FN Archimer Export Format
PT J
TI First observations of seasonal bottom water deoxygenation off the Gironde estuary (Bay of Biscay, North East Atlantic)
BT 
AF Dubosq, Nicolas
   Schmidt, Sabine
   Sudre, Joel
   Rigaud, Sylvain
   Lamarque, Bastien
   Danilo, Martin
   Grémare, Antoine
   Deflandre, Bruno
AS 1:1;2:2;3:3;4:4;5:1;6:1;7:1;8:1;
FF 1:;2:;3:;4:;5:;6:;7:;8:;
C1 Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, Pessac, France
   CNRS, Univ. Bordeaux, Bordeaux INP, EPOC, UMR 5805, Pessac, France
   CNRS, UAR CPST, La Seyne sur mer, France
   Université de Nîmes, EA 7352 CHROME, Nîmes, France
C2 UNIV BORDEAUX, FRANCE
   CNRS, FRANCE
   CNRS, FRANCE
   UNIV NIMES, FRANCE
SI TOULON
SE INSU
IN DOAJ
IF 3.7
TC 1
UR https://archimer.ifremer.fr/doc/00797/90897/96539.pdf
   https://archimer.ifremer.fr/doc/00797/90897/96540.zip
LA English
DT Article
CR JERICOBENT
   MAGMA
BO Côtes De La Manche
DE ;deoxygenation;continental shelf;seasonal evolution;stratification;Bay of Biscay;dissolved oxygen
AB Although not systematically considered as oxygen minimum zones, River-dominated Ocean Margins are sensitive to oxygen depletions. For example, the continental shelf off the Gironde, which flows into the Bay of Biscay, had not yet been studied from this perspective although recent simulations suggested that this area should already have experienced deoxygenations in recent decades. To fill this gap, profiles of temperature, salinity and dissolved oxygen were performed in the water column of the continental shelf off the Gironde during seven cruises distributed over the different seasons between 2016 and 2021. Turbidity, chlorophyll-a and pH were also measured during some of these cruises. In winter, the water column was slightly stratified due to high river flows. Then, a seasonal thermal stratification was present from spring to autumn. Similarly, dissolved oxygen showed a seasonal dynamic with: a well-oxygenated water column in winter, an oxygen oversaturation in the first 20 meters during the spring bloom, and then a progressive oxygen depletion in bottom waters until reaching an oxygen saturation minimum down to 45% in autumn. These deoxygenations are explained by the seasonal stratification that isolates the bottom waters from spring to autumn, and are likely enhanced by the advection of deoxygenated waters from the north of the Bay of Biscay and the settling of the organic matter produced in surface waters. A better understanding of these processes in the context of global warming undoubtedly requires better documentation of dissolved oxygen variability through the implementation of a long-term and continuous in situ monitoring. 
PY 2022
PD OCT
SO Frontiers in Marine Science
SN 2296-7745
PU Frontiers Media SA
VL 9
UT 000874690400001
DI 10.3389/fmars.2022.1006453
ID 90897
ER

EF