Plankton community structure and variability in the Scotia Sea: austral summer 2003
Plankton community structure and variability in the Scotia Sea: austral summer 2003
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DOI：
10.3354/meps309075
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发表时间：
2006-01-01
影响因子：
2.5
通讯作者：
Cunningham, N
中科院分区：
文献类型：
--
作者：
Ward, P;Shreeve, R;Cunningham, N
浮游生物群落结构在斯科舍海进行了调查，在2003年1月/2月初的基础上，浮游植物细胞计数从20米的深度和中型浮游动物计数从0到400米的净haul。聚类分析和多维尺度显示，4个主要组的站在每个排序，大致对应的地理位置。南极半岛以东的一组站的特点是低浮游植物细胞计数。相应的分组站的中型浮游动物数据的特点是低丰度，越冬状态的许多物种，低产卵率，低碳量的桡足类龄期。相比之下，在斯科舍海的北方的一部分站的分组的特点是叶绿素和浮游动物丰富，夏季代先进。纬度是最强烈的浮游动物群落格局（秩相关p = 0.608），而表面叶绿素a是一个较弱的相关性（p = 0.344），但沿着与尺寸分级叶绿素的措施有助于解释物种阶段的碳质量和产蛋率的变化。额外的拖运到1000米与LHPR表明桡足类种群广泛在该地区南部的越冬状态，而北部的南格鲁吉亚招聘已经完成，一些物种正在经历一个季节性下降。与2000年1月/2月的比较表明，2000年整个斯科舍海磷虾幼虫的丰度较高，桡足类Calanoides acutus的世代也较先进。在2年的冰覆盖有很大的不同，在2000年夏季冰边缘的位置大致符合25年的平均值，而在2003年的冰边缘比平时更远的北部。我们认为，冰撤退的时间影响了繁殖的时间与2003年的后期撤退造成延迟繁殖和减少人口规模。
Plankton community structure in the Scotia Sea was investigated during January/early February 2003 based on phytoplankton cell counts from 20 m depth and mesozooplankton counts from 0 to 400 m net hauls. Cluster analysis and multi-dimensional scaling revealed 4 major groups of stations within each ordination that broadly corresponded geographically. A grouping of stations to the east of the Antarctic Peninsula was characterised by low phytoplankton cell counts. The corresponding grouping of stations in the mesozooplankton data were characterised by low abundance, overwintered state of many species, low egg production rates, and low carbon mass of copepod instars. In contrast, groupings of stations in the northern part of the Scotia Sea were characterised as chlorophyll and mesozooplankton rich, and the summer generation was well advanced. Latitude was most strongly correlated with mesozooplankton community pattern (rank correlation p = 0.608), whereas surface chlorophyll a was a weaker correlate (p = 0.344) but along with measures of size-fractioned chlorophyll contributed towards explaining variation in species stages carbon mass and egg production rates. Additional hauls to 1000 m with an LHPR indicated copepod populations were broadly in an overwintered state in the south of the region, whereas to the north of South Georgia recruitment had been completed and some species were undergoing a seasonal descent. A comparison with January/February 2000 revealed higher abundances of krill larvae throughout the Scotia Sea in 2000 as well as a more advanced generation of the copepod Calanoides acutus. Ice cover during the 2 years differed considerably; in 2000 the position of the summer ice edge broadly accorded with the 25 yr average, whereas in 2003 the ice edge lay much further north than usual. We suggest that the timing of ice retreat influenced the timing of reproduction with the late retreat in 2003 causing delayed reproduction and reduced population sizes.