Multi-omics effect of contaminants exposure during embryogenesis on metamorphosis of blue mussel Mytilus edulis submitted to maritime traffic noise

Anthropogenic underwater noise is now considered one of the ‘emerging threats and ongoing challenges to biodiversity conservation’. Physiological changes have been observed in sessile invertebrates such as bivalves. Bivalve mollusks are of particular interest because of their sensitivity to sound, their inability to move away from the sound source, and their considerable economic and social importance. A growing number of studies have examined the acoustic effects of shipping on invertebrates, but few have considered the interaction of multiple stressors to approximate a real ecological context. Noise can interact with chemical contaminants to disrupt the behavior of organisms and have complex effects. Recent studies on invertebrates have shown that noise amplifies the harmful effects of heavy metals such as cadmium. In a harbor environment in the Gulf of St. Lawrence, the stress response of post-larval mussels, Mytilus edulis , was studied using an ecophysiological-ecotoxicological approach. To achieve this, competent pediveliger larvae, previously exposed to a cocktail of pollutants simulating the maritime environment of a port until the end of embryogenesis, were exposed to acoustic perturbations during metamorphosis. The aim was to assess the response of competent larvae ( i.e. during metamorphosis) following early life chemical contamination and interaction with noise exposure representative of maritime traffic. This study shows that the effects of early chemical pollution during embryogenesis have a greater impact on larvae than noise exposure later during metamorphosis. In fact, latent effects of early chemical exposure persist, with consequences for size at metamorphosis, energy and oxidative metabolism, and lipid profile of post-larvae.