Supratim Pal, Debashis Das and Kaushik Chakraborty
Plankton diversity and physico-chemical parameters are important criterion for evaluating the suitability of aquatic health. A comparative study on zooplankton diversity in relation to physico-chemical parameters of two selected wetlands [one natural (NWL) and one man-made (MWL) respectively] was studied at Cooch Behar district of West Bengal. In gross nine physical and chemical parameters and fifteen types of zooplankton species were noted. Study reveals that the physico-chemical characteristics like conductivity (424μS/cm in NWL and 243μS/cm in MWL respectively), total hardness (204mg/lit in NWL and 108mg/lit in MWL respectively), total dissolved solids (211ppm in NWL and 121ppm in MWL respectively), dissolved oxygen (9.63mg/lit in NWL and 8.30mg/lit in MWL respectively) and iron concentration (1.18mg/lit in NWL and 0.79mg/lit in MWL respectively) are higher in natural wetland (Panishala Beel) but pH value (6.8 in NWL and 7.4 in MWL respectively), total suspended solids (5.64NTU in NWL and 24.5NTU in MWL respectively) and chloride concentration (63.9mg/lit in NWL and 70.0mg/lit in MWL respectively) are higher in the man-made wetland (Mali dighi). Study reveals the existence of both high species diversity and numerical abundance of zooplankton population in natural wetland in comparison to man-made wetland. But contrary to this, the density of zooplankton in man-made wetland is comparatively higher in comparison to natural wetland. Observation on the gross physico-chemical parameters on both the aquatic source indicates good water quality. However, lesser zooplankton diversity in man-made wetland is probably due to the short time of species succession following its excavation.
