Physicochemical and microbiological evaluation of surface water quality of aquaculture ponds Located in Savar, Dhaka, Bangladesh

Aquaculture is one of the most vital sectors in Bangladesh as it exhibits a major role in nutrition, livelihoods and foreign exchange earnings every year. Aquaculture in our country is highly impacted and presently triggering serious health risks due to chemical impurities, infectious diseases caused by pathogenic microorganisms and heavy metal accumulation. The industrial sewages and wastes likewise deteriorate severely the water quality and aquatic ecosystems of ponds, rivers, lakes and various waterways located in Savar, Dhaka, as this area is located within one of the major industrial zones in Bangladesh. In the current investigation, water samples were collected from the five selected ponds situated in Atomic Energy Research Establishment (AERE) premises, Savar, Dhaka and water quality assessment was done by analyzing different physicochemical and microbiological parameters according to the standard procedures. The acquired values for pH, temperature, salinity, total alkalinity (TA), total dissolved solids (TDS), electrical conductivity (EC), total hardness (TH), chloride content, free CO2, dissolved oxygen (DO), nitrate ion and sulfate ion were compared with the recommended standard values of Bangladesh and WHO guideline for suitable water quality. Some of the physicochemical parameters showed values lower than the standards for pond water that are inappropriate for aquaculture. Total viable count, total coliform and fecal coliform count were found to be higher than the guideline values of WHO indicating fecal contamination of the water. Various pathogens which can cause fish infections and diseases were also isolated from the ponds. Water quality index (WQI) was calculated for five sampling sites to determine the level of pollution and it was observed that the water quality of all the ponds reached to critical point of pollution. The results revealed that the pond waters of five different sites were excessively polluted and unsuitable for fish culture.