Abundance and distribution of microplastics in sediments of the Eastern Aegean Sea (Izmir Bay, Türkiye)

Microplastics (MPs) have accumulated extensively in the marine environment due to the increasing use of plastic materials and their inadequate disposal. Several investigations have been focused on the presence of MPs in the marine environment but a few of them investigate the presence of MPs in the sediment profiles and distribution dynamics. The aim of the study was to investigate the abundance of MPs in the seabed sediments in the I(center dot)zmir Bay of the Aegean Sea, T & uuml;rkiye and to determine the distribution dynamics of MPs and the factors governing them. The abundance of MPs was 2979 +/- 1560 pieces/kg dry sediment. The dominant MP shape was fragment (59.54 %), followed by fiber (36.77 %), film (3.55 %), the remaining types were found to be less than 1 %. The majority of MPs are smaller than 1 mm. In the distribution of MPs by color, the dominant color was transparent (52 %) followed by blue with 11.07 % and other colors account for less than 10 %. It was determined from FT-IR and Raman analyses that the sediments of the Inner Gulf chemically contain 7 different MPs and polyethylene (PE) and polypropylene (PP), constituting the majority of identified particles. The distribution of MPs in the sediment may be explained by Fe, Mn, Calcite (CaCO3), Biogenic Silica (BSi) and hydrodynamic features in the water column (cyclonic, anticyclonic eddies in the water column, diatom substrate selection, littering and sinking with density increase).