The Estuarine & Coastal Sciences Association (ECSA) symposium on Estuarine and Lagoon Ecosystem Trajectories (ELET) organised by CEMAGREF (now IRSTEA), Université de Bordeaux, France, 24–28th October, 2011, was an opportunity to bring together researchers from 13 countries to strengthen the transdisciplinary links between the natural sciences and the social sciences. The selected papers published in this journal after peer-review are proposing methods to highlight the evolution of resources, from population to community, facing anthropogenic impacts or climate change.