Assessing mercury contamination in a tropical coastal system using the mussel Perna perna and the sea anemone Bunodosoma caissarum

Total mercury concentrations in the mussel Perna perna and the sea anemone Bunodosoma caissarum were determined to assess Hg contamination in Guanabara Bay, Rio de Janeiro, Brazil, and an adjacent sea area. Concentrations in the tissues of these species were compared. Average total mercury concentrations ranged from 3.54 to 21.01 μg kg−1 (wet wt.) in P. perna and from 4.51 to 23.19 μg kg−1 (wet wt.) for B. caissarum. Concentrations varied according to the sampling stations. Distribution of concentrations for both species was similar along the sampling stations, and a significant correlation was observed. Results suggest that B. caissarum could be a suitable biomonitor species for mercury contamination in the study area and could be used as a complementary species for monitoring studies. Further research is, however, needed to assess how environmental conditions and other variables affect Hg concentrations in B. caissarum.