Effects of poultry litter on the chronic toxicity of cadmium to common carp (Cyprinus carpio)

Static 90 day bioassays were made in outdoor cement tanks (300 l capacity) with fries of common carp (Cyprinus carpio) exposed to 1.0, 2.5 and 5.0 mg/l of cadmium (Cd) treated individually and with 250 mg/l poultry litter. Addition of poultry litter significantly reduced the concentrations of dissolved Cd in water and whole body Cd in fish and plankton. In contrast, concentrations of total Cd in sediment increased under the influence of poultry litter. Cadmium showed a distinct partitioning pattern in the sediment. Addition of poultry litter did not change the partitioning pattern. Growth of fish, in respect to length and weight, was reduced by all levels of Cd exposure. In contrast, maximum weight gains, increased lengths, increased specific growth rates and yields were recorded under the influence of poultry litter alone. Addition of poultry litter reduced the ill effects on growth of fish produced by Cd and proved to be a promising tool to counter Cd pollution in aquaculture.