南极夏季南设得兰岛海域浮游动物群落垂直分布

摘要

Research on the patterns of the vertical distribution of zooplankton could help improve understanding of the role of zooplankton in the marine food web.Based on samples collected in the South Shetland Islands during the 28th Chinese National Antarctic Research Expedition, vertical profiles of the zooplankton community structure were in-vestigated using multivariate analysis and three communities identified.Group 1 contained samples collected in sur-face water (0—200 m).The average abundance of this group was 31 782.02 ind· 1 000 m-3 and the indicator species were mostly copepods: Oithona similis, Ctenocalanus citer, Oncaea curvata, Calanoides acutus, Calanus propinquus,and CalyptopisⅠ—Ⅲstages of Euphausia superba.Group 2 comprised samples from depths of 200—1 000 m.The average abundance was 22 325.59 ind· 1 000 m-3 and the indicator species were mostly O.curva-ta, O.similis, Oithona frigida, C.citer, Aetideopsis minor, Bathycalanus bradyi, C.acutus, C.propinquus, Metridia gerlachei, Alacia spp.and Eukrohnia hamate.Group 3 comprised samples collected in deep water (1 000—2 000 m).The average abundance was only 989.27 ind· 1 000 m-3 and the indicator species was Bathycalanus bradyi.Bio-Env analysis showed that chlorophyll a and salinity were the most significant factors af-fecting community structure and that consideration of these two factors with depth provided the best explanation for the community clustering.%浮游动物群落结构的垂直分布研究可以更好地了解其在海洋食物网物质能量循环中的作用。基于2012年1月中国第28次南极考察期间在西南极南设得兰岛海域4个站位Multinet网（200μm，0．5 m2）采集的浮游动物样品资料，运用多元统计方法对浮游动物群落垂直结构及与环境因子关系进行了分析，结果显示：浮游动物可划分为3个群落，群落1由采自上层水体（0—200 m）的样品组成，此群落平均丰度为31782．02个·1000 m－3，优势种为桡足类Oithona similis， Ctenocalanus citer， Oncaea curvata， Calanoides acutus， Calanus propinquus 及南极大磷虾原蚤状幼体CⅠ-Ⅲ期个体；群落2主要由采自中层水（200—1000 m）的样品构成，群落平均丰度为22325．59个·1000 m－3，其指示物种主要包括桡足类O．curvata， O．similis， Oithona frigida， C．citer， Aetideopsis minor， Bathycalanus bradyi， C． acutus， C．propinquus， Metridia gerlachei，介形类Alacia spp．及箭虫Eukrohnia hamata；群落3由采自较深层水（1000—2000 m）的样品组成，群落平均丰度为989．27个·1000 m－3，其指示种为深水桡足类Bathycalanus bradyi。 Bio-Env分析显示叶绿素a和盐度分别是对群落聚类起关键影响的单因子，水深、盐度和叶绿素a的组合则最好地解释了群落的划分。