Dredging induced changes in zooplankton community and water quality in Dal Lake, Kashmir, India

Abstract

A study was conducted from July 2013 to June 2014 to assess the outcome of dredging activity on the water characteristics and zooplankton community structure in Dal Lake. An assessment was done with respect to alterations in physico-chemical  parameters and zooplankton community changes in predredged and post-dredging periods. The results showed a considerable  reduction in Secchi transparency while water depth, conductivity, total dissolved solids, nitrate and total phosphorous concentrations increased noticeably in post dredging scenario. Variations in the values of dissolved oxygen, pH and temperature as a result of dredging were not statistically significant. The environmental changes as a result of dredging activity affected the structure and distribution of zooplankton community; the abundance of rotifers decreased, while the crustaceans increased. The prominent taxa were Brachionus sp., Keratella cochlearis, Bosmina longirostris, Chydorus sphaericus and Diaptomus sp.

Key words: Dredging, water quality, zooplankton, rotifer, crustacean.