Seasonal variations of water characteristics in three urban ponds with different management practices at Kolkata of West Bengal, India

Abstract

The present study was carried out from January 2014 to June 2014 to make a comparative ecological assessment of three urban ponds of Kolkata, West Bengal, India with different management practices. The average value of water temperature in P-1, P-2 and P-3 ponds were 29.6, 30.0 and 29.8˚C respectively, the average value of water pH was the highest in the P-2 (7.32). The maximum average DO value was found in P-2 (5.66 mg l-1), average value of free CO2 was maximum in the P-3 (38.08 mg l-1). The highest value of alkalinity was found in P-3 (314 mg l-1). The maximum concentration of BOD and COD were recorded in P-3 accordingly (3.07 mg l-1) and (75.16 mg l-1). The highest average value of Phosphate-phosphorous was recorded in P-2 (0.23 mg l-1) and the Nitrate-nitrogen concentration was recorded maximum in P-3 (1.49 mg l-1). The average value of conductivity was highest in P-3(1.97 mS/cm) followed by P-1(1.41 mS/cm) and P-2 (0.77 mS/cm).The present finding established that, the well managed pond (P-2) showed better ecological conditions compare to unmanaged ponds.