CRUScH

CRUStaceans facing CHemical contaminations: adaptability of riverine and marine populations, and vulnerability to environmental change

2026 - 2030

The CRUScH project addresses a key question in ecotoxicology within the context of the aquatic biodiversity crisis: the long-term effects of population exposure to contaminated environments. Current ecological risk assessment (ERA) methods rely on toxicity data from laboratory strains, overlooking genetic and ecological variations within species. This approach neglects the eco-evolutionary effects of contaminants and the indirect consequences for populations exposed to environmental changes.
CRUScH adopts a large-scale comparative approach to study the adaptability of crustaceans (freshwater gammarids and coastal palaemonids) in various contamination contexts, integrating their genetic diversity. Two hypotheses will be tested: (1) multigenerational exposure to pollutants triggers local eco-evolutionary processes (phenotypic plasticity, selection), creating greater sensitivity differences between populations than between species or phylogenetic lineages; (2) prolonged exposure to contaminants increases population vulnerability to other environmental stressors.
CRUScH aims to achieve four objectives: (1) establish phylogenetic relationships and sensitivity variability to four contaminants in 100 French rivers and 30 Franco-Spanish coastal stations, whether exposed to contamination or not; (2) characterize the plastic nature of tolerance at individual and intergenerational scales; (3) assess the effects of exposure on population genetic diversity; (4) test the vulnerability of contaminant-tolerant populations to other stressors (parasitism, heat waves, hypoxia, ocean acidification).
By combining expertise in ecotoxicology and molecular ecology, the project will enhance understanding of eco-evolutionary processes in the current context of persistent environmental contamination and provide insights for improving current ERA practices.