Assessment of toxicities and threat to biodiversity in an industrial effluent discharged environment

Congenial aquatic habitat environment is inevitable for proper existence of its biodiversity. The present study was conducted with the objectives of assessing pollution intensity and status of aquatic biodiversity which were exposed to industrial effluents contaminated aquatic environment of Mokosh beel in Kaliakair upazila of Gazipur district, Bangladesh. Comparative evaluation of biodiversity before and after discharged of composite effluents to Mokosh beel was accomplished. Analyzing of relevant samples and local respondent’s responses were appraised to achieve the objectives. Decreased dissolved oxygen 0.29 and 0.14 mg/L, increasing chemical oxygen demand 333.33 and 480.0 mg/L, and total solids 2100 and 1800 mg/L of wastewater were recorded in the years 2016 and 2017, respectively implied its severe pollution. Remarkable increase of heavy metals (Cd, Pb, Cr, Ni, Zn, Mn, Fe & Cu) was monitored in wastewater, sediment and plants samples. Among these, Fe was attained in top position, which was reflected in fishes and rice grain. Despite of iron (Fe), Zn and Mn were estimated higher than the permissible values in fishes and rice also. Subsequently the aquatic biodiversity was decreased remarkably. Perhaps these toxic foods and contaminated habitat were treated as enormous threat to its biodiversity. The obtained findings were helpful for the relevant personnel for awareness of public and proper management of aquatic environment.