A study on water quality parameters and benthos abundance in freshwater homestead ponds of Dinajpur, Bangladesh

Abstract

An experiment on water quality parameters and the abundance of benthos in freshwater homestead ponds was carried out for a period of 90 days from Dinajpur district of Bangladesh. The study was conducted considering three treatment ponds such as T1 (small sized), T2 (medium sized) and T3 (large sized) and each has three replications. Different water quality parameters were measured at 15 days interval. The ranges of water temperature were 24 to 34 °C, transparency 27 to 36 cm, dissolved oxygen 3.75 to 4.97 mgl-1, pH 6.16 to 7.10, total alkalinity 28 to 122 mgl-1, chlorophyll-a 4.76 to 460.77 µgl-1, ammonia-nitrogen 0.01 to 0.70 mgl-1, phosphate-phosphorus 0.12 to 0.99 mgl-1, nitrite-nitrogen 0.00 to 0.26 mgl-1 and nitrate-nitrogen 0.01 to 0.45 mgl-1 were found among three treatments. Significantly varied values of transparency, total alkalinity and nitrate-nitrogen were observed while other parameters showed non-significant among three treatments. Four groups of benthos i.e. Oligochaeta, Chironomidae, Mollusca and Unidentified were distinguished during the study period. Oligochaeta was dominant among different groups of benthos. The mean (±SD) values of total benthos were 526.75±76.30, 498.77±68.72 and 553.09±61.53 in T1, T2 and T3 respectively. The highest total benthos abundance was recorded in T3 due to its comparatively better water quality. The research findings will be beneficial for the pond owners for the improvement of homestead fish production.