Exploring the use of compound-specific carbon isotopes as a palaeoproductivity proxy off the coast of Adélie Land, East Antarctica

Type Article
Date 2021-10
Language English
Author(s) Ashley Kate E.ORCID1, Crosta Xavier2, Etourneau Johan2, 3, Campagne Philippine2, 4, Gilchrist Harry1, Ibraheem UthmaanORCID1, Greene Sarah E.ORCID1, Schmidt SabineORCID2, Eley YvetteORCID1, Massé Guillaume4, 5, Bendle JamesORCID1
Affiliation(s) 1 : School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
2 : EPOC, UMR-CNRS 5805, Université de Bordeaux, 33615 Pessac, France
3 : EPHE/PSL Research University, 75014 Paris, France
4 : LOCEAN, UMR CNRS/UPCM/IRD/MNHN 7159, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris, France
5 : TAKUVIK, UMI 3376 UL/CNRS, Université Laval, 1045 avenue de la Médecine, Quebec City, Quebec, G1V 0A6, Canada
Source Biogeosciences (1726-4170) (Copernicus GmbH), 2021-10 , Vol. 18 , N. 19 , P. 5555-5571
DOI 10.5194/bg-18-5555-2021
WOS© Times Cited 4
Abstract

The Antarctic coastal zone is an area of high primary productivity, particularly within coastal polynyas, where large phytoplankton blooms and drawdown of CO2 occur. Reconstruction of historical primary productivity changes and the associated driving factors could provide baseline insights on the role of these areas as sinks for atmospheric CO2, especially in the context of projected changes in coastal Antarctic sea ice. Here we investigate the potential for using carbon isotopes (δ13C) of fatty acids in marine sediments as a proxy for primary productivity. We use a highly resolved sediment core from off the coast of Adélie Land spanning the last ∼ 400 years and monitor changes in the concentrations and δ13C of fatty acids along with other proxy data from the same core. We discuss the different possible drivers of their variability and argue that C24 fatty acid δ13C predominantly reflects phytoplankton productivity in open-water environments, while C18 fatty acid δ13C reflects productivity in the marginal ice zone. These new proxies have implications for better understanding carbon cycle dynamics in the Antarctica coastal zone in future palaeoclimate studies.

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How to cite 

Ashley Kate E., Crosta Xavier, Etourneau Johan, Campagne Philippine, Gilchrist Harry, Ibraheem Uthmaan, Greene Sarah E., Schmidt Sabine, Eley Yvette, Massé Guillaume, Bendle James (2021). Exploring the use of compound-specific carbon isotopes as a palaeoproductivity proxy off the coast of Adélie Land, East Antarctica. Biogeosciences, 18(19), 5555-5571. Publisher's official version : https://doi.org/10.5194/bg-18-5555-2021 , Open Access version : https://archimer.ifremer.fr/doc/00729/84134/