Mercury distribution in two commercial fish species (Pimelodus maculatus and Calophysus macropterus)-Case study of river Acre (Acre state, Brazilian Amazon)

Total mercury (Hg) concentrations were assessed during July 2017 in two commercial fish species Pimelodus maculatus and Calophysus macropterus from two locations of Acre river (Acre State, Brazilian Amazon) - Inapari (undeveloped areas) and Assis Brazil (urban areas). The current study aimed to assess: (i) Hg spatial variations; (ii) the assimilation efficiencies in different tissues and (iii) the ecological quality of these ecosystems based on tissue Hg concentrations. Both species showed significantly (p < .05) different Hg concentrations between tissues. Hg concentrations were significantly higher than those previously reported for these Amazon regions. Hg concentrations in Assis Brazil were significantly higher (p < .05) than in Inapari, indicating an anthropogenic influence. Bioaccumulation factors indicated that kidney and liver are the main Hg retention tissues. Considering European and Brazilian mercury guidelines in foodstuff, Inapari and Assis Brazil are "Unpolluted" during July 2017, although hepatic Hg concentrations in C. macropterus from Assis Brazil showed evidences of anthropogenic contamination.