Distribution of macrobenthic taxa across the Scotia Arc, Southern Ocean
Distribution of macrobenthic taxa across the Scotia Arc, Southern Ocean
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DOI：
10.1017/s0954102008001168
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发表时间：
2008-06-01
影响因子：
1.6
通讯作者：
Barnes, David K. A.
中科院分区：
文献类型：
--
作者：
Griffiths, Huw J.;Linse, Katrin;Barnes, David K. A.
一个极具活力的群岛链连接着南美洲和南极半岛。它包括岛屿，有大有小，有老有少，靠近大陆边缘，与世隔绝，样本丰富，鲜为人知。目前的研究使用阿加西拖网在陆架和斜坡深度对该弧形所有主要群岛的大型底栖动物进行了采样。至少在福克兰海槽、沙格岩、南乔治亚州、南图勒、鲍威尔盆地、象岛和利文斯顿岛采集了至少4个样品(200米、500米、1000米和1500米)，并在欺骗岛的火山口采集了1个样品。尽管该区域具有生物地理和生物多样性的重要性，但这是第一次(根据定义)对其所有群岛的整个标准化拖网样本进行分析，并在任何一致的分类水平上进行分析。在所有样本中，我们总共发现了15门29纲的大型和巨型动物，其中许多出现在所有地点。即使是在偏远和地质上年轻的地点，丰富度也很高。丰富度随丰度和湿重的增加而增加，浅海陆架样品的丰富度最高，1500米处最低，丰度和湿重的变化超过两个数量级，甚至在类群或研究区域内也是如此。南图勒和欺骗岛这两个活跃的火山遗址的海鞘主导的浅层动物群之间有很大的相似之处，尽管在隔离方面存在巨大的差异。福克兰海槽和沙格岩之间也有很强的动物群相似之处，尽管它们位于极地阵线的两边。相比之下，基岩相似的两个近邻大象岛和利文斯顿岛是最不同的两个岛屿。
An extremely dynamic chain of archipelagos links South America and the Antarctic Peninsula. It includes islands, which are large and small, old and young, near continental margins and isolated, and well sampled and poorly known. The current study sampled the macrobenthos of all the major archipelagos of this arc at shelf and slope depths using an Agassiz trawl. At least four samples (200 m, 500 m, 1000 m and 1500 m) were taken down-slope at Falkland Trough, Shag Rocks, South Georgia, South Thule, Powell Basin, Elephant Island, and Livingston Island sites and one sample was collected in the caldera of Deception Island. Despite the biogeographical and biodiversity importance of this region, this is the first time (by definition) entire standardized trawl samples have been analysed from all its archipelagos and at any consistent taxonomic level. We found 15 phyla and 29 classes of macro- and megafauna in total across the samples, many of which occurred at all sites. Even at remote and geologically young sites richness was high. Richness increased with abundance and wet mass and was highest in the shallow shelf samples and lowest at 1500 m. Abundance and wet mass varied more than two orders of magnitude, even within classes or study areas. There were strong similarities between the ascidian dominated shallow faunas of the two active volcanic sites, Southern Thule and Deception Island despite huge differences in isolation. There were also strong faunal similarities between Falkland Trough and Shag Rocks despite being on opposing sides of the Polar Front. In contrast two near neighbours with similarly soft substrata, Elephant and Livingston islands were amongst the most dissimilar.