Effects of altering freshwater chemistry on physiological responses of rainbow trout to silver exposure. Environmental Toxicology and Chemistry

number of metals [24–27] has enabled the gill to be considered as another ligand in computer-based geochemical models. As-suming that acute metal toxicity will depend on the metal–gill surface interaction [13], prediction of toxicity based on water geochemistry and gill metal burden may be possible. At pres-ent, only copper toxicity to rainbow trout and brook trout has been directly correlated to gill metal accumulation [27]. Con-sequently, more data are required concerning the relationship between metal toxicity and metal speciation and gill metal accumulation. The present study provides information con-cerning the influence of water chemistry on silver toxicity in rainbow trout. Physiological (Na1 influx from the water) and biochemical (gill Na1/K1-ATPase activity) parameters are good indicators of the sublethal effects of metals [28], and were measured to evaluate the effects of silver speciation (by changing water Cl2, Ca21, Na1, and DOC levels within the freshwater range) on silver toxicity in rainbow trout. The re-lationship between these indicators and gill silver accumula-tion was also assessed