Mercury speciation in fish of the Cabo Frio upwelling region, SE-Brazil

Abstract

Mercury distribution in the oceans is controlled by complex biogeochemical cycles, resulting in retention of trace amounts of this metal in marine biota. The impact of upwelling processes in this metal behavior has been overlooked. Data from literature are insufficient to evaluate the risks associated with the presence of mercury in the fish collected in upwelling areas and its consumers. Therefore, the aim of the present work was to perform a study of mercury speciation in four fish species belonging to different trophic levels from Cabo Frio-Brazil upwelling region. The total mercury content vary of 53 ng g-1 (Sardinella brasiliensis -sardine) to 1215 ng g-1 (Cynoscion striatus -striped weakfish) and, with exception of the planktivorous fish, methylmercury levels reaches circa 90% of total mercury concentration.