Matches in SemOpenAlex for { <https://semopenalex.org/work/W3090305008> ?p ?o ?g. }
Showing items 1 to 78 of
78
with 100 items per page.
- W3090305008 abstract "<p>The Benguela upwelling system (BUS) offshore Namibia is among the most productive ocean regions worldwide and is a globally important reservoir of biodiversity and biomass. The forcing of cold, nutrient-rich deep waters up the coastal shelf leads to high rates of primary productivity in surface waters, intense carbon remineralization and consequently to (bottom water) oxygen depletion on the shelf that varies temporally and spatially with the intensity of the upwelling.<br>Recurring events of deoxygenation have a severe impact on marine ecosystems, for instance increased mortality and altered biogeochemical cycles of key elements such as carbon (C), iron (Fe), phosphorus (P) and sulfur (S). Therefore, it is crucial that we establish a clear mechanistic framework of the impact of oxygen depletion on (global) biogeochemical cycles, not only to allow for the reconstruction of climate-ocean feedbacks in upwelling regions in the past, but to enable predictions of future behavior.<br>During an expedition with <em>RV Pelagia</em> in February of 2019, we collected water column and sediment samples from the shelf and slope off Namibia (100 to 1517 m water depth, bottom water O<sub>2</sub> between 0.5 and 175 &#181;mol L<sup>-1</sup>) and measured nutrient fluxes in on-board sediment incubations to understand the early diagenetic behavior of those key elements and trace metals underlying the (periodically) oxygen-depleted waters of the BUS.<br>We analyzed dissolved concentrations as well as solid-phase speciation of key elements such as iron (Fe), manganese (Mn), phosphorus (P) and sulfur (S) to understand the chemical and physical processes controlling their distribution along the depth/redox-transect.<br>Our results show intense P cycling on the shelf, as evidenced by very high pore-water P concentrations, an enhanced efflux of PO<sub>4</sub> to suboxic bottom waters and indications of phosphorite formation at depth in the sediment. N/P ratios well below Redfield indicate N depletion and (relative) P accumulation in the water column, a shift in nutrient stoichiometry that can impact the composition of microbial communities in such waters. Meanwhile, the slope sediments are overlain by oxic bottom waters, retain P more efficiently and exhibit N/P ratios close to Redfield stoichiometry.<br>The capacity of the sediment to buffer toxic sulfide and prevent its release to the water column was dependent on the abundance of sulfide oxidizers at the sediment surface. Furthermore, the variable accumulation of sulfide affected Fe speciation and sedimentary P retention.<br>Overall, we show an intimate coupling between sedimentary cycles of essential elements in the Benguela upwelling system, a stark contrast between shelf and slope environments that is further enhanced by local variation of oxygen depletion and a very strong role of microbes in driving the cycles.</p>" @default.
- W3090305008 created "2020-10-08" @default.
- W3090305008 creator A5018123390 @default.
- W3090305008 creator A5036503406 @default.
- W3090305008 creator A5077037670 @default.
- W3090305008 date "2020-03-23" @default.
- W3090305008 modified "2023-09-25" @default.
- W3090305008 title "Coupled benthic cycling of iron, phosphorus and sulfur in the Benguela upwelling system" @default.
- W3090305008 doi "https://doi.org/10.5194/egusphere-egu2020-19291" @default.
- W3090305008 hasPublicationYear "2020" @default.
- W3090305008 type Work @default.
- W3090305008 sameAs 3090305008 @default.
- W3090305008 citedByCount "0" @default.
- W3090305008 crossrefType "posted-content" @default.
- W3090305008 hasAuthorship W3090305008A5018123390 @default.
- W3090305008 hasAuthorship W3090305008A5036503406 @default.
- W3090305008 hasAuthorship W3090305008A5077037670 @default.
- W3090305008 hasConcept C107872376 @default.
- W3090305008 hasConcept C111368507 @default.
- W3090305008 hasConcept C122846477 @default.
- W3090305008 hasConcept C127313418 @default.
- W3090305008 hasConcept C130309983 @default.
- W3090305008 hasConcept C142796444 @default.
- W3090305008 hasConcept C149348798 @default.
- W3090305008 hasConcept C151730666 @default.
- W3090305008 hasConcept C178790620 @default.
- W3090305008 hasConcept C184751465 @default.
- W3090305008 hasConcept C185592680 @default.
- W3090305008 hasConcept C18903297 @default.
- W3090305008 hasConcept C2780134711 @default.
- W3090305008 hasConcept C2780275952 @default.
- W3090305008 hasConcept C2816523 @default.
- W3090305008 hasConcept C33275205 @default.
- W3090305008 hasConcept C39432304 @default.
- W3090305008 hasConcept C510538283 @default.
- W3090305008 hasConcept C71915725 @default.
- W3090305008 hasConcept C77942228 @default.
- W3090305008 hasConcept C83042747 @default.
- W3090305008 hasConcept C86803240 @default.
- W3090305008 hasConceptScore W3090305008C107872376 @default.
- W3090305008 hasConceptScore W3090305008C111368507 @default.
- W3090305008 hasConceptScore W3090305008C122846477 @default.
- W3090305008 hasConceptScore W3090305008C127313418 @default.
- W3090305008 hasConceptScore W3090305008C130309983 @default.
- W3090305008 hasConceptScore W3090305008C142796444 @default.
- W3090305008 hasConceptScore W3090305008C149348798 @default.
- W3090305008 hasConceptScore W3090305008C151730666 @default.
- W3090305008 hasConceptScore W3090305008C178790620 @default.
- W3090305008 hasConceptScore W3090305008C184751465 @default.
- W3090305008 hasConceptScore W3090305008C185592680 @default.
- W3090305008 hasConceptScore W3090305008C18903297 @default.
- W3090305008 hasConceptScore W3090305008C2780134711 @default.
- W3090305008 hasConceptScore W3090305008C2780275952 @default.
- W3090305008 hasConceptScore W3090305008C2816523 @default.
- W3090305008 hasConceptScore W3090305008C33275205 @default.
- W3090305008 hasConceptScore W3090305008C39432304 @default.
- W3090305008 hasConceptScore W3090305008C510538283 @default.
- W3090305008 hasConceptScore W3090305008C71915725 @default.
- W3090305008 hasConceptScore W3090305008C77942228 @default.
- W3090305008 hasConceptScore W3090305008C83042747 @default.
- W3090305008 hasConceptScore W3090305008C86803240 @default.
- W3090305008 hasLocation W30903050081 @default.
- W3090305008 hasOpenAccess W3090305008 @default.
- W3090305008 hasPrimaryLocation W30903050081 @default.
- W3090305008 hasRelatedWork W17782377 @default.
- W3090305008 hasRelatedWork W19312824 @default.
- W3090305008 hasRelatedWork W21610429 @default.
- W3090305008 hasRelatedWork W23301785 @default.
- W3090305008 hasRelatedWork W24565438 @default.
- W3090305008 hasRelatedWork W25658194 @default.
- W3090305008 hasRelatedWork W30616325 @default.
- W3090305008 hasRelatedWork W33381345 @default.
- W3090305008 hasRelatedWork W36579360 @default.
- W3090305008 hasRelatedWork W38063677 @default.
- W3090305008 isParatext "false" @default.
- W3090305008 isRetracted "false" @default.
- W3090305008 magId "3090305008" @default.
- W3090305008 workType "article" @default.