Effects of suction dredging on water quality and zooplankton community structure in a shallow of eutrophic lake,were evaluated.The results showed that a decreasing trend for levels of phosphorus,organic matter,total suspended solids,Chlorophyll a and Secchi transparency in the water column was found,while levels of water depth,electrical conductivity,total dissolved solids and NO 3--N concentration increased markedly post-dredging.The effects of dredging on dissolved oxygen,pH value and temperature were almost negligible.The zooplankton community structure responded rapidly to the environmental changes caused mainly by dredging.As a result,the abundance of rotifers decreased,while the density of zooplanktonic crustaceans increased markedly.The representative taxa were Brachionus angularis,B.budapestinensis,B.diversicornis,Synchaeta spp.and Neodiaptomus schmackeri.A distinct relationship between zooplankton taxa composition and their environment,unraveled by a redundancy analysis,indicating that the measured environment contributed to the variations in the zooplankton community structure to some extent.The first four synthetic environmental variables explained 51.7% of the taxonomic structure.Therefore,with the reduction of internal nutrient load and a shift in dominance by less eutrophic species,it inferred that dredging might be one of effective measures for environmental improvements of such lakes.
