Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin
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 Geor...
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ftpubmed:oai:pubmedcentral.nih.gov:5043311 2023-05-15T13:45:24+02:00 Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin Bell, James B. Aquilina, Alfred Woulds, Clare Glover, Adrian G. Little, Crispin T. S. Reid, William D. K. Hepburn, Laura E. Newton, Jason Mills, Rachel A. 2016-09-28 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043311/ http://www.ncbi.nlm.nih.gov/pubmed/27703692 https://doi.org/10.1098/rsos.160284 en eng The Royal Society http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043311/ http://www.ncbi.nlm.nih.gov/pubmed/27703692 http://dx.doi.org/10.1098/rsos.160284 © 2016 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. CC-BY Earth Science Text 2016 ftpubmed https://doi.org/10.1098/rsos.160284 2016-10-09T00:13:26Z 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. Text Antarc* antarcticus PubMed Central (PMC) Royal Society Open Science 3 9 160284 |
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English |
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Earth Science |
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Earth Science Bell, James B. Aquilina, Alfred Woulds, Clare Glover, Adrian G. Little, Crispin T. S. Reid, William D. K. Hepburn, Laura E. Newton, Jason Mills, Rachel A. Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
topic_facet |
Earth Science |
description |
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. |
format |
Text |
author |
Bell, James B. Aquilina, Alfred Woulds, Clare Glover, Adrian G. Little, Crispin T. S. Reid, William D. K. Hepburn, Laura E. Newton, Jason Mills, Rachel A. |
author_facet |
Bell, James B. Aquilina, Alfred Woulds, Clare Glover, Adrian G. Little, Crispin T. S. Reid, William D. K. Hepburn, Laura E. Newton, Jason Mills, Rachel A. |
author_sort |
Bell, James B. |
title |
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
title_short |
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
title_full |
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
title_fullStr |
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
title_full_unstemmed |
Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin |
title_sort |
geochemistry, faunal composition and trophic structure in reducing sediments on the southwest south georgia margin |
publisher |
The Royal Society |
publishDate |
2016 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043311/ http://www.ncbi.nlm.nih.gov/pubmed/27703692 https://doi.org/10.1098/rsos.160284 |
genre |
Antarc* antarcticus |
genre_facet |
Antarc* antarcticus |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043311/ http://www.ncbi.nlm.nih.gov/pubmed/27703692 http://dx.doi.org/10.1098/rsos.160284 |
op_rights |
© 2016 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1098/rsos.160284 |
container_title |
Royal Society Open Science |
container_volume |
3 |
container_issue |
9 |
container_start_page |
160284 |
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1766223770250379264 |