The abundance and speciation of mercury in the Adriatic plankton, bivalves and fish – a review

Abstract

       This article presents an overview of available research on mercury speciation in the most studied biota of the Adriatic Sea as a specific biogeochemical subunit of the Mediterranean. We present current knowledge about mercury concentration, speciation, spatial distribution and temporal changes in plankton, bivalves and fish from the Adriatic Sea. Results from mercury speciation studies in marine organisms are used to describe the extent of mercury bioaccumulation in the Adriatic Sea. Mercury biogeochemical cycle in the Adriatic is characterised by increased mercury concentrations from the water column, through plankton, bivalves and smaller fish to predator fish species. Although the Adriatic Sea has the highest mercury concentration in the whole Mediterranean Sea, fish species at the higher trophic levels have similar mercury concentrations everywhere in the Mediterranean, indicating incomplete understanding of the transfer mechanisms of mercury from seawater to upper trophic levels. As consumption of (contaminated) food is the main route of human exposure to mercury, it is of great importance to understand the influence of mercury contamination in the Adriatic Sea.