Cu is an essential micronutrient and acts as a co-factor in
multiple enzymatic processes but is potentially toxic to aquatic
organisms. While Cu is present in all aquatic environments,
multiple anthropogenic activities may result in elevated con-
centrations, increased exposure, and potential toxicity to aquatic
organisms.However, the concentration ofCu in the aquatic envi-
ronment is not the sole factor dictating the likelihood of adverse
effects. A wealth of studies has demonstrated unequivocally that
complexation of Cu with organic and inorganic ligands as well
as competition with other cations for binding and uptake path-
ways greatly influence Cu toxicity in FW (McGeer et al., 2002;
Paquin et al., 2002; Santore et al., 2001).