Acute Toxicity of Paper and Pulp Mill Effluents to some Common Indian Freshwater Fauna

Acute toxicity of paper and pulp mill effluentsto Cyclops viridis, Clariasbatrachus and Branchiurasowerbyi was evaluated in the present study. The 96 h LC 50 values of paper and pulp mill effluents for C. viridis, juvenile and adult C. batrachus and B. sowerbyi were 0.62, 2.95, 7.22 and 26.21 mg/liter respectively. C. viridis was most sensitive followed by juvenile and adult C. batrachus and B. sowerbyi . The ethological changes of the organisms were directly proportional to the increasing concentration of paper and pulp mill effluents. The mortality rate also varied significantly with the increasing concentration of paper and pulp mill effluents for both the organisms. The relationship between mortality rate and exposure times was insignificant in all test animals.