Investigation of Anthropogenic Heavy Metal Pollution in Core Sediments from the Eckernforder and Geltinger Bays in the Western Baltic Sea, Germany

The main purpose of this study was to investigate the effects of increasing human activities (agriculture, urbanization, settlement, wars, industrialization) and cold climatic periods that occurred pre-and post-1800 in and around the western Baltic Sea. To investigate this, sediment box cores were collected onboard the R/V SENCKENBERG in 1978 from two bights of Eckernforder (EB) and Geltinger (GB). Vibration hammer technology was used to obtain undisturbed core sediments and grain size, carbonate, organic carbon, element, SEM-EDAX and Pb-210 dating analysis were carried out. The results were then interpreted using statistical methods. The greyish to black colored mud ("schlick") sediments deposited under suboxic to anoxic. conditions in the bights mainly consists of silicate-aluminosilicate minerals. Carbonate contents in both cores are low (generally <3%) but EB sediments are finer grained than the GB sediments. Regional characteristic source and depositional conditions caused the accumulation of high organic matter (2-6%) in core sediments from both bights. Major element concentrations (Si, Al, K, Mg, Fe, P) largely do not display any significant changes throughout the cores and indicate lithogenic-geogenic sources. The downcore changes in Mn, Co and in part, P, concentrations can be related to sediment diagenesis in the cores. Cr, Ni, Cu, Pb, Zn, Cd and Hg contents showed increases towards the upper core sections. The contamination factors obtained from division of metal concentrations in the upper sections to those from the lowest sections of the cores were 18-76 for Hg (very high contamination), 3.5-4.7 for Cd (considerable, high contamination), 2.1-2.9 for Zn and Pb (low to moderate pollution), and 0.7-1.7 for Cu, Cr, Ni, Co, Mn and Fe (very low to no contamination). In particular, high contamination factors (CF>2) showed the effects of anthropogenic activities present in the region since the 1800s. The presence of coal, ash and metallic slag particles in the sand fractions of the upper 4-22 cm core sections also confirmed anthropogenic effects in the two bights.