Asian Journal of Fisheries and Aquatic Research

The physicochemical and biological attributes of a river ecosystem usually reveal the status of the subsistent aquatic life and affiliated species richness index of the biodiversity. Towards appraisal of water quality, physicochemical parameters (i.e., temperature, pH, DO, transparency and conductivity), water nutrients (nitrate, phosphate) and concentration of chlorophyll a were determined. Samples were collected from seven different stations of Hilsa fishery areas with their special feature. The study revealed a slight spatial variation in physicochemical parameters of river water. While the parameters were found to be at acceptable levels, some measures are needed to improve the quality of water to ensure successful migration and reproduction of the Hilsa fish. The water quality parameter was found slightly alkaline (7.4±0.3). The transparency was found (38.3±11.11 cm) followed by water temperature (22.47±01.79 ºC), alkalinity (101.8 ±19.87), conductivity (2139±2101 µS/cm), CO₂ (6.79±2.43 mg/L), DO (7.56±0.38 mg/L), nitrate (0.006±0.01 g/L), phosphate (0.002±0.0003 mg/L). Chlorophyll a, which represents the biomass of phytoplankton, was estimated (4.58 ± 4.18 mg/L). The largest quantity of plankton as a natural food (both in number and taxa) was found in the Meghna river basin compared to the other rivers. This assessment of the physical, hydrological, chemical and biological profile of the environment of the Hilsa fishery areas of the country delivers obvious evidence which is important to the apprising of the hilsa fisheries management action plan and to the sustainable management of hilsa fishery to a greater extent.