ACUTE TOXICITY OF BALLAST WATER ON Clarias gariepinus JUVENILES

Abstract

The indiscriminate discharge of ballast water into the aquatic environment could bioaccumulate in the food chain and pose serious problems for animal and human health. Biological monitoring involving the use of aquatic organisms provides good indication of environmental pollution by toxic materials in wastewaters. In this study, Clarias gariepinus juveniles were exposed to different concentrations of ballast water under laboratory conditions to determine the 96 h LC50 value. The acute toxicity of exposed juveniles was found to be 28.1 ml/L with lower and upper confidence limits of 3.59 ml/L and 20.80 ml/L respectively. Juveniles showed abnormal behaviours including restlessness, erratic swimming, loss of balance, respiratory distress and death. The degrees of the abnormalities were directly proportional to the ballast water concentration.