Zooplankton Community Structure And Environmental Characteristics In Guangzhou-zhuhai Waters Of The Pearl River Estuary

Zooplankton is the important organism group in aquatic ecosystem, which plays a key role inmaterial circulation, information transfer and energy flowing. A survey on zooplanktoncommunity structure and environmental factors was made at Zhongda dock （S1）and Yuzhudock （S2）sampling sites in Guangzhou city segment of Pearl River (from January2007toDecember2013), and at Nansha river （S3）, Humen bridge （S4）and Xiangzhou （S5）sampling sites in the Nansha-Zhuhai segment of Pearl River estuary (from January to Decemberin2013). The main results are included as following:1. Sixty-nine zooplankton species were recorded at the five stations including thirteencopepods, seven cladoceras and forty-nine rotifers. In Guangzhou city segment of Pearl River,nine copepods, five cladoceras, forty-eight rotifers species were recorded, and inGuangzhou-Zhuhai segment of Pearl River estuary, nine Copepods, four Cladoceras, thirty-threeRotifers were identified. The diversity index (H) and evenness index (J) in Guangzhou citysegment were higher than that in Nansha—zhuhai segment. In the Guangzhou city segment ofthe Pearl River Estuary, zooplankton dominant species were Mesocyclops thermocyclopoides,Thermocyclops taihokuensis, Moina micrura, Anuraeopsis fissa, Brachionus angularis, B.calyciflorus, and in the Guangzhou-Zhuhai segment, the dominant species were Pavocalanuscrassirostris, Acatiella sinensis, Bosmina sp., M. micrura, Polyarthra vulgaris, B. angularis.2. During the investigation, zooplankton abundance at Zhongda dock and Yuzhu dock wereranged from2to4165ind. L-1, and13to3676ind.L-1, and mean abundance were1026±1082ind.L-1,1261±801ind.L-1, respectively. Zooplankton abundance were ranged from17to154ind.L-1,5to117ind. L-1,1to82ind. L-1, and mean abundance were59±44ind.L-1,28±32ind.L-1and23±28ind.L-1, at Nansha river, Humen bridge and Xiangzhou whalf sampling sites,respectively.3. Statistical analysis showed that zooplankton abundances at five sites were affectedmarkedly by water temperature, chlorophyll a and salinity. There was a significantly positivecorrelation between chlorophyll a concentrations (X) and zooplankton abundances (Y)(P=0.0001; Y=54.149+0.873X), and a significantly negative correlation between salinity (X) and rotifer abundances (Y)(P=0.001; Y=432.22-179.16lnX).