The Ifremer experimental site in Argenton, within LEMAR, is a tool dedicated to experimentation on marine bivalves under controlled conditions. It allows the study of the physiological response of these animals, under the effect of biotic and abiotic factors in the environment, including various disruptors (e.g. pathogens, toxic algae, micro- and nanoplastics, pharmaceutical residues).
This experimental tool makes it possible to work in a "controlled environment" in vitro/in vivo and thus simplify the complexity of the natural environment ("free environment"). Various factors, such as seawater temperature, pH, salinity, trophic resource quality and quantity, as well as the zoo-health environment of the bivalves studied, can be controlled. With this tool, teams can test hypotheses established in the natural environment and provide observations useful for modeling in silico.
Among the experimental rooms of the site, some are dedicated to the study of early stages, juveniles or adults, in breeding structures of various shapes and volumes, adapted to each life stage. These rooms are equipped with automatic measuring machines that enable, among other things, the feeding of animals (Coulter counter) and their behaviour (larval observation chamber) to be estimated. They can be adapted according to the hypotheses to be tested, the biological scale studied (individual or population level) and the need to replicate experimental conditions. All the rooms are fed in open flow by sea water pumped into a 10,000m3 fishpond whose sea water, under oceanic influence, is renewed according to the tides. After passing through the experimental rooms, the water is collected in an effluent treatment system. Daily production of microalgae, up to 1200 L/day, is carried out in a dedicated room to feed the animals. Several species of microalgae can thus be produced according to needs. Specific experimental rooms (e.g. quarantine of animals, metrology of measuring devices) as well as work areas to prepare certain so-called field experiments (e.g. monitoring of larval recruitment in natural environment, natural method of infection in situ) also exist on the Argenton Ifremer site. Some experiments conducted in the tool have indeed an extension in a natural environment, on a workshop site in Rade de Brest in an oyster farming area.
The hollow oyster is currently the most studied biological model on the site. The life cycle of this species is well controlled. A disease-free biological reference material, the Ifremer Standardised Naissains (NSI), produced on site according to standard and controlled protocols, is used for several research projects using the hollow oyster as a biological model. However, other ecologically and economically important species (flat oyster, scallop shell, clam, mussel) can also be studied in Argenton's Ifremer experimental tool.
The research carried out on the site is funded by the ANR, the Direction des Pêches Maritimes et de l'Aquaculture, the Fondation pour la Recherche sur la Biodiversité at national level, but also at European level (FP7, H2020, Interreg), and at regional level (Labex, Brittany Region) or by research supervisors.