IPOCOM project: CTD data along the French Mediterranean coast, NW Mediterranean, spring 2024.

This dataset contains the CTD data collected during the IPOCOM project (Fish inventory using environmental DNA), between 21/05/2024 and 10/06/2024, along the French Mediterranean coast (PACA and Occitanie regions), jointly by the Andromède océanologie (France) and MARBEC MARine Biodiversity, Exploitation and Conservation (France) teams.
The CTD data were obtained using RBR concerto3 autonomous logger from Victoria IV trimaran belonging to Scopra, France and chartered by the University of Montpellier.
133 transects (1 was 2.5-km long and 132 were 5-km long) were performed along the deepest local limit of the Posidonia oceanica seagrass meadow from Menton to Cerbère, latitude 42.3-43.9°N and longitude 2.7-7.6°E.
In PACA, the sampling depth was -26 m in mean (±10 m) and in Occitanie the mean depth was -7 m (±5 m), 5 m above the seabed in mean for both regions.
The sensors measured and recorded conductivity (mS/cm), temperature (°C), pressure (dBar), dissolved O2 concentration (µmol/L) and turbidity (NTU). Other parameters were derived from the previous measurements: sea pressure (dbar) removing atmospheric pressure, depth (m) simplifying and using density parameter, salinity (PSU) or Practical Salinity Scale (PSS-78), speed of sound (m/s) based on UNESCO algorithm, specific conductivity (µS/cm) and dissolved O2 saturation (%).
All parameters were measured or calculated at depths ranging from – 0.5 m to -56 m (Table 1). Recordings were made every 0.5 seconds (2 Hz frequency). The accuracy, specified by the manufacturer, was ±0.003mS/cm for conductivity, ±0.002°C for temperature, ±0,1 dbar for pressure (Depth), a maximum of ±2μmol/L or ±1.5% for dissolved O2 concentration and saturation. RBR Concerto3 was factory calibrated before.
The downloadable files are a csv of CTD probe data, a geopackage of all transects spatialized with mean, min, max, sd and median for all parameters of CTD probe, a pdf showing the evolution of all the variables, accompanied by a text explaining the problems encountered.