A cupric ion-copper bioaccumulation relationship in coho salmon exposed to copper-containing treated sewage

Exposure of coho salmon for 25 days to dilutions of sewage treatment plant effluent with river water containing added Cu (either 35 or 70 micrograms total Cu 1(-1) and an array of Cu2+ concentrations resulted in accumulations of Cu in gill and liver tissues that (a) correlated positively with the Cu2+ contents of the solutions; (b) reached a plateau coincident with onset of mortalities; and (c) correlated positively between these two tissues. Increases in hematocrit percentage and plasma albumin levels occurred in response to 7 micrograms Cu2+ 1(-1), indicating hemoconcentration. Treatment of blood in vitro under similar conditions resulted in association of Cu with the plasma rather than with the erythrocyte fraction.