ACCUMULATION AND DISTRIBUTION OF METALS IN THE TISSUES OF TWO CATFISH SPECIES FROM CANANEIA AND SANTOS-SAO VICENTE ESTUARIES

Pb, Cd, Zn, and Cu concentrations and their distribution in liver, gill, and muscle tissues of the catfish Cathorops spixii and Genidens genidens were investigated in order to provide information concerning the bioaccumulation processes in these species. Fish were collected in one estuary subject to slight human influence (Cananeia) and in two regions within the Santos-Sao Vicente estuary, Sao Paulo, Brazil, subject to distinct anthropogenic influences: 1) industrial and 2) domestic. In general, the highest concentrations of Cu, Zn, Cd, and Pb were found in the liver tissue. Muscle showed the lowest values of metal accumulation for all the elements investigated. Regarding the distribution and the metal pollution index (MPI), the levels of the metals analyzed decreased in the following order: liver>gill>muscle. MPI results suggest that gill and liver are important organs to exemplify the bioaccumulation process and are also better able to reflect both recent and chronic exposure to metals.