FN Archimer Export Format
PT J
TI Withdrawn. Linking sediment biodegradability with its origin in shallow coastal environments
BT 
AF Louis, Justine
   Laverman, Anniet M.
   Jardé, Emilie
   Pannard, Alexandrine
   Liotaud, Marine
   ANDRIEUX-LOYER, Francoise
   Gruau, Gérard
   Caradec, Florian
   Rabiller, Emilie
   Lebris, Nathalie
   Jeanneau, Laurent
AS 1:1,3;2:1;3:2;4:1;5:2;6:3;7:2;8:3;9:3;10:1;11:3;
FF 1:PDG-ODE-DYNECO-PELAGOS;2:;3:;4:;5:;6:PDG-ODE-DYNECO-PELAGOS;7:;8:PDG-ODE-DYNECO-PELAGOS;9:PDG-ODE-DYNECO-PELAGOS;10:;11:;
C1 Centre National de la Recherche Scientifique (CNRS), ECOBIO – UMR 6553, Université de Rennes 1, 35042 Rennes, France
   Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes – UMR 6118, Université de Rennes 1, 35042 Rennes, France
   Ifremer, DYNECO PELAGOS, ZI Pointe du Diable, 29280 Plouzané, France
C2 CNRS, FRANCE
   CNRS, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-ODE-DYNECO-PELAGOS
IN DOAJ
TC 0
UR https://archimer.ifremer.fr/doc/00738/85014/89968.pdf
   https://archimer.ifremer.fr/doc/00738/85014/95025.pdf
LA English
DT Article
AB In coastal areas and estuaries, such as those encountered in the western part of France (Brittany region), the recycling of carbon and nutrients from sediments can participate in the development of micro and macro-algal blooms with harmful consequences for these ecosystems. One of the main processes controlling this recycling is the microbial mineralization of sedimentary organic matter (SOM). Mineralization is controlled by the origin, quantity and accessibility of the SOM, three factors whose relative importance remain, however, poorly quantified, mainly due to the great diversity of OM sources in coastal areas. The first objective of the present work was to assess the variability of the SOM origin at the regional scale representative of the complexity of the sources likely to be involved. The second objective was to determine the link between the SOM origin and its biodegradability, and how the OM sources can drive nutrient dynamics at the sediment-water interface. To this end, a broad sediment sampling campaign was carried out on Brittany mudflats, particularly affected by the eutrophication, during the spring period. A total of 200 samples were collected at 45 sites. They were characterized by their porosity and grain-size, as well as their chemical composition through elemental, isotopic and molecular biomarker analysis. A wide range of OM sources were identified in the sediments, including both natural (bacteria, algae, macrophytes, terrestrial plants), and anthropogenic (combustion products, crude oil, petroleum products – e.g. from the processing of crude oil at refineries- and fecal matter) sources. Sediment slurry incubations were carried out to determine the spatial variability of potential mineralization rates under oxic conditions. In addition, the measurements of NH4+ and PO4 fluxes at the sediment-water interface were made from sediment core incubations under realistic redox conditions of sediment. The physical and chemical sedimentary characteristics explained 58 % of the variability of mineralization rates under oxic conditions, with a negligible independent effect of the SOM origin (3 %). Conversely, under insitu redox conditions, the prevalent role of SOM origin over quantity/accessibility on the sediment biodegradability was highlighted with a significant effect 5 and 1.5 fold higher on the PO4 and NH4+ fluxes respectively. The anthropogenic inputs from the watershed to the coastal sediment, through agricultural runoff and/or sewages discharge, seem to significantly drive the nutrient dynamics at the sediment-water interface. Higher values of NH4+ and PO4 fluxes were measured for the sediment with a chemical composition impacted by human activities. 
PY 2021
PD JAN
SO Biogeosciences Discussions
SN 1810-6285
PU Copernicus GmbH
DI 10.5194/bg-2021-318
ID 85014
ER

EF