Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin.
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin.
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DOI：
10.1098/rsos.160284
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发表时间：
2016-09
影响因子：
3.5
通讯作者：
Mills RA
中科院分区：
文献类型：
--
作者：
Bell JB;Aquilina A;Woulds C;Glover AG;Little CT;Reid WD;Hepburn LE;Newton J;Mills RA
尽管在集中甲烷渗流区域进行了大量研究，但对更为扩散的甲烷渗流过渡沉积物的范围及其对生物群落的影响了解甚少。我们调查了南乔治亚州边缘约250米深处甲烷含量升高的减少沉积物区域，并报告了一系列地球化学和生物分析的数据。这里的地球化学特征与微弱的甲烷渗流相一致，地表下甲烷消耗的作用显然非常重要，阻止了气体排放到底部水域。因此，甲烷衍生碳对微生物和后生动物食物网的贡献非常有限，尽管硫同位素特征表明饮食贡献的范围比碳同位素比值所显示的要大。大型动物组合优势度高，表明沉积物减少，许多类群为其他类似环境所共有，没有渗漏特有动物群，表明过渡性组合。与其他冷渗区相似，这里也有自生碳酸盐样本，但这些碳酸盐不是作为路面或沉积固结物出现的，而是局限于南极Axinulus antarcticus（双壳纲，Thyasiridae）壳上的斑块，这表明微生物与后生动物相互作用。
Despite a number of studies in areas of focused methane seepage, the extent of transitional sediments of more diffuse methane seepage, and their influence upon biological communities is poorly understood. We investigated an area of reducing sediments with elevated levels of methane on the South Georgia margin around 250 m depth and report data from a series of geochemical and biological analyses. Here, the geochemical signatures were consistent with weak methane seepage and the role of sub-surface methane consumption was clearly very important, preventing gas emissions into bottom waters. As a result, the contribution of methane-derived carbon to the microbial and metazoan food webs was very limited, although sulfur isotopic signatures indicated a wider range of dietary contributions than was apparent from carbon isotope ratios. Macrofaunal assemblages had high dominance and were indicative of reducing sediments, with many taxa common to other similar environments and no seep-endemic fauna, indicating transitional assemblages. Also similar to other cold seep areas, there were samples of authigenic carbonate, but rather than occurring as pavements or sedimentary concretions, these carbonates were restricted to patches on the shells of Axinulus antarcticus (Bivalvia, Thyasiridae), which is suggestive of microbe–metazoan interactions.
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影响因子：
2.5
作者：
Connolly, Rod M.;Schlacher, Thomas A.
通讯作者：
Schlacher, Thomas A.
影响因子：
3.7
作者：
Bell, James B.;Woulds, Clare;Glover, Adrian G.
通讯作者：
Glover, Adrian G.
影响因子：
64.8
作者：
Boetius, A;Ravenschlag, K;Pfannkuche, O
通讯作者：
Pfannkuche, O
影响因子：
2
作者：
Dijkman, Nicole A.;Boschker, Henricus T. S.;Kromkamp, Jacco C.
通讯作者：
Kromkamp, Jacco C.
DOI：
10.1111/j.1439-0485.2006.00123.x
发表时间：
2007-03-01
影响因子：
1.1
作者：
Colaco, Ana;Desbruyeres, Daniel;Guezennec, Jean
通讯作者：
Guezennec, Jean