Understanding the spatial and temporal preferences of toxic phytoplankton species is of paramount importance in managing and predicting harmful events in aquatic ecosystems. In this study we address the realised niche of the species Alexandrium minutum, Pseudo-nitzschia fraudulenta and P. australis. We used them to highlight distribution patterns at different scales and determine possible drivers. To achieve this, we have developed original procedures coupling niche theory and habitat suitability modelling using abundance data in four consecutive steps: 1) Estimate the realised niche applying kernel functions. 2) Assess differences between the species’ niche as a whole and at the local level. 3) Develop habitat and temporal suitability models using niche overlap procedures. 4) Explore species temporal and spatial distributions to highlight possible drivers. Data used are species abundance and environmental variables collected over 27 years (1988-2014) and include 139 coastal water sampling sites along the French Atlantic coast. Results show that A. minutum and P. australis niches are very different, although both species have preference for warmer months. They both respond to decadal summer NAO but in the opposite way. P. fraudulenta realised niche lies in between the two other species niches. It also prefers warmer months but does not respond to decadal summer NAO. The Brittany peninsula is now classified as an area of prevalence for the three species. The methodology used here will allow to anticipate species distribution in the event of future environmental challenges resulting from climate change scenarios.

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).

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.

REPHYTOX dataset includes long-term time series on phycotoxins in marine bivalve molluscs, since 1987, along the whole French coast. The dataset covers results on lipophilic toxins, PSP toxins, ASP toxins, and palytoxins. REPHYTOX was a full part of the REPHY network until 2015. The whole dataset is available.

The network was initiated by IFREMER from 1993 to 2009 (under the acronym REMORA) to study the rearing performance of the Pacific oyster Crassostrea gigas at a national scale. To do so, the network monitored annually the mortality and growth of standardized batches of 18-month-old oysters. Starting in 1995, the monitoring of the rearing performance of 6-month-old oyster spat was integrated into this network. These sentinel batches were distributed simultaneously each year on 43 sites and were monitored quarterly. These sites were distributed over the main French oyster farming areas and allowed a national coverage of the multiannual evolution of oyster farming performances. Most of the sites were located on the foreshore at comparable levels of immersion. Field studies were carried out by the "Laboratoires Environnement Ressources" (LER) for the sites included in their geographical area of investigation. Following the increase in spat mortality in 2008, the network evolved in 2009 (under the acronym RESCO). From this date, the network selected 13 sites among the 43 sites previously monitored in order to increase the frequency of visits (twice a month) and the number of sentinel batches. More precisely, sentinel batches of oysters corresponding to different origins (wild or hatchery, diploid or triploid) and to two rearing age classes (spat or 18-month-old adults) were selected. The monitoring of environmental variables (temperature, salinity) associated with the 13 sites was also implemented. The actions of the network have thus contributed to disentangle the biotic and abiotic parameters involved in mortality phenomena, taking into account the different compartments (environment / host / infectious agents) likely to interact with the evolution of oyster rearing performance. Finally, since 2015, the network has merged the RESCO and VELYGER networks to adopt the acronym ECOSCOPA. The general objective of this current network is to analyze the causes of spatio-temporal variability of the main life traits (Larval stage - Recruitment - Reproduction - Growth - Survival - Cytogenetic abnormalities) of the cupped oyster in France and to follow their evolution on the long term in the context of climate change. To do this, the network proposes a regular spatio-temporal monitoring of the major proxies of the life cycle of the oyster, organized in three major thematic groups: (1) proxies related to growth, physiological tolerance and survival of experimental sentinel populations over 3 age classes: (2) proxies related to reproduction, larval phase and recruitment of the species throughout its natural range in France, and: (3) proxies related to environmental parameters essential to the species (weather conditions, temperature, salinity, pH, turbidity, chlorophyll a and phytoplankton) at daily or sub-hourly frequencies. Working in a geographical network associating several laboratories, ECOSCOPA provide these monitoring within 8 sites selected among the previous ones to ensure the continuity of the data acquisition. Today, these 8 sites are considered as ecosystems of common interest, contrasted, namely : - The Thau lagoon - The Arcachon basin - The Marennes Oléron basin - The Bourgneuf Bay - The bay of Vilaine - The bay of Brest - The bay of Mont Saint Michel - The bay of Veys The ECOSCOPA network is therefore one of the relevant monitoring tools on a national scale, allowing to objectively measure through different proxies the general state of health of cultivated and wild oyster populations, and this for the different sensitive phases of their life cycle. This network aims at allowing a better evaluation, on the long term, of the biological risks incurred by the sector but also by the ecosystems, in particular under the increasing constraint of climatic and anthropic changes. Figure : Sites monitored by the ECOSCOPA network  

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).

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.

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.  

Bivalves carbon and nitrogen elemental and isotopic ratios (δ13C, δ15N, C and N%, C:N) times series (1981-2021) from 33 sites in France. Bivalve species are the Pacific oyster Crassostrea gigas, and the mussels Mytilus edulis and Mytilus galloprovincialis. This extensive dataset offers a comprehensive view spanning multiple decades and ecosystems, allowing to track how coastal ecosystems and marine species record changing climate, physical-chemical environments and organic matter cycles. This dataset may also be used to study bivalve physiology. Additionally, these data are crucial for establishing isotope baselines for studying food webs. Ultimately, this data set provide valuable information for more effective ecosystem conservation and management strategies in our rapidly changing world.

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