Key physico-chemical parameters (salinity, temperature, turbidity and dissolved oxygen) were measured in surface water during longitudinal transects in the Loire and Gironde estuaries in summers 2017 and 2018. This objective of this work was to determine the distribution of the dissolved oxygen and to detect potential severe desoxygenation. The transects were scheduled in order to begin the measurements at high tide from a site located upstream of an area where severe deoxygenation have been already been reported. Then, the transect was realised by sailing at low speed downstream with a multiparameter probe SAMBAT, maintained at 0.5 m below the surface, that collected a measurement every 2 minutes.

The ARCHYD dataset, which have been collected since 1988, represents the longest long-term hydrologic data sets in Arcachon Bay. The objectives of this monitoring programme are to assess the influence of oceanic and continental inputs on the water quality of the bay and their implications on biological processes. It also aims to estimate the effectiveness of management policies in the bay by providing information on trends and/or shifts in pressure, state, and impact variables. Sampling is carried on stations spread across the entire bay, but since 1988, the number and location of stations have changed slightly to better take into account the gradient of ocean and continental inputs. In 2005, the ARCHYD network was reduced to 8 stations that are still sampled by Ifremer to date. All the stations are sampled at a weekly frequency, at midday, alternately around the low spring tide and the high neap tide. Data are complementary to REPHY dataset. Physico-chemical measures include temperature, salinity, turbidity, suspended matters (organic, mineral), dissolved oxygen and dissolved inorganic nutrients (ammonium, nitrite+nitrate, phosphate, silicate). Biological measures include pigment proxies of phytoplankton biomass and state (chlorophyll a and phaeopigment).

The upper branch of the Atlantic Meridional Overturning Circulation (AMOC) plays a critical role in ocean circulation and climate change, yet its variability during the last glacial period is poorly documented. Here, we investigate the northward-flowing Glacial Eastern Boundary Current (GEBC) in the North Atlantic, known today as the European Slope Current, and representing the easternmost portion of the upper branch of the AMOC. Based on flow speed (sortable silt, XRF) and radiogenic/stable isotopic records, we show that Dansgaard-Oeschger (D/O) interstadials (stadials) correspond to a faster (weaker) GEBC during the ~50-15 ka period. This, by analogy to present-day conditions, suggests enhanced (reduced) strength of the subpolar gyre and, by extension, of northern-sourced water production and AMOC during D-O interstadials (stadials). Concomitant fluctuations of both the European Ice Sheet and the GEBC between ~30 and 17 ka suggest an active role of the upper branch of AMOC in the poleward transport of heat and freshwater to the northern North Atlantic, with direct impacts on deep water formation and AMOC strength. Our GEBC reconstruction is the first physical (non-chemical) record documenting dynamic upper AMOC variability at high resolution in the eastern basin of the North Atlantic. Together with the deep North Atlantic records of northern-sourced water export, they confirm the central role of the AMOC in the generation of abrupt climate changes.

Good Environmental Status assessment (GES) for descriptor 8 (contaminants, D8) of the Marine Strategy Framework Directive (MSFD) is reached when concentrations of contaminants are at levels not giving rise to pollution effects. It is described by 4 criteria among which the first one focus on the concentration of the contaminants in the environment (criteria 1 of the D8, D8C1). The environmental status for D8 in France includes assessment of contaminant concentrations in sediment, bivalves, fish, birds, mammals to cover the French marine area the continental shelf from the coast line). The 8 tables below present the assessment of the chemical contamination in sediment and bivalves on the coastal area of the 4 French marine subregions for D8 as part of the 2024 GES assessment. These tables report the status and temporal trends of each station x matrice x substance triplet in each of the 4 French marine subregions. Explanation on how to read the cells is given in the “read file”. The environmental assessment for D8 in France can be found in Mauffret al., 2023 (DOI:10.13155/97214). It includes 17 national indicator assessments, 4 OSPAR indicators and integrated assessment in selected assessment units at the level of the criteria 1 and 2. 

The data file present detailed individual congener/compound concentrations  for a large variety of hydrophobic organic contaminants including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), legacy and alternative brominated flame retardants (BFRs) and per- and polyfluoroalkyl substances (PFASs) in meso- and bathypelagic organisms collected in the Bay of Biscay, northeast Atlantic, in October 2017. The studied species include 3 crustacean species (Pasiphaea sivado, Sergia robusta, Ephyrina figueirai) and 11 fish species (Xenodermichthys copei, Searsia koefoedi, Myctophum punctatum, Notoscopelus kroeyeri, Lampanyctus crocodilus, Argyropelecus olfersii, Arctozenus risso, Stomias boa, Serrivomer beanii, Chauliodus sloani, Aphanopus carbo). The organisms were collected at night during one single trawling using a 25 m vertical opening pelagic trawl in the deep scattering layer (ca 800 m depth in the water column; 1330 m bottom floor). This dataset was used in the article entitled "A large diversity of organohalogen contaminants reach the meso- and bathypelagic organisms in the Bay of Biscay (northeast Atlantic)" published in Marine Pollution Bulletin.

The Mediterranean Sea is generally described as an oligotrophic area where primary productivity is limited to a few coastal environments with nutrient-enriched fluvial input. However, several studies have revealed that the hydrology of the western Mediterranean has major seasonal productive patterns linked either to significant riverine input or to seasonal upwelling cells. This study aims to: i) discuss organic microfossils (i.e. pollen and dinoflagellate cyst assemblages, as well as other non-pollen palynomorphs) from two different productive areas of the western Mediterranean Sea, and ii) examine the importance of the interconnections between marine and continental influences responsible for modern palynomorph distributions. Based on 25 samples from the Gulf of Lion (GoL) and Algerian Margin, this study key findings are: i) that GoL marine productivity is driven by the combination of discharges from the Rhône River and seasonal upwelling mechanisms, ii) that the strong productive pattern of the northern African coast is driven by water density front mixings and related upwellings. These two patterns are discussed in the light of major links that provide a better understanding of the signatures of marine and continental bio-indicators. The dinocyst Lingulodinium machaerophorum can be considered as a tracer of Rhône River plume influence in the GoL. Brigantedinium taxa are shown to be upwelling-sensitive in both studied areas. Typical differences in vegetation across the north–south climate gradient in the western Mediterranean Basin are highlighted by the larger ratio of Euro-Siberian to Mediterranean pollen taxa in the northern sector. Synoptic maps also illustrate the complex interactions of environmental drivers determining the distributions of continental and marine palynomorphs in the western Mediterranean Sea.

Particularly suited to the purpose of measuring the sensitivity of benthic communities to trawling, a trawl disturbance indicator (de Juan and Demestre, 2012, de Juan et al. 2009) was proposed based on benthic species life history traits to evaluate the sensibility of mega- and epifaunal community to fishing pressure known to have a physical impact on the seafloor (such as dredging and bottom trawling). The selected biological traits were chosen as they determine vulnerability to trawling: mobility, fragility, position on substrata, average size and feeding mode that can easily be related to the fragility, recoverability and vulnerability ecological concepts. Life history traits of species have been defined from the BIOTIC database (MARLIN, 2014) and from information given by Le Pape et al. (2007), Brindamour et al. (2009) and Garcia (2010). For missing life history traits, additional information from literature has been considered. The five categories retained are life history functional traits that were selected based on the knowledge of the response of benthic taxa to trawling disturbance (de Juan and Demestre, 2012). They reflect respectively the possibility to avoid direct gear impact, to benefit from trawling for feeding, to escape gear, to get caught by the net and to resist trawling/dredging action, each of these characteristics being either advantageous or sensitive to trawling. Then, to allow quantitative analysis, a score was assigned to each category: from low vulnerability (0) to high vulnerability (3). The five categories scores were then summed for each taxon (the highly vulnerable taxon could reach the maximum score is 15) and this value may be considered as a species index of sensitivity to trawling disturbance. The scores of 812 taxa commonly found in bottom trawl by-catch in the southern North Sea, English Channel and north-western Mediterranean were described.

The West Gironde Mud Patch (WGMP) is a 420-km2 mud belt in the Bay of Biscay, located 25 km off the mouth of the Gironde estuary. This clay-silt feature of 4 m in thickness extends between 30 and 75m water depth, surrounded by the sands and gravels that cover the North Aquitaine continental shelf. Interface cores were collected during JERICOBent-1 cruise (October 2016; Deflandre (2016) doi.org/10.17600/16010400) along two cross-shelf transects for a total of 9 sites. Each sediment core was carefully extruded every 0.5 cm from the top core to 4 cm and every 1 cm below until the core bottom. The sediment layers were used to determine dry bulk density, grain size and selected radioisotope activities (210Pb, 226Ra, 137Cs, 228Th, K).

Marine microfossils (dinoflagellate cysts and planktonic foraminifera) and geochemical (XRF-Ti/Ca)-based climatic records from a core located off the Fleuve Manche (FM) paleo-mouth (MD13-3438) have revealed that sustained warm summer sea surface temperatures (SSTs) during sub-millennial climate changes within HS1 (~18–14.7 ka) may have played a key role in the FM regime related to the European Ice Sheet (EIS) melting rate. In this study, we have analyzed the MD13-3438 pollen content over the HS1 at a mean resolution of ~50 years to test whether vegetation-based air temperatures were coupled to SSTs face to this rapid climate variability. First, our results highlight two major phases of pollen sources at site MD13-3438, preventing the pollen record to be interpreted as a continuous record of the evolution of vegetation and climate occupying a single watershed across HS1. The first phase, i.e. the HS1-a interval (~18–16.8 ka), is marked by strong occurrences of boreal pollen taxa (especially Picea-Abies). Considering their spatial distribution and the coalescence of the British and Scandinavian ice sheets into the North Sea during the Last Glacial Maximum, these taxa probably originated from the North European Plain, i.e., eastern FM tributaries (east of the Rhine River), where cool-humid conditions generally prevailed. Then, the second phase, i.e. the HS1-b interval (~16.8–14.7 ka BP), is characterized by a deceleration of the EIS retreat and the drop of boreal pollen values at site MD13-3438 further signing a less influence of the upstream FM drainage system and thus a better characterization of pollen sources related with western FM tributaries. Superimposed to these two HS1 main phases, pollen fluctuations are concomitant with sub-millennial variability in the EIS deglaciation intensity. During the early HS1 (HS1-a), we discussed two short-term increases in the ratio between deciduous trees (Quercus-Corylus-Alnus) and herbaceous plants (Plantago-Amaranthaceae-Artemisia). These events were coeval with phases of increasing FM meltwater runoff and SST seasonality (i.e., dinocyst-based summer SST amplification). We associated these events with lower contribution of the upstream FM catchment as well as, possibly, atmospheric warming and regional sea-level positive oscillations. The HS1-b is composed of three main phases that appear more influenced by the downstream FM drainage system. HS1-b1 (16.8–16.3 ka BP) corresponds to the driest and coldest conditions west of the Rhine River. HS1-b2 (16.3–15.6 ka BP) is coeval with large arrivals of iceberg from the Hudson strait in the Bay of Biscay and thus likely to a major sea-level positive oscillation associated with a phase of FM valley reworking. HS1-b3 (15.6–14.7 ka BP) corresponds to persistent arid conditions that preceded the subsequent more humid conditions recorded from 14.7 ka BP at the start of the Bölling-Alleröd.

Since 2004, the Service facility SNAPO-CO2 (Service National d’Analyse des Paramètres Océaniques du CO2) housed by the LOCEAN laboratory (Paris, France) has been in charge for the analysis of Total Alkalinity (AT) and Total dissolved inorganic carbon (CT) of seawater samples on a series of cruises or ships of opportunity conducted in different regions in the frame of French projects. More than 44000 observations are synthetized in this work. Sampling was performed either from CTD-Rosette casts (Niskin bottles) or collected from the ship’s seawater supply (intake at about 5m depth). After completion of each cruise, discrete samples were returned back at LOCEAN laboratory and stored in a dark room at 4 °C before analysis generally within 2-3 months after sampling (sometimes within a week).  AT and CT were analyzed simultaneously by potentiometric titration using a closed cell (Edmond, 1970). Certified Reference Materials (CRMs) provided by Pr. A. Dickson (Scripps Institution of Oceanography, San Diego, USA) were used to calibrate the measurements. The same instrumentation was used for underway measurements during OISO cruises (https://doi.org/10.18142/228) and OISO AT-CT data for 1998-2018 in the South Indian Ocean added in this synthesis. The synthesis is organized in two files (one for Global ocean and the Coastal Zones, one for the Mediterranean Sea) with the same format: Cruise name, Ship name, day, month, year, hour, minute, second, latitude, longitude, depth, AT (µmol/kg), Flag-AT, CT (µmol/kg), Flag-CT, Temperature (°C), Flag-Temp, Salinity (PSU), Flag-Salinity, nsample/cruise, nsample on file, sampling method.