Effects of sediment dredging on water quality and zooplankton community structure in a shallow of eutrophic lake.
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.
Zhang
Shiyang
S
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. zhangshiyang@ihb.ac.cn
Zhou
Qiaohong
Q
Xu
Dong
D
Lin
Jidong
J
Cheng
Shuiping
S
Wu
Zhenbin
Z
D000818:Animals; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015048:Zooplankton / Q000502:physiology*
D014874:Water Pollutants, Chemical