Mercury concentrations in invertebrates from Mid-Atlantic Ridge hydrothermal vent fields

Abstract

Mercury determinations were carried out in mussels (Bathymodiolus azoricus) from three Mid-Atlantic Ridge hydrothermal vents (Lucky Strike, Menez Gwen and Rainbow) and shrimps (Rimicaris exoculata and Mirocaris fortunata) from Rainbow. Among the three hydrothermal vents, mussels of Menez Gwen show the highest levels of total Hg and comparing mussels and shrimps from Rainbow the former show more Hg than shrimps. Mussels from different hydrothermal vents are exposed to different kinds of environment which may result in distinct bioaccumulation processes. Detoxification processes in shrimps are related to the low concentrations found. When compared with coastal species from unpolluted sites, mussels show higher concentrations of total Hg and shrimps lower levels. The methyl-mercury concentrations found were very low, not exceeding the detection limit of the technique.