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.

This dataset contains the pictures used for morphometric measurements, as well as the elemental compositon and production rates data, of planktonic Rhizaria. Specimens were collected in the bay of Villefranche-sur-Mer in May 2019 and during the P2107 cruise in the California Current in July-August 2021. Analyses of the data can be found at https://github.com/MnnLgt/Elemental_composition_Rhizaria.

The ESA Sea State Climate Change Initiative (CCI) project has produced global daily merged multi-sensor time-series of along-track satellite altimeter significant wave height data (referred to as Level 3 (L3) data) with a particular focus for use in climate studies. This dataset contains the Version 3 Remote Sensing Significant Wave Height product, which provides along-track data at approximately 6 km spatial resolution. It has been generated from upstream Sea State CCI L2P products, edited and merged into daily products, retaining only valid and good quality measurements from all altimeters over one day, with simplified content (only a few key parameters). This is close to what is delivered in Near-Real Time by the CMEMS (Copernicus - Marine Environment Monitoring Service) project. It covers the date range from 2002-2021. The altimeter data used in the Sea State CCI dataset v3 come from multiple satellite missions (Envisat, CryoSat-2, Jason-1, Jason-2, Jason-3, SARAL, Sentinel-3A), therefore spanning over a shorter time range than version 1.1. Unlike version 1.1, this version 3 involved a complete and consistent retracking of all the included altimeters. Many altimeters are bi-frequency (Ku-C or Ku-S) and only measurements in Ku band were used, for consistency reasons, being available on each altimeter but SARAL (Ka band).

The Programme Ocean Multidisciplinaire Meso Echelle (POMME) was designed to describe and quantify the role of mesoscale processes in the subduction of mode waters in the Northeast Atlantic. Intensive situ measurements were maintained during 1 year (September 2000 - October 2001), over a 8 degrees square area centered on 18 degrees W, 42 degrees N. In order to synthesized the in-situ physical observations, and merge them with satellite altimetry and surface fluxes datasets, a simplified Kalman filter has been designed. Daily fields of temperature, salinity, and stream function were produced on a regular grid over a full seasonal cycle. We propose here the gridded fields (KA_ files) and the in-situ datasets used by the analysis (Data_ files).

The ClimateFish database collates abundance data of 15 fish species proposed as candidate indicators of climate change in the Mediterranean Sea. An initial group of eight Mediterranean indigenous species (Epinephelus marginatus, Thalassoma pavo, Sparisoma cretense, Coris julis, Sarpa salpa, Serranus scriba, Serranus cabrilla and Caranx crysos) with wide distribution, responsiveness to temperature conditions and easy identification were selected by a network of Mediterranean scientists joined under the CIESM programme ‘Tropical Signals’ (https://www.ciesm.org/marine/programs/tropicalization.htm; Azzurro et al. 2010). Soon after, and thanks to the discussion with other expert groups and projects, C. crysos was no longer considered, and Lessepsian fishes (Red Sea species entering the Mediterranean through the Suez Canal) were included, namely: Fistularia commersonii, Siganus luridus, Siganus rivulatus, Pterois miles, Stephanolopis diaspros, Parupeneus forskali, Pempheris rhomboidea and Torquigener flavimaculosus. Considering the trend of increase of these species in the Mediterranean Sea (Golani et al. 2021) and their projected distribution according to climate change scenarios (D’Amen and Azzurro, 2020), more data on these tropical invaders are expected to come in the future implementation of the study. Data were collected according to a simplified visual census methodology (Garrabou et al. 2019) along standard transects of five minutes performed at a constant speed of 10m/min, corresponding approximately to an area of 50x5m. Four different depth layers were surveyed:  0-3m, 5-10 m, 11-20 m, 21-30 m. So far, the ClimateFish database includes fish counts collected along 3142 transects carried out in seven Mediterranean countries between 2009 and 2021, for a total number of 101'771 observed individuals belonging to the 15 fish species. Data were collected by a large team of researchers which joined in a common monitoring strategy supported by different international projects, which are acknowledged below. This database, when associated with climate data, offers new opportunities to investigate spatio-temporal effects of climate change in the Mediterranean Sea and test the effectiveness of each species as a possible climate change indicator.   Contacts: ernesto.azzurro(at)cnr.it   References: Azzurro E., Maynou F., Moschella P. (2010). A simplified visual census methodology to detect variability trends of coastal mediterranean fishes under climate change scenarios. Rapp. Comm. int. Mer Médit., 39. D’Amen, M. and Azzurro, E. (2020). Lessepsian fish invasion in Mediterranean marine protected areas: a risk assessment under climate change scenarios. ICES Journal of Marine Science, 77(1), pp.388-397. Garrabou, J., Bensoussan, N., Azzurro, E. (2019). Monitoring climate-related responses in Mediterranean marine protected areas and beyond: five standard protocols. Golani D.,  Azzurro E.,  Dulčić J.,  Massutí E., Orsi-Relini L.  (2021).  Atlas of Exotic Fishes in the Mediterranean Sea.  2nd edition  [F. Briand, Ed.]  365 pages.  CIESM Publishers, Paris, Monaco. ISBN number  978-92-990003-5-9   

In order to better characterize the genetic diversity of Cetaceans and especially the common Dolphin from the Bay of Biscay, sequences from the mitochondrial Cytochrome B region were obtained from water samples acquired close to groups of dolphins.

The French Atlantic coast hosts numerous macrotidal and turbid estuaries that flow into the Bay of Biscay that are natural corridors for migratory fishes. The two best known are those of the Gironde and the Loire. However, there are also a dozen estuaries set geographically among them, of a smaller scale. The physico-chemical quality of estuarine waters is a necessary support element for biological life and determines the distribution of species, on which many ecosystem services (e.g. professional or recreational fishing) depend. With rising temperatures and water levels, declining precipitation and population growth projected for the New Aquitaine region by 2030, the question of how the quality and ecological status of estuarine waters will evolve becomes increasingly critical. The MAGEST (Mesures Automatisées pour l’observation et la Gestion des ESTuaires nord aquitains) high-frequency monitoring of key physico-chemical parameters was first developed in the Gironde estuary in 2004 ; the Seudre and Charente estuaries were instrumented late 2020. First based on real-time automated systems, MAGEST is now equipped by autonomous multiparameter sensors. Depending of the stations, an optode is also deployed to secure dissolved oxygen measurement. By the end of 2020, MAGEST had 12 instrumented sites. Portets is a measuring station located in the upper Gironde estuary (Garonne subestuary, about 20 km upstream of the Bordeaux metropolis.

In order to better characterize the genetic diversity of Cetaceans and especially the common Dolphin from the Bay of Biscay, sequences from the variable mitochondrial control region were obtained from water samples acquired close to groups of dolphins.

We genotyped 1680 thornback ray Raja clavata sampled in the Bay of Biscay using a DNA chip described in Le Cam et al. (2019). After quality control 4604 SNPs were retained for identifying potential sex-linked SNPs using three methods: i) identification of excess of heterozygotes in one sex, ii) FST outlier analysis between the two sexes and iii) neuronal net modelling. Genotype coding: 0 homozygous for major allele, 1 heterozygous, 2 homozygous for minor allele. Flanking DNA sequences of SNPs identified with methods i) and ii) are also provided.  

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).