Epibenthic macrofauna associated with the shelf and slope of a young and isolated Southern Ocean island
Epibenthic macrofauna associated with the shelf and slope of a young and isolated Southern Ocean island
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DOI：
10.1017/s0954102008001107
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发表时间：
2008-06-01
影响因子：
1.6
通讯作者：
Brandt, Angelika
中科院分区：
文献类型：
--
作者：
Kaiser, Stefanie;Barnes, David K. A.;Brandt, Angelika
偏远的南桑威奇岛弧是一个由小火山岛和海山组成的群岛，完全被深水包围，距离最近的岛屿南格鲁吉亚约600公里。作为一些最年轻的岛屿（<500万年），在南大洋，它们是研究底栖动物在海底定居过程的理想工具，但由于地处偏远和极端天气，很少进行调查。目前的研究试图量化的丰富度和丰度的底栖大型动物群周围的南图勒集团采取五个底栖雪橇样本沿着深度样带，包括三个货架（一个在300米，两个在500米）和两个斜坡站（1 000和1 500米）。我们的目的是调查更高的类群丰富度和社区组成在一个孤立的南极地区，因为最近的火山爆发1964年和1997年之间。我们研究了所有底栖大型动物在门和类水平的模式，并调查了一些模式组的甲壳类动物的趋势，以命令和家庭的水平。我们发现，丰度是最高的最浅的样品，并随着深度下降。货架样品（300和500米）主要由软体动物和软介类，而在较深的站（1000和1500米）线虫是最丰富的taxon. Surprisingly，浅水架主要由动物有限的传播能力，如直接发展的育雏（软介类）或lecithotrophic幼虫（双壳类属Yoldiella，大多数苔藓虫物种）。尽管南图勒的地质青年，最近的火山爆发，其偏远的浅架是丰富的高等类群（门/类），以及我们的模型组的订单和家庭。今后在更高的分类分辨率（物种一级）的工作应大大增加对生命如何到达和建立在这些年轻的和高度不安的海底的理解。
The remote South Sandwich arc is an archipelago of small volcanic islands and seamounts entirely surrounded by deep water and about 600 km away from the closest island, South Georgia. As some of the youngest islands (< 5 m.y.) in the Southern Ocean they are ideal for studying colonization processes of the seabed by benthic fauna, but are rarely investigated because of remoteness and extreme weather. The current study attempted to quantify the richness and abundance of the epibenthic macrofauna around the Southern Thule group by taking five epibenthic sledge samples along a depth transect including three shelf (one at 300 m and two at 500 m) and two slope stations (1000 and 1500 m). Our aim was to investigate higher taxon richness and community composition in an isolated Antarctic locality, since recent volcanic eruptions between 1964 and 1997. We examined patterns across all epibenthic macrofauna at phylum and class levels, and investigated trends in some model groups of crustaceans to order and family level. We found that abundance was highest in the shallowest sample and decreased with depth. Shelf samples (300 and 500 m) were dominated by molluscs and malacostracans while at the deeper stations (1000 and 1500 m) nematodes were the most abundant taxon. Surprisingly, the shallow shelf was dominated by animals with restricted dispersal abilities, such as direct developing brooders (malacostracans) or those with lecithotrophic larvae (bivalves of the genus Yoldiella, most bryozoan species). Despite Southern Thule's geological youth, recent eruptions, and its remoteness the shallow shelf was rich in higher taxa (phyla/classes) as well as orders and families of our model groups. Future work at higher taxonomic resolution (species level) should greatly increase understanding of how life has reached and established on these young and highly disturbed seabeds.