Sedimentation of 13C-rich organic matter from Antarctic sea-ice algae: A potential indicator of past sea-ice extent

Abstract

Research Article| April 01, 1999 Sedimentation of 13C-rich organic matter from Antarctic sea-ice algae: A potential indicator of past sea-ice extent John A E. Gibson; John A E. Gibson 1Antarctic Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia Search for other works by this author on: GSW Google Scholar Tom Trull; Tom Trull 1Antarctic Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia Search for other works by this author on: GSW Google Scholar Peter D. Nichols; Peter D. Nichols 2Commonwealth Scientific and Industrial Research Organisation, Division of Marine Research, Hobart, Tasmania, 7001, Australia Search for other works by this author on: GSW Google Scholar Roger E. Summons; Roger E. Summons 3Australian Geological Survey Organisation, Canberra A.C.T. 2601, Australia Search for other works by this author on: GSW Google Scholar Andrew McMinn Andrew McMinn 4Institute for Antarctic and Southern Ocean Studies, University of Tasmania, Hobart, Tasmania 7001, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information John A E. Gibson 1Antarctic Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia Tom Trull 1Antarctic Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia Peter D. Nichols 2Commonwealth Scientific and Industrial Research Organisation, Division of Marine Research, Hobart, Tasmania, 7001, Australia Roger E. Summons 3Australian Geological Survey Organisation, Canberra A.C.T. 2601, Australia Andrew McMinn 4Institute for Antarctic and Southern Ocean Studies, University of Tasmania, Hobart, Tasmania 7001, Australia Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1999) 27 (4): 331–334. https://doi.org/10.1130/0091-7613(1999)027<0331:SOCROM>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation John A E. Gibson, Tom Trull, Peter D. Nichols, Roger E. Summons, Andrew McMinn; Sedimentation of 13C-rich organic matter from Antarctic sea-ice algae: A potential indicator of past sea-ice extent. Geology 1999;; 27 (4): 331–334. doi: https://doi.org/10.1130/0091-7613(1999)027<0331:SOCROM>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Organic matter collected in sediment traps at a nearshore marine site in Prydz Bay, East Antarctica, displayed a pronounced seasonal variation in carbon isotopes (expressed as δ13COM). Winter values were fairly constant near −20‰ before increasing to above −15‰ in response to inputs from sea-ice algae in early spring. Particulate organic matter obtained directly from sea-ice cores exhibited very high δ13COM values, typically −15‰ but as much as −8‰, much above the values of organic matter suspended in the water column below the sea ice. The sea-ice algae contributed ∼20% of the annual flux of organic matter, and the δ13COM measurements from a sediment core at the site suggest that this value is representative of the recent past. All of these carbon isotopic compositions are considerably above the extremely δ13C-depleted compositions (generally −25‰ to −30‰) that have been found in many other Antarctic and Southern Ocean studies. The elevated δ13COM values derive from considerable depletion of dissolved carbon dioxide and nutrients within the sea ice and to a lesser extent within stratified surface waters induced by melting sea ice. Thus, elevated δ13COM values in Southern Ocean sediment cores may indicate the presence of sea-ice-hosted algae, rather than temperature or surface CO2 pressure (pCO2) variations. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.