The NourDem project aims to carry out annual trawling cruises in the three estuaries of the Seine, the Loire and the Gironde.

Like all EU Member States, France is obliged to collect and manage the data necessary to conduct the Common Fisheries Policy to assess the abundance and distribution of stocks. A "national multi-annual basic data collection programme" has therefore been set up in which scientific campaigns such as IBTS are integrated. This campaign is carried out in coordination with most of the countries bordering the North Sea, in the framework of the European Fisheries Data Collection Programme (DC-MAP). The research carried out over the last few decades has led to a shift away from fisheries issues stricto sensu (monospecific and geographically limited studies) towards a more integrated vision of the various components of marine ecosystems. This openness results from a desire to better understand the dynamics of exploited marine resources in order to improve diagnoses and management recommendations. The acquisition of data from these compartments at different stations makes it possible to establish a map of biotic and abiotic environmental parameters in the Channel and North Sea during the winter period, a period that is usually little studied, but which is crucial.

The French national network (REMI) includes a regular monitoring system and a warning system: - The regular monitoring system checks that the level of microbiological contamination in each production area remains within the limits set by the classification defined in the prefectural decree and tests unusual occurrences of contamination. - The warning system is triggered when results of the monotoring programme exceed or are at risk of exceeding the norms defining the quality classes and thresholds, or in case of contamination risk (pollution spillage, storms, etc.), or even in the case of a suspected or confirmed epidemic in shellfish.

As part of the implementation of the monitoring programme of the Marine Strategy Framework Directive (MSFD), the monitoring of demersal fish and cephalopods in coastal soft environments was deemed a priority. Annual observation campaigns of coastal nurseries on soft bottoms were carried out by the Laboratoire Halieutique Méditerranée of the Ifremer station in Sète. The objectives of these campaigns are 1. To evaluate the density, biomass and distribution of fish and cephalopods by trawling, in particular benthic and demersal juveniles (red mullet, gurnard). To do this, around one hundred standardised trawl surveys were carried out over the entire coastal strip of the Gulf of Lion situated between 5m and 40m depth. 2. To systematically measure the size of the individuals collected in order to characterise the importance of the nursery function in the areas observed and to better understand the population dynamics of local species. 3. To gain a better understanding of the coastal zone ecosystem by systematically identifying all the species encountered (including benthic and pelagic invertebrates other than fish and cephalopods), the macro-waste observed and by characterising their hydrological habitats (CTD, oxygen, fluorescence, pH, turbidity, etc.).

The COMOR cruises, which took place on the Thalia, aim to assess the abundance of the scallop stock (and if necessary to determine the presence of toxic algae) in the Seine Bay.

EVRWE is a multiannual survey with the following objectives: - Building up time series of abundance indices for the main dermersal and benthic species in the Celtic Sea and the Bay of Biscay. - Measuring inter-annual changes in their recruitment. - Mapping the spatial distributions of the species and their inter-annual variations, as well as looking for the origin of this variability (biotic and/or abiotic parameters, fisheries impact). - In the framework of the 'Bay of Biscay' challenge, the data collected are vital for understanding changes in faunal communities.

The annual PELMED (PELagiques MEDiterranée) fisheries resource assessment campaign is carried out by the Laboratoire Halieutique Méditerranée of the Ifremer station in Sète. The objectives of these cruises are : 1. Evaluate the biomass of small pelagic fish (anchovies, sardines) by direct method. For this, the campaign must alternate between acoustic prospecting and identification trawling. An acoustic signal is sent from a sounder fixed under the vessel and each time it encounters the bottom or schools of fish, it is reflected and retransmitted to the sounder. In this way, the shape and intensity of these echoes that materialize the schools of fish can be observed continuously. Species identification trawls are carried out in order to define the proportion of species present in the echoes detected. 2. Collecting as many biological parameters as possible on the target species of small pelagics (anchovies, sardines, sprats) to better understand the population dynamics of these species. For this purpose, morphometric measurements, as well as the determination of the sex and maturity stage of the fish are carried out. Finally, otoliths are taken in order to determine the age of the fish. These biological parameters are very important to complete the biomass assessment and have a better understanding of the processes underlying the variability of these populations. This allows for example to determine the age structure or size structure of the populations, to have an idea of their energy reserves, etc. 3. To better understand the pelagic ecosystem as a whole, from plankton to top predators. The primary goal of the PELMED cruise is to evaluate small pelagic stocks, but it also aims to accumulate as much data as possible on the different compartments of the pelagic ecosystem, from physical parameters (temperature, salinity) to top predators (marine mammals, birds), through the different lower trophic levels (phyto- and zooplankton, small pelagic fish). Thus, after each trawling, a hydrological station is carried out with the measurement of temperature and salinity along the water column via a CTD, water and phytoplankton samples with a Niskin bottle and zooplankton samples using a vertical line of WP2. Finally, throughout the campaign we carry out the observation and counting of birds and marine mammals. In addition to the understanding of the ecosystem, this should provide a number of indicators necessary for monitoring the marine environment under the MSFD (Marine Framework Directive).

CGFS cruise aims to collect basic data to estimate the status of fisheries resources, by direct assessment of stock abundance and distribution, along with biological sampling of commercial catches. The CGFS campaign is carried out within the framework of this programme in the European project Contractualisation of Basic Fishery Data Collection (DCF). The abundance indices collected during this campaign are used by the ICES international working group "Demersal fisheries of the North Sea, Eastern Channel and Skagerrak" and complement the data from the English "Beam Trawl Survey" for the "Flatfish" working group.