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

Abstract

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 (wet wt.) in P. perna and from 4.51 to 23.19 μg kg (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.

A Pilot Study of Mercury Distribution in the Carapace of Four Species of Sea Turtles from Northeastern Brazil

“…Although our results for this single individual cannot be extrapolated to the species level, similarly low Hg levels have been previously reported in scutes of E. imbricata (Escobedo-Mondragón et al 2021, 2023. E. imbricata forage on a low trophic level, mainly on sponges, but also on other reef-encrusting organisms (Bjorndal 1997) which may or may not contain low Hg concentrations (e.g., Orani et al 2020 for sponges, and Rizzini et al 2016). Therefore, it is necessary to further investigate the diet of the E. imbricata population from the present study to better understand these low Hg levels.…”