Acute Toxicity and Behavioural Alterations in Mystus Vittatus (Bloch) Exposed to Paper Mill Effluent

Abstract

The pulp and paper industry has been considered to substantial environmental polluter and user of natural resources. Globally it is sixth largest polluter industry, releasing a wide range of solid, liquid, and gaseous wastes into the environment. This study examines the effects of various concentrations and exposure times on the mortality and behavioural responses of freshwater catfish, Mystus vittatus (Bloch), caused by acute poisoning from paper mill effluent.  The LC₅₀ for 24, 48, 72 and 96 hours of paper mill effluent for Mystus vittatus were 14.405, 11.859, 9.682 and 8.223% (v/v), respectively. The outcome also showed that both exposure period and concentrations of effluent affect the mortality rate. Fishes exposed to effluent exhibited altered behaviour, including increased surface activity, faster fin and opercular movements, redness in eye, excessive mucus secretion, and unbalanced swimming or loss of equilibrium. It was shown that these activities were comparatively elevated, indicating signs of stress, as concentration and exposure period increased. Thus, the present study revealed that paper mill effluent is potentially toxic to fish. Because Mystus vittatus is sensitive to paper mill effluent, it is necessary to regularly monitor natural waterbodies to minimize.