FN Archimer Export Format
PT J
TI Impact of an exceptional winter flood on benthic oxygen and nutrient fluxes in a temperate macrotidal estuary: Potential consequences on summer deoxygenation
BT 
AF Hulot, Vivien
   Metzger, Edouard
   Thibault de Chanvalon, Aubin
   Mouret, Aurelia
   Schmidt, Sabine
   Deflandre, Bruno
   Rigaud, Sylvain
   Beneteau, Eric
   Savoye, Nicolas
   Souchu, Philippe
   Le Merrer, Yoann
   Maillet, Grégoire M.
AS 1:1;2:1;3:2;4:1;5:3;6:3;7:4;8:1;9:3;10:5;11:5;12:1;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:PDG-ODE-LITTORAL-LERMPL;11:PDG-ODE-LITTORAL-LERMPL;12:;
C1 UMR 6112 LPG, Université d’Angers, Université de Nantes, Université du Mans, CNRS, Angers, France
   Université de Pau et des Pays de l’Adour, E2S UPPA, CNRS, IPREM, Pau, France
   Université de Bordeaux, CNRS, Bordeaux INP, UMR5805 EPOC, Pessac, France
   Univ. Nîmes, UPR 7352 CHROME, Nîmes, France
   IFREMER – LER, MPL, Nantes, France
C2 UNIV ANGERS, FRANCE
   UNIV PAU & PAYS ADOUR, FRANCE
   UNIV BORDEAUX, FRANCE
   UNIV NIMES, FRANCE
   IFREMER, FRANCE
SI NANTES
SE PDG-ODE-LITTORAL-LERMPL
IN WOS Ifremer UPR
   DOAJ
   copubli-france
   copubli-univ-france
IF 3.7
TC 1
UR https://archimer.ifremer.fr/doc/00821/93289/99958.pdf
   https://archimer.ifremer.fr/doc/00821/93289/99959.pdf
LA English
DT Article
CR REBELRED
BO Thalia
DE ;estuary;water sediment exchanges;hypoxia;oxides-phosphorus interactions;flood
AB Despite 20 years of control on eutrophication, episodes of summer hypoxia still occur in the Loire estuary, impacting water quality and posing a key scientific and management challenge. This work aimed to quantify the contribution of the benthic compartment to hypoxia in the Loire estuary by direct measurement of water–sediment fluxes and an in-depth understanding of the seasonal variations of oxides and phosphorus stocks. During the summer’s low-discharge period, results show that the iron oxide-rich deposit is stable under hypoxic conditions, limiting the release of dissolved phosphorus into the overlying water column. The high nitrate content of the water column appears to be an important oxidizer of iron during hypoxic periods, limiting dissolved phosphorus leakage and aggravation of hypoxia. During the exceptional winter flood, significant sediment erosion associated with bubbling phenomena (attributed to methane efflux) created severe fractures in the sediment and stimulated water–sediment exchange. During the following months, these fractures were progressively filled, which decreased the intensity of benthic fluxes. However, due to the high residence time in the water during the summer period, a simple model demonstrated that benthic contributions were sufficient to directly (by direct oxygen consumption) or indirectly (by promoting ammonia oxidation) affect the oxygen stock in the water column during the low-discharge period. Our study demonstrates the importance of the benthic compartment in the occurrence of hypoxia and the obvious lack of knowledge to illustrate and model the biogeochemical functioning of the estuary. 
PY 2023
PD FEB
SO Frontiers In Marine Science
SN 2296-7745
PU Frontiers Media SA
VL 10
UT 000942175100001
DI 10.3389/fmars.2023.1083377
ID 93289
ER

EF