The dataset includes age- and length-based catch per unit effort data for commercial fish species collected by the French trawl survey EVHOE.

Understanding the dynamics of species interactions for food (prey-predator, competition for resources) and the functioning of trophic networks (dependence on trophic pathways, food chain flows, etc.) has become a thriving ecological research field in recent decades. This empirical knowledge is then used to develop population and ecosystem modelling approaches to support ecosystem-based management. The TrophicCS data set offers spatialized trophic information on a large spatial scale (the entire Celtic Sea continental shelf and upper slope) for a wide range of species. It combines ingested prey (gut content analysis) and a more integrated indicator of food sources (stable isotope analysis). A total of 1337 samples of large epifaunal invertebrates (bivalve mollusks and decapod crustaceans), zooplankton, fish and cephalopods, corresponding to 114 species, were collected and analyzed for stable isotope analysis of their carbon and nitrogen content. Sample size varied between taxa (from 1 to 52), with an average of 11.72 individuals sampled per species, and water depths ranged from 57 to 516 m. The gut contents of 1026 fish belonging to ten commercially important species: black anglerfish (Lophius budegassa), white anglerfish (Lophius piscatorius), blue whiting (Micromesistius poutassou), cod (Gadus morhua), haddock (Melanogrammus aeglefinus), hake (Merluccius merluccius), megrim (Lepidorhombus whiffiagonis), plaice (Pleuronectes platessa), sole (Solea solea) and whiting (Merlangius merlangus) were analyzed. The stomach content data set contains the occurrence of prey in stomach, identified to the lowest taxonomic level possible. To consider potential ontogenetic diet changes, a large size range was sampled. The TrophicCS data set was used to improve understanding of trophic relationships and ecosystem functioning in the Celtic Sea. When you use the data in your publication, we request that you cite this data paper. If you use the present data set (TrophicCS) for the majority of the data analyzed in your study, you may wish to consider inviting at least one author of the core team of this data paper to become a collaborator /coauthor of your paper.

Opportunistic macroalgae blooms (green tides) data are collected during monitoring surveys on the English Channel / Bay of Biscay French coasts since 2008 (Quadrige program code : BLOOMS). Protocols are implemented in the European Water Framework Directive.

As part of the marine water quality monitoring of the “Pertuis” and the “baie de l’Aiguillon” (France), commissioned by the OFB and carried out by setec énergie environnement, three monitoring stations were installed. Two of them were set up at the mouths of the Charente and Seudre rivers on February 6 and 27, 2019, respectively, while a third was deployed in the Bay of Aiguillon on March 24, 2021. The dataset presented here concerns the station installed in the Bay of Aiguillon. Measurements are organized into .csv files, with one file per year. Data is collected using a WiMO multiparameter probe, which records the following parameters: •    Temperature (-2 to 35 °C) •    Conductivity (0 to 100 mS/cm) •    Pressure (0 to 30 m) •    Turbidity (0 to 4000 NTU) •    Dissolved Oxygen (0 to 23 mg/L & 0 to 250 %) •    Fluorescence (0 to 500 ppb)  

The COAST-HF/Arcachon-Ferret time series characterizes the hydrology of the interface between the Arcachon lagoon, located in the South-Western France, and the Atlantic Ocean. A buoy belonging to Phares et Balises is instrumented with a multi-parametric probe that records sub-surface temperature, conductivity, depth, turbidity and fluorescence every 10 minutes since February 2018. It is opérated by the OASU and EPOC teams (Univ. Bordeaux/CNRS). COAST-HF (Coastal OceAn observing SysTem - High Frequency; www.coast-hf.fr) is a national observation network accredited by the CNRS as a national Earth Science Observatory (Service National d’Observation: SNO). It aims to federate and coordinate a set of 14 fixed platforms instrumented with high-frequency in situ measurements for key parameters of coastal waters. The COAST-HF/Arcachon-Ferret buoy is one of them. COAST-HF is part of the French Research Infrastructure dedicated to coastal ocean observations (RI ILICO, https://www.ir-ilico.fr). Data are transmitted to the Coriolis Côtier database (https://data.coriolis-cotier.org/). Data are raw data.

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. 

LOCEAN has been in charge of analyzing the isotopic composition of the dissolved inorganic carbon (DIC) in sea water collected during a series of cruises or ships of opportunity mostly in the southern Indian Ocean , the North Atlantic, and the equatorial Atlantic, but also in the Mediterranean Sea and in the equatorial Pacific. The LOCEAN sea-water samples for δ13CDIC were collected in 125/25 ml glass bottles until 2022/since then and poisoned with HgCl2 (1 ml of saturated solution) before storage in a dark room à 4°C until their measurement. The DIC was extracted from the seawater by acidification with phosphoric acid (H3PO4 85%) and CO2 gas that was produced was collected in a vacuum system following the procedure described by Kroopnick (1974). The isotopic composition of CO2 was determined using a dual inlet-isotopic ratio mass spectrometer (SIRA9-VG) by comparing the 13C/12C ratio of the sample to the 13C/12C ratio of a reference material, the Vienna-Pee Dee Belemnite (V-PDB). The isotopic composition is expressed in the δ-unit defined by Craig (1957)(method type 2).  Experience showed that samples older than 3-4 years are likely to have experienced conservation issues and have been dismissed. The mass spectrometer has worked very well until 2014-2015. Afterwards, its aging as well as the aging of the preparation line resulted in more data loss, and often less accurate results. The preparation line was renovated in 2019, and analyses in 2020 were run manually, often repeating the measurement a second time for each sample. Up to 2007-2008, δ13CDIC values have a precision of±0.01 ‰ (Vangriesheim et al.,2009) and a reproducibility of±0.02 ‰. After an interlaboratory comparison exercise led by Claire Normandeau (Dalhousie  University),  results  suggest  that  recent  LOCEAN  samples have a slightly poorer reproducibility (±0.04 ‰ ) as well as an offset of -0.13‰ (details available in Reverdin et al., ESSD 2018) that is confirmed by Becker et al. 2016 work by comparison with other cruises after removing the anthropogenic signal. Recent comparisons in early May 2021 with Orsay GEOPS facility samples suggest that the current offset is much smaller and might be +0.03‰. LOCEAN has installed in 2021 a new measurement device by coupling a Picarro G2131-I cavity ring down spectrometer (CRDS) with a CO2 extractor (Apollo SciTech) that will measure at the same time DIC (method type 3) (Leseurre, 2022). Since then, all water samples have been analyzed on this device. Part of the data set, as well as a scientific context and publications are also presented on the WEB site https://www.locean-ipsl.upmc.fr/oceans13c. Individual files correspond to regional subsets of the whole dataset. The file names are based on two letters for the region followed by (-) the cruise or project name (see below) followed by –DICisotopes, followed by either -s (surface data) or -b (subsurface data), and a version number (-V0, …): example SI-OISO-DICisotopes-s-V0; the highest version number corresponds to the latest update of the cruise/project data set, and can be directly downloaded. Earlier versions can be obtained on request, but are not recommended. The region two letters are the followings:   - SI: station and surface data in the Southern Indian Ocean that include cruises : INDIGO I (1985 – stn) (https://doi.org/10.17600/85000111) CIVA I (1993 – stn & surf) (https://doi.org/10.17600/93000870) (Archambeau et al., JMS 1998) ANTARES (1993 – stn & surf) (https://doi.org/10.17600/93000600) OISO (*) (since 1998 – stn & surf) (https://doi.org/10.18142/228) (Racapé et al., Tellus 2010, Leseurre, 2022)   - EA: station and surface data in the Tropical Atlantic Ocean that include cruises : EQUALANT (1999 & 2000 – surf) (https://doi.org/10.18142/98) EGEE (2005 to 2007 – stn & surf) (https://doi.org/10.18142/95) PIRATA (since 2013 – stn & surf) (https://doi.org/10.18142/14) EUMELI 2 (1991 – stn) (https://doi.org/10.17600/91004011)  (Pierre et al., JMS 1994) BIOZAIRE 3 (2003 – stn & surf ) (https://doi.org/10.17600/3010120) (Vangriesheim et al., DSRII, 2009) TARA-Microbiomes (2021 - stn & surf)   - NA : station and surface data in the North Atlantic Subpolar gyre that include cruises : OVIDE (**) (since 2002 – stn & surf) (https://doi.org/10.17882/46448) (Racapé et al., 2013) RREX (2017 – stn & surf) (https://doi.org/10.17600/17001400) SURATLANT (since 2010 - surf) (https://doi.org/10.17882/54517) (Racapé et al., BG 2014 ; Reverdin et al., ESSD 2018, Leseurre, 2022) NUKATUKUMA (since 2017- surf)   - MS: station data in the Mediterranean sea that include cruises : ALMOFRONT 1 (1991 – stn) (https://doi.org/10.17600/91004211) VICOMED 3 (1990 – stn) (https://doi.org/10.17600/90000711)   - PO: tropical Pacific that include cruises : PANDORA (2012 – stn) (https://doi.org/10.17600/12010050) ALIZE2 (1991 – stn & surf) (https://doi.org/10.17600/91002711) (Laube-Lenfant and Pierre, Oceanologica Acta 1994)   - SO: station and surface data in the Southern Ocean (except OISO) that include cruises: TARA-Microbiomes (2021-2022, stn & surf) AGULHASII-072022 (2022, stn) CONFLUENCE (1993-1994, stn)   - AO: station and surface data in the Arctic Ocean and nearby seas that include cruises: GREENFEEDBACK (2024, stn&surf) TCA (2024, stn) REFUGE ARCTIC (2024, stn) (*) The values for cruises OISO19, 21 and 22 are doubtful (for some, too low) and will require further investigation to find whether adjusted values can be proposed. (**) Some of the OVIDE cruises are also referred to as or GEOVIDE (in 2014), and BOCATS (in 2016). CATARINA, BOCATS1 and BOCATS2 (PID2019-104279GB-C21/AEI/10.13039/501100011033) cruises were funded by the Spanish Research Agency  The values of the OVIDE 2010 stations are doubtful (too low), but no particular error was found, and they have been left in the files.   Data The files are in csv format reported as: - Cruise name, station id, (bottle number), day, month, year, hour, minute, longitude, latitude, pressure (db), depth (m), temperature (°C), temperature qc, salinity (pss-78), salinity qc, d13CDIC, d13CDIC qc, method type - Temperature is an in situ temperature - Salinity is a practical salinity - Method type (1) acid CO2 extraction from helium stripping technique coupled to mass spectrometer, (2) acid CO2 extraction in a vacuum system coupled to mass spectrometer,(3) CO2 extractor (Apollo SciTech) coupled to CRDS measurements. Temperature qc, salinity qc, d13CDIC qc are quality indices equal to: - 0 no quality check (but presumably good data) - 1 probably good data - 2 good data - 3 probably bad data - 4 certainly bad data - 9 missing data (and the missing data are reported with an unlikely missing value)

The general objective of the PEACETIME cruise is to study the fundamental processes and their interactions at the ocean-atmosphere interface, occurring after atmospheric deposition (especially Saharan dust) in the Mediterranean Sea, and how these processes impact the functioning of the pelagic ecosystem. During the proposed 33 days cruise in the western and central Mediterranean Sea in May 2017, we will study the impact of atmospheric deposition on the cycles of chemical elements, on marine biogeochemical processes and fluxes, on marine aerosols emission and how ongoing changes will impact the functioning of Mediterranean Sea communities in the future. The cruise is designed to explore a variety of oligotrophic regimes. Combining in situ observations both in the atmosphere and the ocean, and in situ and minicosm-based on-board process studies, the 40 embarking scientists from atmosphere and ocean sciences will characterize the chemical, biological and physical/optical properties of both the atmosphere and the sea-surface microlayer, mixed layer and deeper waters. The PEACETIME strategy (season and cruise track) associated to a combination of dust transport forecasting tools and near real-time satellite remote sensing is designed to maximize the probability to catch a Saharan dust deposition event in a stratified water column in order to follow the associated processes in-situ. This coordinated multidisciplinary effort will allow us to fill the current weaknesses/lacks in our knowledge of atmospheric deposition impact in the ocean and feedbacks to the atmosphere in such oligotrophic systems. As a key joint-project between MERMEX and CHARMEX : The PEACETIME project comes in the scope of the regional multidisciplinaryprogramme MISTRALS (Mediterranean Integrated STudies at Regional And Local Scales ), which aims at predicting the evolution of this region following strong expected changes in climate and human pressures. In this framework, the PEACETIME project constitutes a key joint project between the ChArMEx (the Chemistry-Aerosol Mediterranean Experiment) and MERMEx (Marine Ecosystems Response in the Mediterranean Experiment) initiatives, enabling to gather communities of atmospheric chemists and marine biogeochemists around the common question of assessing the impact of atmospheric deposition on the marine biogeochemical processes and air-sea exchanges.

210Pb, 226Ra and 137Cs were measured by non-destructive gamma spectrometry on marine sediment cores, collected during RIKEAU 2002 cruise on board r/v Thalia, on the shelf of the Bay of Biscay

Mesoscale dynamics in the Mediterranean Sea have been investigated for years and anticyclonic eddies are regularly observed features in the Algerian Basin. In early spring 2016, a field experiment during the ProtevsMed 2016 cruise thoroughly investigated this specific eddy, when it was located near the North Balearic Front, taking high-resolution (Seasoar) hydrological transects, several CTD casts and LADCP measurements. In addition, four drifting buoys were released in the eddy core. These in situ measurements revealed that the vertical structure of this anticyclone was made of two water lenses of very different origins (Atlantic Water above and Western Intermediate Water below) spinning together. In the vicinity of the North Balearic Front, which may act as a dynamical barrier for structures, the eddy interacted with a subsurface anticyclonic eddy made of modal water, which fostered cross-front exchanges generating filaments by stirring. The high-resolution sampling revealed fine scales structures both adjacent to the eddy and within its core. The eddy has been targeted from 21 March to 1 April 2016 taking advantage of a meteorological window. It has been sampled with:  - a towed undulating vehicle, the SeaSoar designed and built by Chelsea Instruments; it gets mounted on its sides two Sea-bird SBE-9 (SBE 3 temperature and SBE 4 conductivity sensors)  and a Wetlabs Fluorometer of type ChloroA WetStar  - CTD casts performed with a Sea-bird SBE-9 (SBE 3 temperature and SBE 4 conductivity sensor) and an RDI 150 kHz current profiler mounted in a general oceanics 12-place rosette, with12l Niskin bottles  - drifters with holey-sock positioned at 50 m deep below the expected Ekman layer thickness (remaining in the eddy until mid May).