底泥疏浚前后长春南湖浮游生物群落变化研究

Research on variety of plankton community prior and post sediment dredging in Nanhu Lake,Changchun

底泥疏浚是水体内源污染治理的重要手段,通过疏浚期间和疏浚后对长春南湖浮游生物2 a(每年6个月)的跟踪监测,研究了底泥疏浚前后长春南湖浮游生物的种群变化,对比分析了底泥疏浚前后南湖浮游生物的种类组成、数量和生物量变化趋势.结果表明疏浚后浮游植物群落发生了演替,由疏浚前的绿藻-蓝藻-硅藻型演变为目前的绿藻-硅藻-蓝藻型.同疏浚前相比,疏浚后浮游藻类数量平均下降11%,枝角类和桡足类等大型浮游动物所占比例降低;疏浚后浮游动物数量上升,生物量下降,浮游动物存在小型化趋势.

The effects of sediment na. A project of bottom sediment dredging events have been uncommonly dredging has been carried at the Nanhu reported for shallow lake in ChiLake since 2000 in order to control its eutrophication. During the period from May to October monthly in 2002-2003, the characteristic of the water the plankton, zoobenthos had been investigated from 4 sample sites. The objective of this paper was to determine the effects of hydraulic sediment dredging at the Nanhu Lake prior to and after dredging. After dredging, the species number of phytoplankton was 285 and 334 respectively, between 2002 and 2003. The dominated species was stable in 2002-2003. The phytoplankton community took succession from chlorophyta - cyanophyta - diatom of prior to dredging to chlorophyta - diatom - cyanophyta of post dredging. The species numbers of zooplankton were 134 and 117 respectively, between 2002 and 2003. The dominated species was stable in 2002-2003. The zooplankton community changed. The zooplankton community was mainly consisted of protozoa and rotifer, and the number of cladocera and copepoda were less than 1 percent. The phenomena, which the number of zooplankton was up and the biomass was down, demonstrated miniaturization trend of the zooplankton was obvious.