Recent advances in coastal lagoons ecology: evolving old ideas and assumptions.

1 - Coastal lagoons are among the most productive ecosystems in the world. Their particular features, which include shallowness, relative isolation and protection from the sea, together with the presence of boundaries with strong physical and ecological gradients, make them especially interesting for human use. They provide goods and services for humans by supporting important fisheries, and intensive and extensive aquaculture exploitations. At the same time, they are suitable for other activities such as nautical sports, swimming or health care.2 - However, their close relation with terrestrial ecosystem boundaries and the pressures derived from human activities, make these environments especially vulnerable to human impact and terrestrial and freshwater inputs. Because of their importance for human interests and their vulnerability, there is increasing social concern on the necessity for protecting and managing coastal lagoons.3 - To manage a system we need to understand how it works and this implies that we need to know the components of the system, their links, the processes involved in their functioning and the causeeffect relationships between human activities and the alteration of ecological processes, as a prior step to building bio-economic models and decision support tools.4 - Our knowledge and related conceptual bases of the ecological processes at work in coastal lagoons developed between the 1960s and 1990s, a period of intense activity in the study of these transitional ecosystems, including estuaries and brackish waters, in general, of the Mediterranean and Europe. However, after an apparent decline in concern and scientific production on these ecosystems, recent years have seen fresh interest in their study, both in Europe and the rest of the world, with the number of publications appearing in high impact journals increasing significantly. Knowledge and assumptions concerning coastal lagoon processes and functioning have evolved very quickly during these last decades.5 - In this contribution, we analyze recent developments and findings on lagoon ecology concepts and the consequences for lagoon management, as well as the importance of constituting lagoon research networks and common data bases to boost future developments and to improve our management and decision making capabilities