[en] Biomonitoring of coastal areas using marine organisms is an attractive approach for studying pollution caused by anthropic discharges. Most of the experiments are based on the collection and analysis of native organisms, but this method has the disadvantage of dealing with many natural variations. In this work, the marine bivalve Perna perna, very abundant in the coast of the State of Sao Paulo, Brazil, was transplanted from a mussel farm and used for biomonitoring of four sites, situated in coastal regions close to domestic and/or industrial discharges. Hg, Cd and Pb were determined in the transplanted organisms by AAS and As, Ca, Co, Cr, Fe, Na, Se and Zn were determined by INAA. (author)