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

The SOMLIT-Antioche observation station, located at 5 nautical miles from Chef de Baie harbor (La Rochelle) is part of the French monitoring network SOMLIT (https://www.somlit.fr/), accredited by the INSU-CNRS as a national Earth Science Observatory (Service National d’Observation : SNO), which comprises 12 observation stations distributed throughout France in coastal locations. It aims to detect long-term changes  of these ecosystems under both natural and anthropogenic forcings. SOMLIT is part of the national research infrastructure for coastal ocean observation ILICO (https://www.ir-ilico.fr/?PagePrincipale&lang=en). The SOMLIT-Antioche station (46.0842 °N, 1.30833 °W) is located in the north-eastern part of the Bay of Biscay, halfway between the islands of Ré and Oléron, at the centre of what is commonly known as the Pertuis Charentais area, which correspond to a semi-enclosed shallow basin and includes four islands (Ré, Oléron, Aix and Madame) and three Pertuis (i.e., detroit) (Breton, Antioche and Maumusson). This 40m-deep site, with muddy to sandy marine bottoms, is submitted to a macro-tidal regime and is largely open to the prevailing westerly swells. It remains under a dominant oceanic/neritic influence, even though its winter/spring hydrological context is influenced by the diluted plumes of the Charente, Gironde and Loire rivers, but not by those of too small estuaries (Lay, Seudre and Sèvre Niortaise). SOMLIT-Antioche hydrological monitoring has been carried out by the LIENSs/OASU laboratory on a fortnightly basis since June 2011. Surface water samples are collected  at high-tide during intermediate tides (70 ± 10 in SHOM units) on board the research  vessel ‘L’Estran’ owned by La Rochelle University. Samples are analyzed for more than 16 core parameters: temperature, salinity, dissolved oxygen, pH, ammonia, nitrates, nitrites, phosphates, silicates, suspended matter, particulate organic carbone, particulate organic nitrogen, chlorophyll, delta15N, delta13C; pico- and nano- plankton. Measurements are carried out in accordance with the ISO/IEC 17025:2017 standard. Simultaneous monitoring of the micro-phytoplankton community (since 2013, SNO PHYTOBS: https://www.phytobs.fr/en) and monitoring of prokaryotic communities (Bacteria and Archaea) are also carried out on a monthly basis. Since 2019, seasonal observations of benthic invertebrate communities (SNO BenthObs : https://www.benthobs.fr/) have also been carried out. This monitoring is complementary to that carried out at hydrological stations in the pre-existing REPHY and DCE networks, some of which are located near marine farming areas (oyster and mussel farms).

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.

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 Charente estuary. Measurements are organized into .csv files, with one file per year. Data is collected using a SAMBAT multiparameter probe, which records the following parameters: - Temperature (-5 to 35 °C) - Conductivity (0 to 10 mS/cm) - Pressure (0 to 10 m) - Turbidity (0 to 300 NTU) - Dissolved Oxygen (0 to 20 mg/L & 0 to 200 %) - Fluorescence (0 to 50 µg/l) - PH (0/14)

EVHOE (« Evaluation Halieutique de l’Ouest Européen ») surveys provide observational data on bentho-demersal communities on the continental shelves of the Bay of Biscay and the Celtic Sea for more than 30 years. The surveys operate a standardized bottom trawling gear and are conducted from 15 to 600 m depth, usually in the fourth quarter of the year, starting at the end of October. The main objectives are the monitoring of 22 commercial stocks of fish species and 10 cephalopods from the North-East Atlantic. The dataset also provide a description of regional diversity, including 250 taxa of fish, 45 taxa of cephalopods and others “commercial” invertebrates and, from 2008, more than 350 other taxa of benthic invertebrates. The acquisition of this dataset, organised by IFREMER, is steered by the IBTS working group organised within the framework of ICES. It is being funded by the European DCMAP programme, in coordination with the French Directorate-General for Maritime Affairs, Fisheries and Aquaculture (DGAMPA). This dataset is of great interest for the long-term monitoring of the continental shelves of the Bay of Biscay and the Celtic Sea. Moreover, on a larger scale, by being integrated into a European network of bottom trawl surveys, these data play an essential role in studying the evolution of ecosystems from continental shelves to the scale of the eastern North Atlantic. From April 2025, the proposed data have been updated in the latest standard format recognised by IFREMER (‘ELFIC’ format). The 5 data tables are compiled in a .zip file which also contains a document detailing the content of each table and their respective data fields.

For the 21 years of the study, an examination of trends in chlorophyll concentration revealed a general decline throughout the Gulf over the production period. These trends, extracted from dynamic linear model, also allowed this decline to be quantified. Expressed as a percentage, a large part of the area below the 50 m bathymetric line showed a decrease of at least 10% over the period, corresponding to a value of at least 0.1 µg.l-1. However, the spatial distribution reveals some more local phenomena. In southern Brittany, from Quimper to Vannes, a particular feature appears, with an upward trend over several kilometres along the coast, followed by a pronounced gradient along the coast. This gradient includes a zone where a continuous monotonic increasing trend is observed, then a zone where the trend becomes not significant and finally, about 15 km from the coast, a new zone where a significant continuous monotonic decreasing trend is observed. The increase in chlorophyll a concentration in the very coastal part is greater than 0.1 µg.l-1 over the period. Another peculiarity concerns the central part, located at the edge of the plateau at Cap Ferrat and Pente Aquitaine, where an increase in chlorophyll a was observed, but the variations remained small, being less than 0.1 µg.l-1. About a hundred kilometres south-west of Saint Nazaire, an area of about 40 by 50 km shows a decrease in chlorophyll a of more than 20%, quantified as more than 0.1 µg.l-1 over the period.

Global Fishing Watch is working across the globe to provide governments and authorities with actionable reports and capacity building to help strengthen fisheries monitoring and compliance. Our global team of experts produce analyses to inform monitoring, control and surveillance of fisheries in five key areas: - Illegal, unreported and unregulated fishing - Transshipment - Port controls - Marine protected areas - Operation support Collaboration and information sharing are integral to achieving well-managed fisheries. By working with stakeholders and making analyses available to national, regional and intergovernmental partners, Global Fishing Watch is enabling fisheries agencies to make more informed and cost-efficient decisions. Topics: - Commercial fishing, Global Fishing Watch is harnessing innovative technology to turn transparent data into actionable information and drive tangible change in the way that fisheries are governed. - Transshipment, Through publicly sharing map visualisations and creating data and analysis tools, we seek to inform management and policy efforts and provide a more complete picture of transshipment at sea. - Marine protected areas, Global Fishing Watch is harnessing the data and technology revolution to support the effective design, management and monitoring of marine protected areas.

The ORHAGO campaigns (Observation of the benthic aquatic resources of the Golfe de Gascogne) are designed to collect data on the composition, distribution and change in relative abundance of benthic fish fauna on the continental shelf (depth <100m) in November to December on a yearly basis. The ORHAGO survey was initiated in 2007 with the objective of developing a fishery-independent abundance index for flatfish species, with a particular focus on the common sole (Solea solea) of the Bay of Biscay. In accordance with the ICES-agreed gear for flatfish abundance surveys, ORHAGO employs a 4-meter-beam trawl with a chain mat, 50-millimeter mesh in the net, and 40-millimeter mesh in the cod-end. The sampling plan was designed to ensure full coverage of the common sole habitat in the Bay of Biscay during a period (November-December) for which fish behavior and distribution was suitable for obtaining an unbiased abundance index (young fish move offshore when coastal waters become colder and before the concentrations of the spawning season). The sampling design is a systematic sampling with 49 reference stations. The sampling design was validated in 2013 by the ICES Working Group on Beam Trawl Surveys (WGBEAM). Since 2013, the ORHAGO survey has been used to assess the status of the Bay of Biscay common sole stock (WGBIE, Working Group for the Bay of Biscay and the Iberian Waters Ecoregion).

The willingness to pay (WTP) of people to protect animal populations can be used as a tool for these populations’ conservation. The WTP reflects the non-use value of animals, which can be significant for charismatic species. This value can be used as an economic criterion for decision-makers in order to recommend protective measures. The definition of the WTP to protect a species is challenging, as valuation methods are time-consuming and expensive. To overcome these limitations, we built a benefit transfer function based on 112 valuation studies and apply it to 440 Mediterranean marine species. We extracted these species from the IUCN database and retrieved some required parameters from, amongst others, the FishBase database. Marine mammals appear to have the highest WTP value followed in order by sea turtles, sharks and rays, and ray-finned fishes. Commercial fish species appear to have the highest values amongst the fish class.

This folder contains two examples of PAGURE datasets, corresponding to three surveys: -CGFS conducted in 2018 in the English Channel (Northeast Atlantic) -EPIBENGOL conducted in 2019 in the Gulf of Lion (Western Mediterranean) -EVHOE conducted in 2020 in the Bay of Biscay and Celtic Shelf (Northeast Atlantic) Files include metadata for the sampling stations, annotation files. A readme tex file contains the links to the voyage metadata This folder is aimed at providing an example of documented underwater imagery dataset. These data are part of the data exchange conducted in the QuatreA collaboration between the French Research Institute for the Exploitation of the Sea (Ifremer), the Commonwealth Scientific and Industrial Research Organisation (CSIRO), and the University of Tasmania (UTAS).