Trophic magnification of Hg, PBDE and PCB in population of European perch with varying feeding ecology in the Baltic Sea

Abstract

Marine ecosystems face a significant ecological challenge due to the introduction and cycling of hazardous substances. The recent stabilization of concentrations of specific hazardous substances, which were previously decreasing, indicates significant ongoing processes within the ecosystem. These processes continue to make these substances available within the food chain, even following the implementation of restrictions and the elimination of known anthropogenic sources. The present study investigated the transfer of mercury, PBDEs, PCBs and their congeners via trophic transfer by combining consumer dietary characteristics and concentrations of these pollutants using European perch (Perca fluviatilis) and its prey as model organisms.The elevated concentrations of mercury and the accelerated trophic magnification in the perch population at one of the sampling sites appear to be linked to the selective consumption of Decapoda. However, the frequency of occurrence of any particular prey item in the perch diet does not account for the declining magnification slopes of PCBs at the site. Furthermore, in the distant sampling sites, PCBs and PBDEs do not exhibit consistent trophic magnification slopes. This suggests the significance of pollution loads in the neighboring water bodies and the migration patterns of the assessed species.