Community structure of under-ice fauna in relation to winter sea-ice habitat properties from the Weddell Sea
Community structure of under-ice fauna in relation to winter sea-ice habitat properties from the Weddell Sea
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DOI：
10.1007/s00300-016-1948-4
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发表时间：
2017-02-01
期刊：
影响因子：
1.7
通讯作者：
Flores, Hauke
中科院分区：
文献类型：
--
作者：
David, Carmen;Schaafsma, Fokje L.;Flores, Hauke
与气候变化有关的南极海冰生境的改变将对与冰有关的生物与环境的相互作用产生重大影响，从而对生态系统的运作产生影响。这种相互作用的性质知之甚少，特别是在冬春过渡的关键时期。为了研究海冰和底层水柱特性在冬末/早春构造冰下群落中的作用，我们使用了表面和冰下拖网，从2013年8月至10月在北方威德尔海海冰下的上层2米处采集动物和环境特性。就水文地理和海冰覆盖范围而言，调查区域基本上是均匀的。我们假设，这种明显的同质性的物理制度反映在冰下社区的结构。冰下桡足类以长足剑水蚤、栉哲水蚤等占绝对优势。和近端哲水蚤（67%），南极磷虾南极叉尾幼体（30%）。尽管在我们的采样站的环境，丰度和生物量的分布表明存在3个群落类型，在调查区域的地理梯度：（1）高生物量，磷虾为主的西部，（2）高丰度，桡足类为主的东部，（3）低丰度，低生物量的冰缘。结合环境数据分析表明，冰下群落结构与海冰覆盖度、叶绿素a浓度和底深相关。南极冰下群落的异质性可能还受到其他因素的影响，如平流、海冰漂移和季节性变化。因此，冰下群落对海冰生境变化的反应可能因季节和区域而有很大差异。
Climate change-related alterations of Antarctic sea-ice habitats will significantly impact the interaction of ice-associated organisms with the environment, with repercussions on ecosystem functioning. The nature of this interaction is poorly understood, particularly during the critical period of winter-spring transition. To investigate the role of sea-ice and underlying water-column properties in structuring under-ice communities during late winter/early spring, we used a Surface and Under Ice Trawl to sample animals and environmental properties in the upper 2-m layer under the sea ice in the northern Weddell Sea from August to October 2013. The area of investigation was largely homogeneous in terms of hydrography and sea-ice coverage. We hypothesised that this apparent homogeneity in the physical regime was mirrored in the structure of the under-ice community. The under-ice community was numerically dominated by the copepods Stephos longipes, Ctenocalanus spp. and Calanus propinquus (altogether 67 %), and furcilia larvae of Antarctic krill Euphausia superba (30 %). In spite of the apparent homogeneity of the environment, abundance and biomass distributions at our sampling stations indicated the presence of three community types, following a geographical gradient in the investigation area: (1) high biomass, krill-dominated in the west, (2) high abundance, copepod-dominated in the east, and (3) low abundance, low biomass at the ice edge. Combined analysis with environmental data indicated that under-ice community structure was correlated with sea-ice coverage, chlorophyll a concentration, and bottom depth. The heterogeneity of the Antarctic under-ice community was probably also driven by other factors, such as advection, sea-ice drift, and seasonal progression. The response of under-ice communities to changing sea-ice habitats may thus considerably vary seasonally and regionally.