Trace elements pollution in surface sediment of the Sea of Marmara coastal and transition water

The increasing anthropogenic activities in the Sea of Marmara, such as industrialization, maritime traffic, and urbanization, have significantly contributed to the introduction of various contaminants, into its sediments. The aim of this study is to determine the levels of trace elements accumulated in the transitional and coastal waters of the Sea of Marmara and to assess the pollution status of the region. Surface sediments were collected using a Van Veen Grab from 21 stations representing different water masses in May, July, and September 2018 and stored in plastic bags at -21 °C. The concentrations of elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn) were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS, Agilent 7700X). To evaluate sediment quality, Enrichment Factor (EF), Geo-accumulation Index (I_geo), Pollution Load Index (PLI), Contamination Factor (Cf), Contamination Degree (CD), and Factor Analysis were applied. The analysis revealed that Al and Fe were the most abundant elements in the sediments, while Hg and Cd were found at the lowest concentrations. These findings may be associated with the natural geochemical characteristics of the region as well as anthropogenic pollution sources. The index results indicated significant enrichment of certain elements in specific areas. This study provides important data on the accumulation of trace elements in the sediments of the Sea of Marmara. The applied pollution indices offered a comprehensive assessment of sediment contamination in the region, highlighting the localized accumulation of certain pollutant elements.