Response of Benthic Fauna and Changing Sediment Redox Profiles over a Hypoxic Gradient
Response of Benthic Fauna and Changing Sediment Redox Profiles over a Hypoxic Gradient
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低氧梯度下底栖动物群的响应和沉积物氧化还原曲线的变化
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
R. Díaz
中科院分区：
文献类型：
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作者：
R. Rosenberg;H. Nilsson;R. Díaz
Koljofjord是瑞典西海岸的一个封闭的分层峡湾，一年中的大部分时间都是低氧/缺氧的底水。在1999/2000年冬季，整个峡湾的水经过一段时间的停滞后重新充氧，但随后的夏季，在20至40米深度之间，氧浓度下降到1 ml l - 1以下。本研究的目的是研究沿氧浓度下降深度梯度的底栖生物群落结构以及动物对沉积物氧化还原条件的影响。沉积物中动物群的垂直分布被限制在上部几厘米。大多数站点的优势种为穴居动物Capitella capitata和造管动物pseudpolydora antennata。在峡湾发现的物种可能对缺氧没有特别的耐受性，但它们的生活史特征有助于在改善氧气条件后快速定居。氧化还原电位不连续层（RPD）的深度是氧化（亚氧）和还原化学条件之间的一个可识别的划分区，它取决于动物活动，例如洞穴、管道和喂养空隙。从沉积物剖面图像（SPIs）测量表观RPD （aRPD）与电极测量RPD相比效果良好。我们得出结论，与电极测量的RPD相比，从图像中进行aRPD的数字分析具有许多优势。
The Koljofjord is an enclosed, stratified fjord on the Swedish west coast with hypoxic/anoxic bottom water during most of the year. In the winter 1999/2000, the water in the entire fjord was re-oxygenated after a period of stagnation, but the following summer oxygen concentrations declined to below 1 ml l−1between 20 and 40 m depths. The objectives of this study were to investigate the structure of benthic communities along a depth gradient of declining oxygen concentrations and the impact of fauna on sediment redox conditions. The vertical distribution of the fauna in the sediment was restricted to the upper few centimetres. Dominant species at most stations were the burrower Capitella capitata and the tube-builder Pseudopolydora antennata. The species found in the fjord are probably not particularly tolerant towards hypoxia, but they have life-history traits that facilitate a rapid colonization following improved oxygen conditions. The depth of the Redox potential discontinuity (RPD) layer, a recognizable division zone between oxidized (sub-oxic) and reduced chemical conditions, is dependent on infaunal activity, e.g. burrows, tubes and feeding voids. Measurement of apparent RPD (aRPD) from sediment profile images (SPIs) compared well to electrode measurement of RPD. We conclude that a digital analysis of aRPD from images has many advantages compared to RPD measurements by electrodes.