GIT were blue and black. The most common size category identified in all samples was 0–100 µm, while the 100–200 µm category was predominantly observed only in the common carp gill samples. In addition, all particles observed were fibers, except for the common carp gill sample where 78.9% were fibers and the remaining 21.1% were fragments. The identified spectra were determined to be 50% polystyrene, 25% polyester and 25% polypropylene. This study is significant as the first microplastic research in the Gelingüllü ecosystem, contributing to limited freshwater studies. Moreover, it holds national and international importance due to its role in fish production and export.