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A new device to follow temporal variations of oxygen demand in deltaic sediments: the LSCE benthic station
Author(s) -
Toussaint Flora,
Rabouille Christophe,
Cathalot Cécile,
Bombled Bruno,
Abchiche Abdel,
Aouji Oualid,
Buchholtz Gilles,
Clemençon Aurélien,
Geyskens Nicolas,
Répécaud Michel,
Pairaud Ivane,
Verney Romaric,
TisnératLaborde Nadine
Publication year - 2014
Publication title -
limnology and oceanography: methods
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.898
H-Index - 72
ISSN - 1541-5856
DOI - 10.4319/lom.2014.12.729
Subject(s) - benthic zone , environmental science , biochemical oxygen demand , hydrology (agriculture) , oceanography , sediment , hypoxia (environmental) , chemical oxygen demand , turbidity , organic matter , oxygen , geology , ecology , environmental engineering , geomorphology , chemistry , geotechnical engineering , organic chemistry , wastewater , biology
A new benthic station equipped with oxygen microelectrodes and environmental sensors was developed by Laboratoire des Sciences du Climat et de L'Environnement (LSCE) and Division Technique of the Institut National des Sciences de L'Univers (DT‐ INSU) to perform in situ time series monitoring of sediment oxygen demand, linked to the mineralization of organic matter. The time series typically cover periods of 2‐ 3 months, with a base frequency of 1 set of oxygen profiles per day. The profiling head assessed the lateral heterogeneity of the sediment oxygen demand at the beginning of the time series over a 0.8‐ m long rectangle to discriminate spatial and temporal variability. A continuous recalibration is performed using a moored oxygen optode anchored to the benthic station together with a set of environmental sensors. These sensors (turbidity, temperature, salinity, and oxygen) can trigger a high‐ frequency profiling mode to investigate the fate of particulate organic matter delivered during floods, resuspension, and deposition events. Deployments of the benthic station were performed in the Rhone River subaqueous delta (Mediterranean Sea). We show that “stable” periods (when neither floods nor storms occur) were characterized by a stable oxygen demand. In the case of resuspension events, an increase of the sediment oxygen demand by a factor of 2‐ 3 with a relaxation time of 1 day was observed, indicating that the new benthic station can adequately capture the impact of resuspension events on the oxygen demand in deltaic sediments.