Microplastic contamination in surface waters of the Küçükçekmece Lagoon, Marmara Sea (Turkey): Sources and areal distribution.

The distribution of freshwater and marine microplastics (MPs) varies due to the difference in fresh and seawater densities and MP sources. This study aims to investigate the abundance of MPs and their possible sources in surface waters of different ecosystems, such as sea, lagoon, and lake. We classified MPs in terms of their color and type and established the relationship between the MPs in surface waters with different characteristics. The mean MP abundance (33 particles L) detected herein was higher than that in the previously conducted studies. Fragment particles (37.95%) were determined to be the dominant MP type, and the predominant MP color was blue (75.28%). As for the seasonal MP distribution, its highest content (48.03 particles L) was observed in autumn, unlike that reported by other studies. The findings of this study reveal the effects of wastewater treatment plant (WWTP) discharge and current flow on the MP distribution in the study area. This study aims to provide representative data on the MP abundance and distribution, as well as MP-affecting parameters for similar aquatic areas in other parts of the world.