TP10 Acclimation / Adaptation of Animals to Metals: Resistance, Tolerance, and Cost
Tuesday, 15 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall
(BEA-1116-443017) Effects of Pulsed Copper Exposures on Early Life Stage Pimephales promelas.
Bearr, J1, Diamond, J1, Latimer, H1, Bowersox, M1, 1 Tetra Tech, Inc
ABSTRACT- Effects of pulsed copper exposures were investigated using <24-h Pimephales promelas in short-term chronic testing (7 or 14-d). Concentrations tested were between the species mean chronic value (22 
g/L at hardness of 100 mg/L CaCO3) and the 7-d continuous exposure EC50 (40 g/L) to examine exposures that were not acutely toxic and representative of actual wastewater discharge permit exceedences. The primary experimental variable was recovery time between copper pulses. Survival was the main endpoint affected (ANOVA, p = 0.05). Effects on fish survival occurred at lower concentrations (7 to 50%) than the corresponding continuous exposure EC50. Exposures with recovery times of 48 to 96-h between pulses had less effect on survival than treatments with shorter or longer recovery times. Results suggest that the criteria averaging periods used in the U.S., and the averaging periods typically used in wastewater discharge permit limits for copper may not protect against effects of pulsed exposures.
Key words: Pulse Exposure, Acclimation, Copper, Pimephales promelas