The monthly change of heavy metal levels in the sea water, sediment and some aquatic organisms in Mersin Bay

Monthly and seasonal concentrations of heavy metals (Cd, Pb, As, Zn, Cu, Cr) were investigated in sea water, sediment, blue crab (Callinectes sapidus), kuruma prawn (Penaeus japonicus), striped seabream (Lithognathus mormyrus), red mullet (Mullus barbatus) and common sole (Solea solea) from Mersin Bay. Sampling was carried out by monthly intervals from June 2010 to May 2011 in three stations selected from the offshore of Mersin, Erdemli and Silifke. The concentrations were found to be below the acceptable levels determined by the official authority of Turkey for water, sediment and above given species. However, it was determined that Cr level in sediment samples obtained from Mersin station and Cd level in a few striped seabream samples for all three stations are higher than these values. The highest heavy metal concentrations in the studied samples were determined in the sediments with respect to all other heavy metals except Zn. The lowest concentrations were detected in sea water in all of the metals studied. The highest density was measured in blue crabs for Zn concentration. The seasonal changes of heavy metal levels varied depending on the heavy metals and the species. In addition, interactions between sea water, sediment and species for heavy metals have been investigated in this study. As a result, although it can not be seen that there is no contamination on the study area, it has been shown that it is important that the monitoring of the area for heavy metal pollution, because heavy metal concentrations in some materials and stations are almost acceptable levels.