A Review of Copper Effects on Fish Behavior

Concerns have been raised regarding the potential adverse effects of copper on fish behavior at concentrations lower than U.S. Environmental Protection Agency (EPA) water quality criteria. To evaluate these concerns, EPA performed a literature review of copper effects on the behavior of both freshwater and marine fish. Information on the behavior of 58 freshwater and 16 marine fish species was found, with a combined total of 180 LOEC’s and 53 NOEC’s. Laboratory studies with copper alone, as part of mixtures, and field behavioral studies were all reviewed. Of the over 120 LOEC values for laboratory studies with copper in freshwater, 97% were higher than the EPA hardness adjusted chronic copper criterion. All 20 laboratory LOEC’s for marine fish exposed to copper alone were higher than the marine chronic criterion. Avoidance behavior is the most commonly studied endpoint, and is the only endpoint with LOEC’s lower than the freshwater chronic copper criterion.  Other behavioral endpoints with available copper effects data include voluntary and involuntary movements, swimming, feeding, social, reproductive and respiratory behaviors.  At least for copper, behavioral responses generally do not occur at concentrations lower than those associated with reproductive and growth effects, meaning the existing hardness dependent copper criterion is acceptably protective from adverse behavioral effects.