Effects of sediment dredging on water quality and zooplankton community structure in a shallow of eutrophic lake

• Published in: Journal of environmental sciences (China) Vol. 22; no. 2; pp. 218 - 224
• Main Authors: Zhang, Shiyang, Zhou, Qiaohong, Xu, Dong, Lin, Jidong, Cheng, Shuiping, Wu, Zhenbin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2010; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Graduate School of Chinese Academy of Sciences, Beijing 100049%State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China%Wuhan Water Authority, Wuhan 430014, China
• Subjects: Animals; Brachionus angularis; Chlorophylls; Communities; Density; Dissolution; Dredging; Environmental Monitoring; Eutrophic lakes; Fresh Water - chemistry; Freshwater; Geologic Sediments - chemistry; internal nutrient load; Neodiaptomus; redundancy analysis; Rotifera; Synchaeta; Water Pollutants, Chemical - chemistry; Water quality; Zooplankton; Zooplankton - physiology; zooplankton community structure; 富营养化程度; 浮游动物; 群落结构; internal nutrient load; zooplankton community structure; redundancy analysis
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/s1001-0742(09)60096-6

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 NO3^--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.