ACTNOW at CEPA7 Conference (Brest)

ACTNOW Early Career Scientist Eugénie Dereuder (PhD student from the University of Rostock) participated at the Conférence d’Ecophysiologie Animale (CEPA7) in Brest, France.

Eugénie's research, titled “Histological, biochemical and molecular assessment of the interactive effects of a pharmaceutical (fluoxetine) and hypoxia on the reproduction and metabolism of the blue mussel Mytilus edulis”, investigated the interactive effects of a common pharmaceutical, fluoxetine (FLX), and hypoxia (low oxygen) on the metabolism and reproduction of the blue mussel (Mytilus edulis). Using a multi-level approach (histological, biochemical, and molecular analysis), the study found that increasing FLX impaired gamete density in females, while hypoxia impaired it in males. Although the combined stressors didn't affect energy reserves, hypoxia led to elevated mitochondrial activity, suggesting a compensatory effort. Crucially, the effects of fluoxetine on certain metabolic pathways were suppressed under hypoxia, demonstrating a complex interaction.

This study is highly relevant as it addresses the need to understand multiple anthropogenic impacts—pharmaceutical pollution and dissolved oxygen dynamics—acting simultaneously on marine organisms. The finding that the impact of a pharmaceutical is modulated by varying oxygen conditions is critical, showing that effects observed under laboratory normoxia may not accurately predict outcomes in oxygen-depleted coastal areas. Furthermore, the work advances our knowledge of serotonergic pathways in molluscs and their role in mediating physiological responses to combined stress, providing key data for assessing the fitness and vulnerability of keystone species like Mytilus edulis in a changing ocean.