Uptake of metal in both the laboratory and field showed that the clam P. amurensis was sufficiently responsive to Ag, Cd, Cr, Ni and V to detect environmental differences in exposure. It was less suitable as an indicator of Cu and Zn contamination. Variability within a collection was influenced by gut content and animal size. Temporal and spatial variability was also noted. The grand means of the concentrations of Ag, Cd, Cr, Ni, and V in the tissues of P. amurensis at each station for the 15 mo period revealed persistent contamination from industrialized Suisun Bay to the mouth of San Francisco Bay. -from Authors