Distribution of PCBs in sediment from different bottom types and water depths in Stockholm Archipelago, Baltic Sea

PCBs associate with organic matter in the aquatic environment. Sediment of different bottom types at different water depths may have organic matter wi th different properties. Also the different bottoms can be either oxic/biot urbated or anoxic/laminated, depending on water depth. To investigate if th ese circumstances would influence the distribution of PCBs in sediment, sam ples were collected from different bottom types at different water depths i n two areas in the Stockholm Archipelago in the Baltic Sea. The bottom type s were classified according to their water content. II: was concluded that the concentration of PCBs on an organic carbon basis is the same for the di fferent bottom types and the two areas. The possible differences in propert ies of the organic matter in different sediments is of minor importance, as are the influences of bioturbation and redox conditions. Instead, it is th e properties of the PCB congeners which determine their distribution in the sediments.