SOMLIT-Portzic time series (French Research Infrastructure ILICO): long-term core parameter monitoring in the Bay of Brest and Iroise Sea.

The SOMLIT-Portzic time-series data characterize the hydrology of the Bay of Brest – Mer d’Iroise ecosystem, located at 48°N (western Brittany). Weekly measurements have been undertaken since 1998 by the IUEM/UBO/CNRS. The SOMLIT-Portzic observation station is a part of the French monitoring network SOMLIT (, accredited by the CNRS as a national Earth Science Observatory (Service National d’Observation : SNO). It aims to detect the long-term evolution of these ecosystems including both natural and anthropogenic forcings.

Implemented on the Ste-Anne-du-Portzic location (48°21'32.17'' N, 4°33'07.21'' W), the SOMLIT-Portzic observation station is among the oldest long-term coastal observation stations of the French Research Infrastructure dedicated to coastal ocean observations (known as ILICO,

The high-frequency hydrological COAST-HF-Iroise time-series and the microphytoplankton PHYTOBS-Portzic time-series are also monitored at this location.

SOMLIT-Portzic samples are collected at 2m-depth of a 9m water column, at high tide, during slack water, with an average coefficient of 70 ± 10. Samples collected are analysed for more than 20 core parameters: SST, SSS, dissolved oxygen, pH, ammonia, nitrates, nitrites, phosphates, silicates, suspended matter, particulate organic carbone, particulate organic nitrogen, chlorophyll, delta15N, delta13C; pico- and nano- plankton; CTD-PAR-profile.

The SOMLIT network quality management system is in line with the ISO/IEC 17025:2017 standard: “General requirements for the competence of testing and calibration laboratories”. Further information on standard operating procedures for sample collection and data acquisition are available at: For more information on the quality flagging scheme:


Cross-discipline, Environment, Fisheries and aquaculture, Human activities, Physical oceanography, Biological oceanography, Chemical oceanography


Environmental time series, Hydrological and biogeochemical data, coastal system evolution, climate impact, Coastal ecology


48.644228N, 48.206804S, -4.188374E, -5.193623W


A SBE-19Plus-V2 profiler is used for CTDPAR measurements. To guarantee best performances, the sensors return to the constructor every two years for calibration.


Alternative access to data

237 KoCSVQuality controlled data
232 KoCSVQuality controlled data
1 MoCSVQuality controlled data
How to cite
Rimmelin-Maury Peggy, Grossteffan Emilie, Devesa Jeremy, Perennou Morgan, Delebecq Gaspard, Lambert Christophe, Leynaert Aude, Klein Cecile (2022). SOMLIT-Portzic time series (French Research Infrastructure ILICO): long-term core parameter monitoring in the Bay of Brest and Iroise Sea. SEANOE.

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