Toggle Main Menu Toggle Search

Open Access padlockePrints

Geochemistry, faunal composition and trophic structuring in reducing sediments on the southwest South Georgia margin

Lookup NU author(s): Dr William Reid

Downloads


Licence

This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Abstract

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 250m 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.


Publication metadata

Author(s): Bell JB, Aquilina A, Woulds C, Glover AG, Little CTS, Reid WDK, Hepburn LE, Newton J, Mills RA

Publication type: Article

Publication status: Published

Journal: Royal Society Open Science

Year: 2016

Volume: 3

Print publication date: 28/09/2016

Online publication date: 28/09/2016

Acceptance date: 25/08/2016

Date deposited: 03/10/2016

ISSN (electronic): 2054-5703

Publisher: The Royal Society Publishing

URL: http://dx.doi.org/10.1098/rsos.160284

DOI: 10.1098/rsos.160284


Altmetrics

Altmetrics provided by Altmetric


Actions

Find at Newcastle University icon    Link to this publication


Share