Meagre, Argyrosomus regius, is an important resource for local fishing communities along the Atlantic coast, from France to Mauritania. Growing concerns that it might be under overexploitation threat are consubstantiated by its aggregating spawning behaviour, possible population fragmentation, and fast historical collapses of similarly large-bodied sciaenids. This project aims at providing a clear answer to this concern: do meagre Atlantic populations depend on very few sites where they aggregate to spawn? We will use a multidisciplinary approach combining telemetry, genomics and modelling to map the spatial ecology and the (spawning) Essential Fish Habitat, and to explore questions of natal phylopatry and/or adaptiveness, connectivity between populations, and potential impacts of climate change on their capacity to adapt to spawning habitat change. This information will be key to assess current and future threats, and should supply solid management guidelines for iconic species.