Reference : Benthic remineralization in the northwest European continental margin (northern Bay o...
Scientific journals : Article
Life sciences : Environmental sciences & ecology
Life sciences : Aquatic sciences & oceanology
http://hdl.handle.net/2268/81232
Benthic remineralization in the northwest European continental margin (northern Bay of Biscay)
English
Suykens, Kim [Unité d’Océanographie Chimique, Université de Liège, B-4000 Liège, Belgium > > > >]
Schmidt, Sabine [EPOC, UMR 5805, Université Bordeaux 1, Talence, France > > > >]
Delille, Bruno mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
Harlay, Jérôme mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
Chou, Lei [Laboratoire d’Océanographie Chimique et Géochimie des Eaux, Faculté des Sciences, Université Libre de Bruxelles, B-1050 Brussels, Belgium > > > >]
De Bodt, Caroline [> >]
Fagel, Nathalie mailto [Université de Liège - ULg > Département de géologie > Argiles, géochimie et environnements sédimentaires >]
Borges, Alberto mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique >]
2011
Continental Shelf Research
Pergamon Press - An Imprint of Elsevier Science
31
644-658
Yes (verified by ORBi)
International
0278-4343
Oxford
United Kingdom
[en] We report a dataset of sediment characteristics and biogeochemical fluxes at the watersediment
interface at the northwest European continental margin (northern Bay of Biscay).
Cores were obtained in June 2006, May 2007 and 2008, at 18 stations on the shelf break (120
to 180 m), and at 2 stations on the continental slope (520 m and 680 m). Water-sediment
fluxes of dissolved oxygen (O2), total alkalinity (TA), nitrate (NO3-), and dissolved silicate
(DSi) were measured at a total of 20 stations. Sediment characteristics include: grain size,
chlorophyll-a (Chl-a) and phaeopigment (Phaeo) content, particulate organic (POC) and
inorganic (PIC) carbon content, and lead-210 (210Pb) and thorium-234 (234Th) activities.
Sediments were sandy (fine to coarse) with organic matter (OM) (1.0 - 4.0 %) and Chl-a (0.01
- 0.95 μg g-1) contents comparable to previous investigations in the same region, and a
relatively high PIC fraction (0.8 - 10.2 %). Water-sediment O2 fluxes (-2.4 to -8.4 mmol O2
m-2 d-1) were low compared to other coastal environments and correlated well with OM and
Chl-a content. 234Th activity profiles indicated that Chl-a sediment content was mainly
controlled by physical mixing processes related to local hydrodynamics. The correlation
between water-sediment fluxes of O2 and NO3- indicated a close coupling of
nitrification/denitrification and total benthic organic carbon degradation. Dissolution of
biogenic silica (0.05 to 0.95 mmol m-2 d-1) seemed uncoupled from organic carbon
degradation, as characterized by water-sediment O2 fluxes. The link between water-sediment
fluxes of TA and O2 indicated the occurrence of metabolic driven dissolution of calcium
carbonates (CaCO3) in the sediments (~ 0.33 ± 0.47 mmol m-2 d-1) which represented ~ 1 % of
the pelagic calcification rates due to coccolithophores measured during the cruises. These
CaCO3 dissolution rates were below those reported in sediments of continental slopes and of
the deep ocean, probably due to the high over-saturation with respect to CaCO3 of the water
column overlying the continental shelf sediments of the northern Bay of Biscay. Rates of total
benthic organic carbon degradation were low compared to water column rates of primary
production and aphotic community respiration obtained during the cruises.
Researchers ; Professionals ; Students
http://hdl.handle.net/2268/81232

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