The EU FP5 funded COLASU project on the Sustainability of Mediterranean coastal lagoon ecosystems under semi-arid climate, was launched in Strasbourg during 25 to 27 July 2002. The scientific coordination, led by IRMCo, of the project brings together research teams from France, Portugal, Spain, Tunisia and Morocco. The lagoon ecosystem of El Meleh in Tunisia and the much larger Nador lagoon in Morocco provide the 2 case studies for the project.