Depth-related changes to density, diversity and structure of benthic megafaunal assemblages in the Fimbul ice shelf region, Weddell Sea, Antarctica
Depth-related changes to density, diversity and structure of benthic megafaunal assemblages in the Fimbul ice shelf region, Weddell Sea, Antarctica
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DOI：
10.1007/s00300-007-0319-6
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发表时间：
2007-11-01
期刊：
影响因子：
1.7
通讯作者：
Tyler, Paul A.
中科院分区：
文献类型：
--
作者：
Jones, Daniel O. B.;Bett, Brian J.;Tyler, Paul A.
使用拖曳式照相机平台照片，在七个地点调查了位于芬布尔冰架边缘的东北威德尔海陆架的底栖巨型动物的深度相关模式。巨型动物密度随深度而减少，从245米处的77，939公顷（-1）减少到510米处的8，895公顷（-1）。虽然多样性是可变的，H '在1.34和2.28之间，但没有深度相关的模式。多变量分析揭示了两个不同的组合，一个浅的组合与密集的补丁悬浮馈线在未受干扰的地区和深组合，这些都不存在。来自冰山的干扰解释了许多观察到的动物群分布模式。在浅水沃茨可能的影响，观察到的变化，在演替阶段;在较深的沃茨的变化，由于过去的干扰解释动物群的分布。在更深的区域，冰犁形成了一个由细颗粒和粗颗粒沉积物组成的马赛克景观。大型动物总密度在粗沉积物区最高（比细沉积物区高2.9），但多样性在中间区最高（H ' = 2.35）。
The depth-related patterns in the benthic megafauna of the NE Weddell Sea shelf at the edge of the Fimbul Ice Shelf were investigated at seven sites using towed camera platform photographs. Megafaunal density decreased with depth from 77,939 ha(-1) at 245 m to 8,895 ha(-1) at 510 m. While diversity was variable, with H ' ranging between 1.34 and 2.28, there were no depth related patterns. Multivariate analyses revealed two distinct assemblages; a shallow assemblage with dense patches of suspension feeders in undisturbed areas and a deep assemblage where these were not present. Disturbance from icebergs explained many observed patterns in faunal distribution. In shallow waters probable effects of disturbance were observed as changes in successional stages; in deeper waters changes in habitat as a result of past disturbance explained faunal distributions. In deeper areas ice ploughing created a mosaic landscape of fine and coarse sediments. Total megafaunal density was highest in areas of coarse sediment (up to 2.9 higher than in finer sediment areas) but diversity was highest in intermediate areas (H ' = 2.35).