COAST-HF - data and metadata from the MOLIT buoy in the Vilaine Bay

Date 2022-10
Temporal extent 2011-03-02 -2021-12-31
Author(s) Retho Michael1, Quemener LoicORCID2, Le Gall Christian2, Repecaud MichelORCID2, Souchu Philippe1, Gabellec Raoul1, Manach Soazig1
Affiliation(s) 1 : Ifremer, Laboratoire Environnement Ressources Morbihan-Pays de Loire, 8 rue François Toullec 56100 Lorient et rue de l’Ile d’Yeu 44311 Nantes, France
2 : Ifremer, Laboratoire Détection, Capteurs et Mesures, Centre Bretagne ZI de la Pointe du Diable CS 10070 29280 Plouzané, France
DOI 10.17882/46529
Publisher SEANOE
Keyword(s) MOLIT, buoy, monitoring system, high frequency, Vilaine Bay, sea temperature, practical salinity, dissolved oxygen, turbidity, fluorescence, two measurement levels (subsurface and bottom)

The MOLIT (Mer Ouverte LITorale) measuring station developed and implemented by Ifremer (French Research Institute for Exploitation of the sea) is a moored buoy equipped with biological and physico-chemical sensors working in continuous and autonomous conditions. The system is located South of Brittany in the Vilaine Bay, one of the areas of the Atlantic coast most threatened by eutrophication.

The buoy was deployed during the period of primary productivity, from March to October from 2011 to 2017 and has been deployed throughout the year since March 2018.

The measuring station is equipped with high performance systems for seawater analysis and near real time data transmission. This station performs measurements at two levels : subsurface = LEVEL1 and bottom (1 m above the water-sediment interface) = LEVEL3. This system records with a high frequency resolution (one hour), the following parameters : sea temperature, practical salinity, dissolved oxygen, turbidity and fluorescence.

The data were qualified into several levels : 0-No QC performed, 1-Good data, 2-Probably good data, 3-Probably bad data, 4-Bad data, 5-Value changed, 7-Nominal value, 8-Interpolated value, 9-Missing value. The quality level is indicated in the data file in a column “QC” for each parameter. Some fluorescence data has been corrected and appears in the “fluorescence adjusted” parameter. The information that led to the quality level are synthesized in an annual report qualification.

The MOLIT station is a component of the national high frequency observing network COAST-HF ( from the ILICO research infrastructure (

Licence CC-BY-NC
Utilisation A user of MOLIT data exported from Coriolis data centre is expected to read and understand this manual and the documentation about the data, as they contain essential information about data format, quality and accuracy. Each user should at least use the “how to cite” formula when valorising data. The data can be viewed on the website:
Sensor metadata

Qualification report data

File Size Format Processing Access Key
1 MB CSV Quality controlled data Access on demand 46297
4 MB CSV Quality controlled data Access on demand 79136
2011-2021 data 49 MB CSV Quality controlled data Open access 96488

Coriolis : In situ data for operational oceanography

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How to cite 

Retho Michael, Quemener Loic, Le Gall Christian, Repecaud Michel, Souchu Philippe, Gabellec Raoul, Manach Soazig (2022). COAST-HF - data and metadata from the MOLIT buoy in the Vilaine Bay. SEANOE.