Relationship between mercury concentrations in the blood with that in the muscle of four estuarine tropical fish species, Rio de Janeiro State, Brazil.

The aim of this work was to assess the relationship between mercury concentrations in the blood with that in muscle for non-invasive mercury contamination assessment in fish. At Ribeira Bay were collected 198 fishes of 4 species (Genidens genidens, Arius luniscutis, Haemulon steindachneri, Micropogonias furnieri). At Guanabara Bay were collected 84 fishes of 2 species (Genidens genidens, Micropogonias furnieri). Means of mercury concentrations in fish muscles in both areas were below 500 ng/g. The mean ratio, including all specimens of all species, for mercury in muscle-to-whole blood was 13.4:1, for muscle-to-erythrocytes, 6.5:1 and for erythrocytes-to-plasma, 6.5:1. Further studies are necessary to insure that blood could be used as an exposure biomarker, in order to assess mercury availability in aquatic ecosystems.