Mercury and selenium were assessed in the muscle tissue of cutlassfish (Trichiurus lepturus) from three coastal areas (Ilha Grande Bay, Guanabara Bay and Búzios coast, Rio de Janeiro State, Brazil) that present different environmental conditions, localized in Southeastern Brazil. Hg was determined by cold vapor atomic absorption spectrometry (CV-AAS) and Se was determined by graphite furnace atomic absorption spectrometry (GF-AAS). Across sites, mercury and selenium in this fish ranged from 0.44 to 0.87 µg Hg g-1 and 0.0050 to 3.12 µg Se g-1 dry wt. Significant differences were observed in mercury concentrations and Se:Hg molar ratios among the areas. The total length and size intervals presented a significant influence on the accumulation of mercury, whereas this pattern was not observed for selenium. A large excess of selenium in relation to mercury was observed. Probably, the regional differences can be partly attributed to differences in the prevalent environmental conditions (water temperature and primary production), and also to other factors, such as prey choices and availability across locations.
cutlassfish; trace elements; Se:Hg molar ratio; environmental conditions; South Atlantic Ocean
