The ICES Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) has developed an assessment framework based on the life history trait longevity, to evaluate the benthic impact of fisheries at the regional scale. In order to apply this framework to the Mediterranean sea, several Mediterranean longevity databases were merged together with existing North-East Atlantic ones to develop a common database. Longevity was fuzzy coded into four longevity classes: <1, 1-3, 3-10 and >10 years. Both benthic mega and macrofauna organisms are included in this dataset. Further details about both the purpose and the methodology may be found in ICES (2022) and Cuyvers et al. (2023). The result of the final dataset merging is one dataset containing the fuzzy coded average longevity (and standard deviation) for 2264 taxa and for each, the number of databases used. 

Long-term time series of coliform bacteria concentration (fecal coliform or Escherichia coli) in shellfish in four submarine areas (North Sea/Channel, Britany, Atlantic, Mediterranean).

The PHYTOBS-MARCOBOLO dataset comprises long-term time series on marine microphytoplankton, from 2003 to 2021, along the entire French metropolitan coastline. Microphytoplankton data cover microscopic taxonomic identifications and counts. The PHYTOBS-MARCOBOLO dataset corresponds to a dataset extracted from the PHYTOBS network (DOI:10.17882/85178). The PHYTOBS network provides the scientific community and stakeholders with validated and qualified data on the biomass, abundance and composition of marine microphytoplankton in coastal and lagoon waters, with the aim of supporting scientific research. PHYTOBS-MARCOBOLO is a dataset used as part of the Horizon Europe MARCO-BOLO project (https://marcobolo-project.eu/), in which we are currently working to understand and analyze multi-decadal trends in coastal and marine biodiversity on a European scale. The PHYTOBS-MARCOBOLO dataset gathers data from 18 sampling sites, selected from the PHYTOBS-Network dataset according to requirements of time series quality and geographical location of sampling sites established as part of the MARCO-COLO project. This dataset was also formatted according to a template imposed for the European project.

The SAPERCHAIS program (Suivi des Apports marins et terrigènes dans la mer des PERtuis CHarentAIS) was developed to monitor environmental fluctuations in the Pertuis Charentais Sea by an hydrological watchfulness. Seven stations, representatives of terrigenous or marine inputs, have been followed from 2011 to 2014. From north to south, the main four rivers of the Pertuis, Le Lay, La Sèvre, Charente and Seudre, and the three maritime inputs of each strait, Breton, Antioche and Maumusson. At each station, temperature and salinity were recorded in situ, just below the surface, with a high frequency resolution (10 minutes) . This work was supported by grants from Région Poitou-Charentes and European Regional Development Fund to the Ifremer "Developpement Durable de la Pêche et de la Conchyliculture" project.

The Arcachon Bay is a unique and ecologically important meso-tidal lagoon on the Atlantic coast of south-west France. The Arcachon Bay has the largest area of dwarf seagrass (Z. noltei) in Europe, the extent of which was stable in their extent between the 1950s and 1990s, but a decline in seagrass was observed in mid-2000. The decline of Zostera (seagrass) may have a significant impact on sedimentation in this coastal ecosystem rich in marine life. Interface cores were collected in September 2022 to determine sediment and mass accumulation rates (SAR, MAR) in the Arcachon Bay. Ten study areas were selected, distributed over most of the areas where seagrass meadows are actually observed. Two sites were visited each time, one with the presence of Zostera noltei in good condition (Healthy) and the other where the sediment was bare (Bare). Maximum water heights during spring tides range from 3.44 m for the deepest site (Garrèche) to 2.09 m for the shallowest site (Fontaines). A total of 20 sediment cores were sampled and carefully extruded every 1 cm from the top to the bottom of the core. The sediment layers were used to determine dry bulk density and selected radioisotope activities: DBD, 210Pb, 226Ra, 137Cs, 228Th and 40K expressed as %K). 

The diet and stable isotopic (i.e. δ15N and δ13C values) compositions of eels have been studied during each season of 2019 with a fyke net in six estuaries located along the French coast of the eastern English Channel (Slack, Wimereux, Liane, Canche, Authie and Somme estuaries) (10.1371/journal.pone.0270348).

Data collected by the Spindrift 2 Sails of Change vessel during its attempt at the round-the-world sailing record, the Jules Verne Trophy. More information at https://spindrift-racing.com/fr/.

The West Gironde Mud Patch (WGMP) is a mud deposit located 25 km from the mouth of the Gironde Estuary in the Bay of Biscay. This 4-metre-thick clay-silt feature, which extends over an area of 420 km2, is found at depths between 30 and 80 meters. The main objectives of the JERICObent7 cruise, in July 2019, were to characterise the evolution of the WGMP’s benthic ecosystem in terms of its sedimentary, biogeochemical and ecological properties and to reconstruct climate variations and identify potential anthropogenic impacts over the last few centuries. To this end, a precise chronological framework was established for the sedimentary archives of the last few decades using 210Pbxs (T1/2 = 22.3 years). Interface cores were collected at stations 1, 3 and 4 along a cross-shelf transect. Twin Kullenberg cores were collected at sites 3 and 4 for geochemical (KGL) and palaeoceanographic (JB7-ST) investigations. Each interface core was carefully extruded at 0.5 cm intervals from the top of the core to 4 cm, and then at 1 cm intervals until the bottom was reached. Kullenberg cores were only collected at sites 3 and 4. Depending on their intended use, the Kullenberg cores were sampled at different resolutions, the depth of each sediment layer corresponded to the depth from the top of the core. These layers were then used to determine the dry bulk density and radioisotope activities of interest (210Pb, 226Ra,  228Th, 137Cs, 40K). Excess 210Pb was used to establish the realignment and chronological framework of the interface and Kullenberg cores.

Three saltmarshes, Aiguillon, Brouage, Fier d'Ars, located in the Pertuis-Charentais Sea along the south-west coast of France, were studied to evaluate their sediment and mass accumulation rates (SAR; MAR) based on 210Pb and 137Cs profiles in sediments. Coastal saltmarshes play indeed an essential role in providing services such as coastal protection and supporting biodiversity. Saltmarshes are also critical environments for the accumulation of sedimentary organic carbon (blue carbon). However, the number of studies on saltmarshes remains underrepresented compared to studies on mangroves and seagrass. This work is a contribution to the effort to document sediment and mass accumulation rates of saltmarshes.A total of 16 1m sediment cores were collected in the three saltmarshes (Aiguillon, Brouage, Fier d'Ars) in 2021 and 2022 using an Eijkelkamp stainless steel peat sampler. Each sediment core was sampled every 1 cm from the top to the bottom of the core. The sediment layers were used to determine dry bulk density and selected radioisotope activities (210Pb, 226Ra, 137Cs, 228Th, 137Cs). Combining excess 210Pb and 137Cs has allowed to establish a reliable chronology of sediment deposition on a multidecadal timescale.

SUCHIMED 2021 is the 10th campaign for monitoring chemical contamination and its evolution in the Mediterranean Sea. It has been designed as a platform supporting various surveillance and research activities, with the main pillar being the RINBIO network, which involves active biosurveillance through mussel caging. Regarding chemical contamination, the main results of this campaign are as follows: In Occitania region: - Chronic presence of DDT for 20 years. - Detection of terrigenous markers (Mn, As) between the mouths of the Aude and Hérault rivers, along with contamination of sediments near Port-La-Nouvelle by HAP and TCE (Pt). In PACA region: - PCB markers detected between the Rhône River and Marseille (in all matrices), originating from multiple sources with no significant changes over the past 20 years. - HAP contamination in sediments of the industrial-port zone in Fos. - Presence of TBT at the Carry-le-Rouet station above ecologically acceptable concentrations (EAC), to be confirmed in the next campaign. - Detection of metallic elements and HAP in sediments near the Marseille urban area, partly in plankton, along with TCE near the Cortiou wastewater treatment plant outfall. - Chronic marking of PCB, HAP, metals (Hg, Pb, Cu, TCE), PBDE, and/or organotin compounds (TBT) in Toulon Bay, showing no significant temporal trend over two decades for the first five compounds. - Detection of Cr, Mn, and Ni in the water column and HAP in sediments near the Var River mouth, with differences in contamination between matrices raising questions about organic matter origin. - Metal (including Pb) and HAP marking in the water column and sediment in Villefranche Bay. Around Corsica: - Strong influence of the island's geological background (i.e., high Cr and Ni content) on obtained concentrations. - Chronic marking of Cu in the water column in the ports of Porto-Vecchio and Bonifacio, stable over time, with HAP, metals (Hg, Pb, Zn), and to a lesser extent, PCB detection in Bonifacio sediment. - Marking of HAP and TCE in the sediment of the Bastia coastline. - Detection of Pb and TCE at the Golo River mouth. - Contamination of the Canari site with metals (Cr and Ni in the water column, Cu in sediment), and notably, confirmed ecotoxicity likely linked to these elements. The 2021 campaign highlighted the feasibility of researching effects on caged mussels using biomarkers. Lysosomal markers, less sensitive to trophic differences, proved to best reflect the general stress state of organisms related to their contamination. The study of trophic transfers appears to confirm the decrease in most metallic elements (Cr, Cu, Fe, Mn, Ni, Pb) and HAP, bioamplification of Hg and PCB, and specific bioaccumulation of certain elements by organisms (e.g., As or Zn by mussels, HAP by plankton). Finally, the campaign revealed the presence of micro and mesoplastics at almost all sampled sites. The measured microplastic values align with concentrations observed in the western Mediterranean, with a trend towards reduction based on available 10-year data.