南澳岛北部海域浮游动物生态学特征及水团影响

Ecological characteristics of zooplankton and impact of water masses in the northern waters of Nan'ao Islands

根据2011年-2012年南澳岛北部海域4个季节的调查资料,对该海域浮游动物的种类组成、生态类群、栖息密度、生物量和多样性指数等生态学特征进行了分析,并探讨了水团变化对浮游动物分布的影响。研究海域内共鉴定出浮游动物150种。浮游动物生态类群以暖水沿岸种、暖水外海种和暖水广盐种3个类群为主,群落组成具有明显的季节变化。浮游动物密度年均值为144.67个·m^-3,季节变化呈双峰型,生物量年均值为98.67 mg·m^-3,季节变化呈单峰型。海区内浮游动物优势种以近岸种为主,其中,瘦尾胸刺水蚤（Centropages tenuiremis）是唯一全年优势种。生物多样性指数以夏季最高,冬季最低。浮游动物生态特征呈现典型的亚热带海湾生态学特性,其变化规律与该海区外海暖水、闽浙沿岸流以及径流冲淡水等水团的季节性消长相关,尤其是近岸径流。

According to the four seasonal cruises on the zooplankton in the northern waters of Nan＇ ao Islands in April,August,November 2011 and February 2012,the species compositions,ecological groups,abundance,biomass,dominant species and diversity index of the zooplankton were investigated and the correction between water masses and zooplankton was evaluated. A total of 158 zooplankton species were identified,including 46 species in spring,104 species in summer,96 species in autumn and 44 species in winter. The zooplankton community structure varied with the seasons,including three main ecological groups,such as warm water neritic species,warm water oceanic species and warm water euryhaline species. The abundance of the zooplankton was 292. 31 ind·m^- 3in summer,143. 25 ind·m^- 3in winter,116. 65 ind·m^- 3in autumn and 26. 48 ind·m^- 3in spring. The zooplankton biomass was140. 15 mg·m^- 3in summer,126. 75 mg·m^- 3in autumn,89. 84 mg·m^- 3in winter and 37. 96 mg·m^- 3in spring. Most of the dominant species were neritic species and Centropages tenuiremis was only one of the annual dominant species. The species diversity of zooplankton was the highest in summer and the lowest in winter. The zooplanktonic ecological characteristics which were closely relatedwith the seasonal variation of water masses,especially the runoffs,had the typical subtropical estuary ecological characteristics in the zone.