Observation series

SOMLIT-Portzic

The SOMLIT-Portzic observation series

The SOMLIT-Brest hydrological quality monitoring system has been operated since 1998 by IUEM/UBO/CNRS to characterise the general state of water bodies in the Brest Bay – Mer d’Iroise coastal system at weekly intervals. It aims to observe and understand the evolution of the environment in response to climate change and to detect the impact of human activities.

It is the local version of the national service SOMLIT (Service d’Observation des Milieux Littoraux) labelled by INSU/CNRS, which consists of 12 observation stations distributed throughout the French coastline. It is an integral part of the ILICO coastal research infrastructure.

Partners

The site

SOMLIT-Brest monitoring was implemented at the Ste-Anne-du-Portzic observation site (48°21’32.17” N, 4°33’07.21” W), at the entrance to the Brest harbour, at the interface with the Iroise Sea. The sample was taken at an average coefficient (70 ± 10) under open sea conditions: it is representative of the waters of the Iroise Sea.

Monitoring

Sampling is carried out from the tidal tower, at a depth of 2 m, for a water column of 9 m. About fifteen parameters are measured according to standard procedures validated by the entire network community. The measurements are carried out in accordance with the ISO 17025 standard.

The SOMLIT-Brest series, which has been conducted continuously for several decades, provides insight into the processes responsible for the temporal variability of the state of the coastal environment. Interpretation allows the identification of response patterns in terms of trends, breaks, cyclicity and associated delay.

Parameters

Technical

Analysis Manager

Temperature, Salinity, PAR

Seabird probe (SBE19+)

Emilie Grossteffan

Dissolved oxygen

Winkler titler

Emilie Grossteffan

Glass electrode

Emilie Grossteffan

Ammonium

Spectrophotometry

Emilie Grossteffan

Nitrates, Nitrites and Silicates

Sequential flow measurement

Emilie Grossteffan

Soluble Reactive Phosphate (PO4)

Spectrophotometry

Emilie Grossteffan

Suspended matter

Weighing

Emilie Grossteffan

Carbon and Particulate Organic Nitrogen

Elementary analysis

Jérémie Devesa

Chlorophyll a / Pheopigments

Fluorimetry

Emilie Grossteffan

Phytoplankton

Identification, counting and biovolume

Gaspard Delebecq

Isotopes δ13C and δ15N

Mass spectrometry

Nicolas Savoye

Pico- and Nano-plankton

Cytometry

Christophe Lambert

Access to data

All data from the SOMLIT-Portzic series are available on the portal of the national SOMLIT website.

Access the data on the SOMLIT website

Publications

In terms of scientific production, SOMLIT-Brest data have been used for a long time as complementary data to research data for studies conducted in Brest roadstead: more than 70 publications and 30 UBO theses have used them directly or indirectly. More recently, their length, covering two decades, makes it possible to use them statistically as a time series indicating long-term climate impact in the marine environment.

List of publications on HAL