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Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis

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dc.contributor.author Monteiro, Pedro MS en_US
dc.contributor.author Roychoudhury, AN en_US
dc.date.accessioned 2007-02-07T06:09:55Z en_US
dc.date.accessioned 2007-06-07T10:09:55Z
dc.date.available 2007-02-07T06:09:55Z en_US
dc.date.available 2007-06-07T10:09:55Z
dc.date.copyright en_US
dc.date.issued 2005-10 en_US
dc.identifier.citation Monteiro, PMS and Roychoudhury, AN. 2005. Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis. Estuarine, Coastal and Shelf Science, vol 65, 2 January, pp 123-134 en_US
dc.identifier.issn 0272-7714 en_US
dc.identifier.uri http://hdl.handle.net/10204/1575 en_US
dc.identifier.uri http://hdl.handle.net/10204/1575
dc.description.abstract St. Helena Bay, is a retention zone located in the southern Benguela upwelling system, and is an important fish nursery. However, it suffers from seasonal bottom water hypoxia causing major economic losses. Anoxic conditions are linked to sulfide fluxes from bottom sediments defined by a high sedimentation rate of organic matter. It is proposed that trace metals may play an important role in alleviating part of the ecological stress by forming sulfide complexes in such systems. A spatially intensive data set of sediment biogeochemical characteristics showed that POC (Particular organic carbon) and trace metals were accumulating in the central zone of the Bay. Furthermore, trace metal concentrations were strongly correlated with both POC and Al. To explain the observed biogeochemical relationships, a hypothesis was proposed, the hypothesis linked the upwelling retention hydrodynamics, primary productivity and sediment trace metal distribution. Trace metals are incorporated into phytoplankton cells in the euphotic zone but rapidly sediment along with particulate organics, on their senescence. Both, the biological pump and the dispersion of particulates are primarily controlled by the hydrodynamics prevalent within St. Helena Bay, which also governs the retention zone in the shadow of one of the major upwelling cells. The dynamics of entrainment-stratification drives the productivity, while a residual cyclonic gyre concentrates the surface productivity within the bay. Bed-shear stresses spatially constrain the accumulation of biogenic organic matter, which governs the trace metal biogeochemistry of the sediments, along a narrow terrigenous mud belt. en_US
dc.format.extent 708945 bytes en_US
dc.format.mimetype application/pdf en_US
dc.language.iso en en_US
dc.publisher Elsevier Science Ltd en_US
dc.rights Copyright: 2005 Elsevier Science Ltd en_US
dc.source en_US
dc.subject Organic carbon en_US
dc.subject Upwelling retention hydrodynamics en_US
dc.subject Sediment ecosystems en_US
dc.subject Retention Zones en_US
dc.subject St. Helena Bay - South Africa en_US
dc.subject Environmental sciences en_US
dc.subject Benguela upwelling ecosystem en_US
dc.title Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis en_US
dc.type Article en_US
dc.identifier.apacitation Monteiro, P. M., & Roychoudhury, A. (2005). Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis. http://hdl.handle.net/10204/1575 en_ZA
dc.identifier.chicagocitation Monteiro, Pedro MS, and AN Roychoudhury "Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis." (2005) http://hdl.handle.net/10204/1575 en_ZA
dc.identifier.vancouvercitation Monteiro PM, Roychoudhury A. Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis. 2005; http://hdl.handle.net/10204/1575. en_ZA
dc.identifier.ris TY - Article AU - Monteiro, Pedro MS AU - Roychoudhury, AN AB - St. Helena Bay, is a retention zone located in the southern Benguela upwelling system, and is an important fish nursery. However, it suffers from seasonal bottom water hypoxia causing major economic losses. Anoxic conditions are linked to sulfide fluxes from bottom sediments defined by a high sedimentation rate of organic matter. It is proposed that trace metals may play an important role in alleviating part of the ecological stress by forming sulfide complexes in such systems. A spatially intensive data set of sediment biogeochemical characteristics showed that POC (Particular organic carbon) and trace metals were accumulating in the central zone of the Bay. Furthermore, trace metal concentrations were strongly correlated with both POC and Al. To explain the observed biogeochemical relationships, a hypothesis was proposed, the hypothesis linked the upwelling retention hydrodynamics, primary productivity and sediment trace metal distribution. Trace metals are incorporated into phytoplankton cells in the euphotic zone but rapidly sediment along with particulate organics, on their senescence. Both, the biological pump and the dispersion of particulates are primarily controlled by the hydrodynamics prevalent within St. Helena Bay, which also governs the retention zone in the shadow of one of the major upwelling cells. The dynamics of entrainment-stratification drives the productivity, while a residual cyclonic gyre concentrates the surface productivity within the bay. Bed-shear stresses spatially constrain the accumulation of biogenic organic matter, which governs the trace metal biogeochemistry of the sediments, along a narrow terrigenous mud belt. DA - 2005-10 DB - ResearchSpace DP - CSIR KW - Organic carbon KW - Upwelling retention hydrodynamics KW - Sediment ecosystems KW - Retention Zones KW - St. Helena Bay - South Africa KW - Environmental sciences KW - Benguela upwelling ecosystem LK - https://researchspace.csir.co.za PY - 2005 SM - 0272-7714 T1 - Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis TI - Spatial characteristics of sediment trace metals in an eastern boundary upwelling retention area (St. Helena Bay, South Africa): A hydrodynamic-biological pump hypothesis UR - http://hdl.handle.net/10204/1575 ER - en_ZA


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