Réponses écophysiologiques des huîtres aux stress environnementaux multiples : une approche intégrée entre observations à long terme et expérimentations contrôlées

This Habilitation à Diriger des Recherches (HDR) falls within the field of marine bivalve ecophysiology, and more specifically the Pacific oyster Crassostrea gigas. The objective of this study is to comprehend the manner in which these organisms react to the variability and manifold pressures of a rapidly evolving coastal environment. The present study combines long-term observations and controlled experiments in order to explore the ecophysiological responses of oysters at different scales, ranging from the molecular level to the population level. In situ monitoring conducted as part of the national ECOSCOPA network has facilitated the characterisation of environmental regimes along the French coastline and the identification of the primary determinants of mortality according to age, origin, and hydroclimatic contexts. Experiments conducted under controlled conditions have enabled the isolation of the effects of various stresses – thermal, trophic, acidification, and pathogenic – and the analysis of their interactions on physiology, growth, and survival. These complementary approaches have resulted in a more profound comprehension of the mechanisms of vulnerability and resilience in oysters, and have led to the development of forecasting and management tools for the oyster farming industry. Consequently, they have the potential to engender a paradigm shift towards more sustainable practices, including co-culture and integrated multitrophic aquaculture.