USO DO BAGRE AMARELO (Cathorops spixii) COMO MODELO BIOLÓGICO DE EXPOSIÇÃO E EFEITO DE CONTAMINANTES NO COMPLEXO ESTUARINO

Many marine and estuarine protected areas present moderate levels of contamination therefore biological responses are not so evident. Thus, environmental risk assessments should not be restricted to chemical sediment analysis, but it is also necessary to evaluate biological parameters that are able to early indicate the potential effects of xenobiotics, such as biomarkers. The first aim of current work was to investigate the role of a set of biomarkers (GPx, GST, GSH, DNA damage, LPO, AChE and condition index) in different target organs (liver, kidney and gills) of a demersal fish (Cathorops spixii) and its relationship with contaminants (metal body burdens on liver and muscle tissues and PAHs in bile), in order to assess the environmental quality of the Marine Protected Area of Cananéia-Iguape-Peruíbe (APA-CIP), affected by former mining activities and urban settlements. The second goal was to use different structural and molecular tools to detect possible genotoxic effects in C. spixii from the APA-CIP. The third aim was to assess correspondences, complementarity, or conflicts among multiple sediment quality LOEs, including biomarkers analyzes, through a WOE sediment-quality assessment. The fourth aim was to estimate the potential risk of the consumption of C. spixii from APA-CIP for human health. The results confirmed the usefulness of the biomarker approach for the identification of both seasonal and spatial variations in pollution sources around APA-CIP. The liver was found to be more responsive in terms of its antioxidant responses, whereas gills were found to be more responsive to biomarkers of effect. APA-CIP seems to be influenced by two sources of contamination: Ribeira de Iguape River (RIR) mouth and urban areas of Cananéia city. The results of different genotoxicity responses showed that micronucleus and nuclear alterations were more frequently associated with the metal body burdens than the analyses of DNA damage, which suggests that the first analyses are less vulnerable to the effects of confounding factors in mildly contaminated areas. The used of biomarker indices within a WOE approach showed that the biomarker index that incorporates histopathological lesions in resident fish was better associated with sediment toxicity and contamination, whereas the biomarker indices that included only sub-cellular and cellular responses were better associated with metals and As body burdens. Metals and As burdens in muscle or liver tissue, in turn, did not associate with sediment levels of these contaminants, suggesting that C. spixii have a mechanism of internal metal regulation. Cd, Pb, and As were found at concentrations above action levels for human consumption. The study of the risk of C. spixii consumption showed that, depending on the level of exposure of the local population, the levels of metals and As in C. spixii pose risk to human health. Taken altogether, the results of this study showed that more attention should be directed to the protection of MPA in order to minimize risks to the resident biota and sensitive human population.