提要根据2007—2011年每年春季在珠江口中东部水域6个站位的调查数据，对该水域的水母种类组成及其数量变化进行了研究。结果表明：调查水域春季水母种类组成上以软水母为主，总种类数在2007--2009年略有下降（平均为13种），2010年下降明显，仅为7种，而2011年大幅增至18种。软水母和栉水母在水母总丰度中占有较大比例，2007--2010年水母平均丰度为91．77ind／m3，2011年水母数量急剧上升，高达1185．07ind／m。，其中河口半成淡水种弗洲指突水（Blackfordia virginica）和近岸暖水种球型侧腕水母（Pleurobrachia globosa）增加尤为明显；浮游动物总丰度中水母所占比例从2007年的0．5％上升至2011年的51．1％。地理分布上，水母密集区主要位于调查区域的中北部：环境因素如表层叶绿素a、桡足类丰度、地形和潮汐等对水母的集群现象有影响。%Based on the data of ecological survey in the mid--eastern Pearl River estuary during the springs of 2007--2011, the results showed that： The dominant species of medusa were belonged to Leptomedusa, the species number of medusa slightly declined during 2007--2009, but decreased significantly in 2010, and sharply increased to 18 species in 2011. The average abundance of medusa was 91.77ind/m3 during the springs of 2007--2010, while it dramatically in- creased to 1185.07ind/m3 in 2011, which is dominated with estuarine species Blackfordia virginica and warm water species Pleurobrachia globosa. The relative abundance of medusa was increased from 0.5% in 2007 to 51.1% in 2011. Medusa mainly aggregated in the upper part of the survey area. The environmental factors that influenced the aggregation of me- dusa were surface chlorophyll a, copepod abundance, topography and tidal.
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