Comparative Distribution of Microplastics in Different Inland Aquatic Ecosystems

The widespread dispersion of microplastics (MPs) has been recognized as a pervasive and per-sistent environmental contaminant in worldwide freshwater ecosystems and although relative studies skyrocketed, there are still knowledge gaps from areas like southern Europe. This study assesses the microplastic pollution in seven Greek inland aquatic ecosystems which vary in morphology, trophic status, and anthropogenic pressure. Surface and vertical samples were taken with 200 μm plankton nets. MPs were present in all samples with fibers being the dominant form having an abundance range between 0.60 and 159.7 n/m3, while fragments between 0.08 and 9.17 n/m3. Fibers and fragments had greater abundance in the vertical than in the surface samples. There were no significant abundance differences between lakes and lagoons, and among the sampling sites in each ecosystem. Blue and transparent were the colors that prevailed while most of the fibers and fragments were smaller than 1 mm. Five types of MPs were recorded with PET being the most frequent among fibers. The use of the novel Relative Anthropogenic Pressure (RAP) index resulted in the highest positive correlations between morphometrical and sociological parameters and the microplastic’s abundance reflecting better the impingement of the human populations on the inland aquatic ecosystems.