Santanu Debnatha* & A.K. Panigrahia**
*aFisheries and Aquaculture Extn. Laboratory
a**Dept. of Zoology, University of Kalyani, Kalyani- 741235, W.B, India.
Received: 21st December, 2012 ; Revised: 18th February, 2013
Abstract : The present study deals with the limnological investigations relation to anticipated effects of migratory waterbirds in Purbasthali lake, an ox-bow lake of district Burdwan,West Bengal. The meandering nature of river Ganga in its lower course in West Bengal has given rise a large number of floodplain wetlands, mostly open type ox-bow lakes. These floodplain wetlands are rich in biodiversity (both floral and faunal) and are considered among the most productive ecosystems and play a very important role in socio-economic condition of the neighbouring regions as they are used for commercial fisheries (both culture and capture fisheries). This ox-bow lake is famous here for thousands of migratory bird coming here from far off places including Siberia in winter months. In our study period we examined the relation between different physico-chemical parameters and the waterbird population. The addition of bird guano increased the nutrients like sulphate, phosphate, nitrate etc. in the water and was rapidly utilised by higher gross productivity (GPP) as well as by secondary production of the water body. The limnological parameters in different seasons (viz. Pre monsoon, monsoon and post monsoon) vary greatly in this ox-bow lake. In our study period the mark changes in the limnological parameters of this waterbody during winter months was observed due to the activities of a large number of migratory avifaunal population.