Effect of chemical pollution representative of an industrial port on the embryonic success of the blue mussel, <i>Mytilus edulis</i> : a metabolomic approach

With the growing demand for international maritime trade, there is an urgent need to improve our knowledge of the impact of shipping on marine organisms to develop effective mitigation strategies. Bivalves are important organisms in intertidal ecosystems where maritime harbors are situated. In this work, we evaluated the response of mussel larvae exposed to chemical contaminants associated with maritime traffic. We focused on embryogenesis because the initial ontogenic stages are particularly susceptible to stressful events that are crucial for maintaining community structure. Thus, embryos of the blue mussel, Mytilus edulis Linnaeus, 1758, from two spawning events following natural gonad maturation, were exposed to a cocktail of contaminants (copper, mercury, lead, and hydrocarbons) representative of a port environment until the end of embryogenesis. Our results show a different metabolomic response of D-larvae to contamination depending on the embryogenic success. Contaminated larvae had greater energy requirements and appeared to successfully employ a variety of mechanisms involving antioxidant biosynthesis and energy metabolism restructuring to mitigate toxic effects on cells and developing tissues. This work demonstrates the vulnerability of mussel larvae to an environment with high maritime traffic, even though exposure to contaminants did not ultimately affect the success of embryogenesis.