Kinetics of Deposition, Acute Toxicity and Bioaccumulation of Copper in some Freshwater Organisms

Experiments with environmentally relevant concentrations of Cu in glass aquaria revealed that Cu was quickly removed from water. Cubic regression of Cu concentration against time showed that maximum rate of removal was around 69.34-72.11 h irrespective of treatment. The 96 h LC₅₀ value of Cu was respectively 0.18, 0.19 and 0.35 mg/L for fish Cyprinus carpio, crustacean Diaptomus forbesi and worm Branchiura sowerbyi. Normalizing the lethal values and plotting them against time it was observed that there was sharp differences in mortality over time between the organisms and 96 h lethal values could misrepresent susceptibility of the organisms to Cu. Treatment of 0.1 mg/L of Cu in water resulted in accumulation of 10.57, 4.38, 1.46 and 2.44 µg/g of Cu, respectively in sediment, worm, crustacean zooplankton and whole body of fish. But, Cu deposited in high concentrations in gut and liver of fish indicating that Cu was principally accumulated through food.