seanoe:95886 Schmidt Sabine CNRS, UMR5805 EPOC, France sabine.schmidt@u-bordeaux.fr 2025-09-19 ISO 19115:2003/19139 1.0 Temperature, salinity, dissolved oxygen, suspended particulate matter and fluorescence in surface waters of the Charente estuary (North East Atlantic, France) 2023-07-22 2025-09-19 Schmidt Sabine, Diallo Ibrahima (2023). Temperature, salinity, dissolved oxygen, suspended particulate matter and fluorescence in surface waters of the Charente estuary (North East Atlantic, France). SEANOE. https://doi.org/10.17882/95886 There are at least a dozen small hyper-turbid estuaries facing the Bay of Biscay, geographically situated between the two major estuaries of the Gironde and the Loire. MAGEST and SYVEL high-frequency multi-site monitoring revealed that the Loire, and to a lesser extent the Gironde, are subject to summer hypoxia. These observations raised the question of the potential occurrence of hypoxia in the small estuaries in between, motivating an investigation of dissolved oxygen in one of them, the Charente estuary. Oxygen and salinity sensors were placed at L'Houmée (2019), Tonnay-Charente (2018; 2019), Rochefort (2020; 2021; 2022), Martrou (2020) during summer, the most critical period for dissolved oxygen; a multiparameter probe was placed at Tonnay-Charente from April to November 2020. Longitudinal investigations along the estuary axis were also carried out during the summers of 2018 and 2019. All the measurements were acquired at 0.5 ± 0.2 meters below the surface. The dataset enabled us to identify the occurrence of summer hypoxia and an oxygen depletion zone in the Charente estuary. These results resulted in the implementation of high-frequency monitoring at Tonnay-Charente, operational since November 2020. This work was a contribution to the project QUEtSCHE (trajectoires de la QUalité des eaux et du fonctionnement des écosystèmes des EStuaires aquitains face au CHangEment climatique) funded by the OASU (Aquitaine Observatory of the Sciences of the Universe) and the AEAG (Agence de l’Eau Adour Garonne). Schmidt Sabine CNRS, UMR5805 EPOC, France sabine.schmidt@u-bordeaux.fr Diallo Ibrahima Rectorat de Bordeaux SEANOE https://www.seanoe.org/data/00847/95886/illustration.gif The SAMBAT multiparameter probe on the floating pontoon of Tonnay-Charente in 2020 estuary Charente surface water temperature salinity dissolved oxygen suspended particle fluorescence Chemical oceanography Dissolved oxygen Fluorescence Salinity Sea temperature Suspended matter ODATIS aggregation parameters and Essential Variable names 2025-07-29 geonetwork.thesaurus.external.theme.NVS.OD1 Chemical oceanography SeaDataNet Parameter Disciplines 2025-07-29 geonetwork.thesaurus.external.parameter.NVS.P08 /Observational data/in-situ Type de jeux de donnée ODATIS 2024-10-15 geonetwork.thesaurus.local.theme.type_jeux_donnee CC-BY (Creative Commons - Attribution) Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay) 2024 Copernicus GmbH Schmidt Sabine Diallo Ibrahima Iris 10.5194/bg-21-1785-2024 Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)  2023 Copernicus GmbH Schmidt Sabine Diallo Ibrahima I. 10.5194/bg-2023-150 oceans -1.2 -0.65 45.85 46.0 2018-07-19 2020-11-16 CSV https://www.seanoe.org/data/00847/95886/data/103782.csv WWW:DOWNLOAD-1.0-link--download Quality controlled data Salinity, temperature and dissolved oxygen in surface water at L'Houmée - 523 KB https://www.seanoe.org/data/00847/95886/data/103783.csv WWW:DOWNLOAD-1.0-link--download Quality controlled data Salinity, temperature, dissolved oxygen, suspended particulate matter and fluoresence in surface water at Tonnay-Charente - 3 MB https://www.seanoe.org/data/00847/95886/data/103784.csv WWW:DOWNLOAD-1.0-link--download Quality controlled data Salinity, temperature and dissolved oxygen in surface water at Rochefort - 1 MB https://www.seanoe.org/data/00847/95886/data/103785.csv WWW:DOWNLOAD-1.0-link--download Quality controlled data Salinity, temperature and dissolved oxygen in surface water at Martrou - 242 KB https://www.seanoe.org/data/00847/95886/data/103786.csv WWW:DOWNLOAD-1.0-link--download Quality controlled data Longitudinal transects in the Charente estuary in summer 2018 and 2019 - 12 KB https://doi.org/10.17882/95886 WWW:LINK-1.0-http--metadata-URL DOI of the product https://www.seanoe.org/data/00847/95886/ rel-canonical Seanoe Measurements were taken using HOBO U26 Dissolved Oxygen and U24 Conductivity/Salinity loggers, except at Tonnay-Charente in 2020 where a SAMBAT multiparameter probe (NKE Instrumentation, France) was deployed. The measured parameters are temperature (−-5 to +35°C; ± < 1%), salinity (range 0.1 -42; ± < 5%), turbidity (Turner Designs CYCLOPS-7; 0 - 3000 NTU; ± < 5%) converted in suspended particulate matter (SPM using a NTU-SPM rating curve established for Charente SPM, dissolved oxygen (0 - 20 mg L-1;  ±0.1 mg L-1) and fluorescence (Turner Designs CYCLOPS-70 - 50 µg L-1; ± < 5%).