Regulatory Implications of Chemosensory and Behavioral Effects of Anthropogenic Chemicals to Fish

Regulatory criteria for the protection of aquatic life from exposure to anthropogenic chemicals are based primarily on laboratory toxicity data using test endpoints derived on the basis of survival, growth, and reproduction. These endpoints are generally believed to provide the best representation of overall ecological impacts of chemicals to populations of aquatic organisms in the field. However, some have proposed that aquatic life criteria for copper are insufficiently protective of sublethal chemosensory and behavioral endpoints in salmonid fishes, and therefore regulatory criteria need to be revisited. This talk will review the ecological basis of aquatic life criteria derivation using the more traditional endpoints of survival, growth, and reproduction, and discuss the extent to which other sublethal endpoints may influence how criteria are derived. For copper, we contend that traditionally based aquatic life criteria are adequately protective against chemosensory or behavioral effects in salmonid fishes. In large part this is because other aquatic species (e.g., cladocerans) are more sensitive to copper than are salmonid fishes, but also owing to the influence of water chemistry (i.e., pH, hardness, salinity, and dissolved organic carbon) on the toxicity of copper regardless of whether traditional or non-traditional sublethal endpoints are considered.