The SSLAMM is a MIO laboratory based at the Endoume marine station (Figure 1) with a dual objective: firstly, to measure several hydrological, biogeochemical, microbiological and chemical variables in seawater simultaneously at a single site, using automated sensors and regular sampling.
The second objective of the SSLAMM is to provide an instrumented platform and an environment conducive to the development and validation of sensors, with automated data acquisition. The SSLAMM can also accommodate researchers and students for research and data linkage projects, in optimal working conditions while benefiting from natural seawater taken in situ.
Figure 1 Left: Building 4 of the Endoume marine station and the calanque, the pumping point is located at a depth of 4 m at the end of the dyke in the centre of the calanque.
anque. Right: cleaning the high-pressure nozzle
Since Wednesday 18 September 2019, the 300 kg peristaltic pump that brings seawater from the calanque to the laboratory has been working. The water arrives at a pressure of <1 bar with a flow rate close to 15 dm3/min, distributed to 6 taps. The seawater thus flows continuously into the laboratory. The OSU PYTHEAS diving department installed the strainer and cleans it weekly. The seawater circuit has been entirely designed to have a minimal influence on the biological and physico-chemical quality of the seawater pumped (peristaltic pump to avoid cavitation, trace-metal clean materials), with mechanical cleaning in the hydraulic section between the pump and the sampling point (high-pressure ferret, figure 1) and chemical cleaning in the laboratory section.
The first automated sensors have been installed, enabling continuous analyses of gaseous mercury in the atmosphere (since 21 May 2019) and in seawater (Lars-Eric Heimbürger-Boavida, CEM team, figure 2), the counting and resolution of phytoplankton functional groups using automated flow cytometry (Melilotus Thyssen, CYBELE team, figure 2), and measurements of temperature and salinity using a NKE probe (SAM platform). The high-frequency strategy will enable us to study not only diurnal and seasonal cycles, but also the effects of impulse events such as gales, storms, rain and pollution on the structuring of microbial communities and their processes, chemical elements and their transformations. In the pipeline are sensors for measuring biogenic oxygen using a MIMS spectrometer (Dominique Lefèvre, Olivier Grosso), resolution of heterotrophs (prokaryotes and protozoa by cytometry using an automated marking module (Gérald Grégori and Michel Denis)), and pH and pCO2 sensors currently being updated. Fluorimeters, an automated nutrient salt analyser, trace metal sensors and phytoplankton physiological activity sensors are planned.
This SSLAMM project has been made possible thanks to support from ERDF and MISTRALS funds, AMU, OSU PYTHEAS and MIO. SSLAMM is under the scientific direction of Melilotus Thyssen, and the technical direction of Olivier Grosso (MIO, CYBELE team).
Figure 2 Left: Equilibrator and dissolved mercury detector. Right= Flow cytometer for phytoplankton analysis at the individual cell level.