The data concerns the structure and morphometry of the seagrasses Zostera marina and Zostera noltei, the diversity of the associated epifauna and the benthic fluxes of oxygen, carbon and nutrients. The dataset includes 103 sampling events divided among four sites and spread across three distinct marine biogeographic regions (i.e. the English Channel, Bay of Biscay and Western Mediterranean), and up to five seasons, depending on the site. The sampling scale allows inter-site and intra-habitat comparisons . Environmental conditions are also described at the site scale. As the most comprehensive and broadscale French dataset on seagrass structure and functioning  to date, it is useful for both data analysis and management actions.

An observation network was initiated in 2021 in the framework of the CocoriCO2 project to monitore carbonate parameters along the French coastal systems. Six sites were selected along the French Atlantic and Mediterranean coastlines based on their importance in terms of shellfish production and the presence of high- and low-frequency monitoring activities. At each site, autonomous pH sensors were deployed both inside and outside shellfish production areas, next to high-frequency CTD (conductivity-temperature-depth) probes operated through two operating monitoring networks (SNO COAST-HF and Ifremer ECOSCOPA). pH sensors were set to an acquisition rate of 15 min and discrete seawater samples were collected biweekly in order to control the quality of pH data (laboratory spectrophotometric measurements) as well as to measure total alkalinity and dissolved inorganic carbon concentrations for full characterization of the carbonate system. While this network has been up and running for more than two years, the acquired dataset has already revealed important differences in terms of pH variations between monitored sites related to the influence of diverse processes (freshwater inputs, tides, temperature, biological processes).    

Données de Metabarcoding de phytoplancton marin (18s), taxon bactérien et archés (16s) pour la caractérisation de la diversité marine à partir d'ADN extraits sur filtres (eau de mer ou d'étangs filtrés sur 0,22um ou 3um) selon conditions variables de lumière et de température