Evaluation of the water quality and bioaccumulation of heavy metals in selected fish species of Chaltia Bil, Murshidabad, West Bengal, India

Abstract

Background: Heavy metal contamination in the aquatic ecosystem poses severe ecological and health risks. The present study evaluates the water quality and bioaccumulation of heavy metals in two commercially important fish species (Labeo rohita and Hypophthalmichthys molitrix) from Chaltia Bil, a significant wetland in Murshidabad, West Bengal. Materials and Methods: Water and fish samples were collected from Chaltia Bil in accordance with standard protocols outlined by the APHA (2023) and the FSSAI Lab Manual (2016). The concentrations of heavy metals, including arsenic, lead, cadmium, and mercury, were analyzed using Atomic Absorption Spectroscopy (AAS). Physiological parameters, including temperature, pH, dissolved oxygen, total dissolved solids, biochemical oxygen demand (BOD), chemical oxygen demand (COD), and nutrient levels, were also measured using standard protocols to assess overall water quality. Results: The findings indicate a significant bioaccumulation of heavy metals in fish tissues, with a twelve-fold increase compared to water samples. Lead and arsenic were detected at concerning levels, exceeding WHO and FSSAI permissible limits. Physicochemical analysis revealed variations across sampling points, characterized by high BOD and COD, indicating the presence of organic pollution. Conclusion: The study underscores the urgent need for regular monitoring and mitigation measures to control heavy metal pollution in Chaltia Bil. The bioaccumulation of toxic metals in fish species poses substantial risks to aquatic life and human consumers.