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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 incomes/earnings every year. However, due to chemical impurities, infectious diseases caused by microorganisms, heavy metal accumulation, and aquaculture in Bangladesh is gradually declining and posing serious health risks. In Savar, which is one of the major industrial zones in Bangladesh, all industrial sewage and wastes severely deteriorate the water quality of the ponds, rivers, lakes and various waterways that are involved in aquaculture/fish culture. Hence, to determine the water quality by assessing different physicochemical and microbiological parameters, water samples were collected from five selected ponds located in Atomic Energy Research Establishment premises, Savar, Dhaka and analyzed according to the standard procedures. The obtained values of temperature, pH, Salinity, TDS, TA, EC, TH, Chloride content, Free CO2, DO, Nitrate and Sulfate were compared with the recommended values of Bangladesh and WHO standard for suitable water quality. Most of the physicochemical parameters exceeded the Standard value. Total Viable Count, Total Coliform and Fecal Coliform Count were also found to be higher than the standard value of WHO indicating fecal contamination of the pond water. Some fish pathogens were also isolated from the ponds. Water quality index (WQI) was calculated for five sampling sites to determine the level of pollution. It was observed that the water quality of the all the ponds reached to critical point of pollution. It is therefore, a high time to take initiatives to save the ponds that are involved in aquaculture from further pollution. The results revealed that the pond waters of five different sites were excessively polluted and unsuitable for fish culture.