Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century
We reconstructed oxygenation changes in the upwelling ecosystem off Concepcion (36° S), Chile, using inorganic and organic proxies in a sediment core covering the last ca. 110 years of sedimentation in this area. Authigenic enrichments of Mo, U and Cd were observed between ca. 1935 and 1971 CE, impl...
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| Format: | Article |
| Language: | en_US |
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Copernicus GmbH
2016
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| Online Access: | http://hdl.handle.net/1721.1/100568 https://orcid.org/0000-0002-7144-8537 |
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| author | Srain, B. Pantoja, S. Lange, C. B. McKay, J. Salamanca, M. Munoz, P. Sepulveda, Julio C Summons, Roger E |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Srain, B. Pantoja, S. Lange, C. B. McKay, J. Salamanca, M. Munoz, P. Sepulveda, Julio C Summons, Roger E |
| author_sort | Srain, B. |
| collection | MIT |
| description | We reconstructed oxygenation changes in the upwelling ecosystem off Concepcion (36° S), Chile, using inorganic and organic proxies in a sediment core covering the last ca. 110 years of sedimentation in this area. Authigenic enrichments of Mo, U and Cd were observed between ca. 1935 and 1971 CE, implying a prolonged period with predominantly more reduced conditions in bottom waters and surface sediments. Significant positive correlations between redox-sensitive metals, algal sterols, biomarkers of micro-aerophilic and anaerobic microorganisms, and archaeal glycerol dialkyl glycerol tetraethers point to a tight coupling among bottom water O[subscript 2] depletion and increased primary and export production. The time interval with low O[subscript 2] of ca. 35 years seems to follow low-frequency interdecadal variation of the Pacific Decadal Oscillation, and it may have resulted in O[subscript 2] depletion over the entire continental shelf off Concepción. Taking this together with the concurrent increase in sedimentary molecular indicators of micro-aerophilic and anaerobic microbes, we can suggest that changes in oxygenation of the water column are reflected by changes in microbial community. This study can inform our understanding of ecological consequences to projected trends in ocean deoxygenation. |
| first_indexed | 2024-09-23T17:07:11Z |
| format | Article |
| id | mit-1721.1/100568 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T17:07:11Z |
| publishDate | 2016 |
| publisher | Copernicus GmbH |
| record_format | dspace |
| spelling | mit-1721.1/1005682024-05-15T05:38:26Z Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century Srain, B. Pantoja, S. Lange, C. B. McKay, J. Salamanca, M. Munoz, P. Sepulveda, Julio C Summons, Roger E Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Sepulveda, Julio Summons, Roger Everett We reconstructed oxygenation changes in the upwelling ecosystem off Concepcion (36° S), Chile, using inorganic and organic proxies in a sediment core covering the last ca. 110 years of sedimentation in this area. Authigenic enrichments of Mo, U and Cd were observed between ca. 1935 and 1971 CE, implying a prolonged period with predominantly more reduced conditions in bottom waters and surface sediments. Significant positive correlations between redox-sensitive metals, algal sterols, biomarkers of micro-aerophilic and anaerobic microorganisms, and archaeal glycerol dialkyl glycerol tetraethers point to a tight coupling among bottom water O[subscript 2] depletion and increased primary and export production. The time interval with low O[subscript 2] of ca. 35 years seems to follow low-frequency interdecadal variation of the Pacific Decadal Oscillation, and it may have resulted in O[subscript 2] depletion over the entire continental shelf off Concepción. Taking this together with the concurrent increase in sedimentary molecular indicators of micro-aerophilic and anaerobic microbes, we can suggest that changes in oxygenation of the water column are reflected by changes in microbial community. This study can inform our understanding of ecological consequences to projected trends in ocean deoxygenation. Center for Oceanographic Research in the Eastern South Pacific (COPAS) (Grant FONDAP 15010007) Center for Oceanographic Research in the Eastern South Pacific (COPAS) (Sur-Austral Program PFB-31) Gordon and Betty Moore Foundation (Grant 1661) MIT International Science and Technology Initiatives. MIT-Chile Seed Fund NASA Astrobiology Institute 2016-01-04T13:47:09Z 2016-01-04T13:47:09Z 2015-10 2015-10 Article http://purl.org/eprint/type/JournalArticle 1726-4189 http://hdl.handle.net/1721.1/100568 Srain, B., S. Pantoja, J. Sepulveda, C. B. Lange, P. Munoz, R. E. Summons, J. McKay, and M. Salamanca. “Interdecadal Changes in Intensity of the Oxygen Minimum Zone Off Concepcion, Chile (~36° S), over the Last Century.” Biogeosciences 12, no. 20 (October 22, 2015): 6045–6058. https://orcid.org/0000-0002-7144-8537 en_US http://dx.doi.org/10.5194/bg-12-6045-2015 Biogeosciences Creative Commons Attribution http://creativecommons.org/licenses/by/3.0/ application/pdf Copernicus GmbH Copernicus Publications |
| spellingShingle | Srain, B. Pantoja, S. Lange, C. B. McKay, J. Salamanca, M. Munoz, P. Sepulveda, Julio C Summons, Roger E Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title | Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title_full | Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title_fullStr | Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title_full_unstemmed | Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title_short | Interdecadal changes in intensity of the oxygen minimum zone off Concepcion, Chile (~36° S), over the last century |
| title_sort | interdecadal changes in intensity of the oxygen minimum zone off concepcion chile 36° s over the last century |
| url | http://hdl.handle.net/1721.1/100568 https://orcid.org/0000-0002-7144-8537 |
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