Record Details
Field | Value |
---|---|
Title | Inter-decadal changes in the intensity of the Oxygen Minimum Zone off Concepción, Chile (~ 36° S) over the last century |
Names |
Srain, B.
(creator) Pantoja, S. (creator) Sepúlveda, J. (creator) Lange, C. B. (creator) Muñoz, P. (creator) Summons, R. E. (creator) McKay, J. (creator) Salamanca, M. (creator) |
Date Issued | 2015 (iso8601) |
Note | This discussion paper has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG. The published article is copyrighted by the author(s) and published by Copernicus Publications on behalf of the European Geosciences Union. The published article can be found at: http://www.biogeosciences.net/ |
Abstract | We reconstructed oxygenation changes in the Oxygen Minimum Zone of the upwelling ecosystem off Concepción (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. 1935–1971 CE indicating a prolonged period of more reduced conditions in bottom waters and surface sediments. Significant positive correlations (p < 0.05; Spearman) between redox sensitive metals, algal sterols, biomarkers of anaerobic microorganisms, and archaeal glycerol dialkyl glycerol tetraether indicated a coupling among bottom water oxygen depletion, and increased primary and export production, suggesting that the period with low O₂ of ca. 35 years, follows low frequency inter-decadal variation of the Pacific Decadal Oscillation, which may have resulted in O₂ depletion over the entire continental shelf off Concepción. Taken together with the concurrent increase in sedimentary molecular indicators of anaerobic microbes allow us to suggest that the prokaryote community has been influenced by changes in oxygenation of the water column. |
Genre | Article |
Access Condition | http://creativecommons.org/licenses/by/3.0/us/ |
Identifier | Srain, B., Pantoja, S., Sepúlveda, J., Lange, C. B., Muñoz, P., Summons, R. E., McKay, J., and Salamanca, M. (2015) Inter-decadal changes in the intensity of the Oxygen Minimum Zone off Concepción, Chile (~ 36° S) over the last century, Biogeosciences Discussions, 12, 6003-6035, doi:10.5194/bgd-12-6003-2015 |