Effects of pH on copper accumulation and toxicity in the common carp, Cyprinus carpio.

Static, short-term acute toxicity tests were performed over a period of 96h, using different concentrations of copper on common carp (Cyprinus carpio) fingerlings (3.2 +/- 1.1 cm and 0.42 g +/- 0.2 g) at pH 6.5, pH 7.5 and pH 8.5. The effect of copper on carp was significantly high (determined as LC50) at pH 6.5 followed by pH 7.5 and pH 8.5. The lethal toxic effect of copper on common carp was directly proportional to pH. Exposure to sub-lethal doses of 0.25, 0.3, 0.35, 0.45 ppm for 15 days indicated that metal concentration and exposure time are determining factors in the copper accumulation processes. Nonetheless the BAF (Bioaccumulation factor) was found to be inversely proportional to cumulative dosage and duration.