ICARE

All over the world, and on different scales, it has been shown that major climatic variations are already being felt. In the “Normandie and Pays de la Loire” regions, the IPCC reports are unequivocal and speak of the reality of changes and an increase in climatic hazards. Even if the consequences are visible and others are in prospect, the first observation is that these changes are having an impact on the region, its ecosystems and its agricultural and economic players. A second observation is that knowledge of the risks associated with these climate variations is very inadequate in relation to the challenges facing society and sustainable development. The ICARE project proposes to improve this knowledge by looking at the impact of climate change on water quality and biodiversity in the Sarthe and Mayenne rivers, and the Loire River in the region. At the level of these ecosystems, we will be looking at the micro-biodiversity governing the first links in the trophic chain and the functioning of the rivers. This will be done by taking water samples from the three aquatic systems and identifying microorganisms using microscopy and molecular biology techniques. This will be coupled with monitoring of parameters such as water temperature and height, the presence or absence of certain nutrients, etc. At the same time, we will understand how products linked to agriculture can move around in these ecosystems, in particular via adsorption on the plastics that we will collect and analyse throughout the year. In this way, we will be able to visualise changes in the composition of phytoplankton and relate these variations to the year's climate data and the presence of plastics and agricultural pollutants. In the laboratory, we will be able to expose aquatic organisms (microalgae, bivalves, etc.) as well as human cells to the various pollutants identified on plastics. The organisms or the human cells, in in vitro culture, will be exposed to the same types and doses of pollutants found in the Sarthe, Mayenne and Loire rivers, and their response will be monitored at various levels: growth and cell proliferation, defence genes expression, etc. The aim is to model responses on environmental and human health. Our multidisciplinary group has the diverse and complementary skills needed to successfully complete this project. The scientists in the consortium have expertise in both physical-chemistry, to identify pollutants, and biology, to identify micro-organisms, as well as genetics, molecular biology and cell culture. The team will be supported by an engineer specialising in statistics, particularly in relation to ecology. Once again, this will enable us to create predictive models on the evolution of the health of aquatic systems and to propose improvements. The sampling campaigns will be carried out throughout 2024. We hope to provide answers to the many questions that are being asked in the region and to provide new data that will be as useful to the scientific community as to the socio-economic players in our two regions, and in particular the Normandy-Maine Regional Park.