This operation consists in financing structuring scientific equipment (aquatic mesocosms), fitting-out works necessary for their installation as part of the research project CPER FENOMENES – Experimental Aquatic Platform. Aquatic mesocosms are experimental systems for simulating and studying small-scale aquatic ecosystems. They can reproduce natural conditions while controlling various environmental parameters such as temperature, light, nutrient concentration or turbulence. To the control of these natural abiotic conditions can also be added the control of various pollutants (chemical and organic contaminants, pathogens, microplastics...) aiming to reproduce the global changes currently impacting aquatic ecosystems. The work carried out in such devices makes it possible to address the complex interactions that govern aquatic ecosystems, being as close as possible to the natural system, and to assess the direct and indirect effects of human activities on these ecosystems. Mesocosms therefore represent powerful tools for understanding and predicting the effects of anthropogenic stresses (pollutants, global warming, etc.) on the functioning of aquatic ecosystems.