Microplastic Abundance in the Mouths of Rivers and Streams Reaching the Marmara Sea and the Bosphorus

 Abstract — In this study, the distribution, type, size and color of microplastics (MPs) in 9 stream mouths pouring into the Marmara Sea were investigated. Both sea surface water and deep sea sediment samples were collected to determine MP abundance at these stream (STR) stations. According to the results obtained, the spatial distribution of microplastics was determined. Higher MP abundance has been detected at the mouths of rivers where anthropogenic and industrial activities are intense. While the highest MP content was found in STR-3 (Ayamama Stream) in sea surface samples, STR-6 (Kağıthane Stream) was the station where the highest MPs were observed in deep sediment samples. On the other hand, while fragments were dominant type MPs in sea surface samples, filament type MPs were dominant in deep sea microplastics