Résumé
Mediterranean coastal lagoons are now recognized as complex ecosystems whose functional richness is due in part to the mosaic of habitats. Phase 2 of the CHAMILA (Cartographie des HAbitats en MIlieu LAgunaire méditerranéen) project consolidates the first available cartographic results by providing new habitat maps (level 6 including biology) for all 36 French Mediterranean lagoons covered by the WFD, and by making these maps more reliable in terms of methods and uncertainties. The results of this project are the subject of (1) this report (context, summary of methods and data, analysis of the distribution of the main habitats on a façade scale), (2) a cartographic atlas on a lagoon scale and (3) a description of the 15 main habitats of French Mediterranean lagoons. The new version of the lagoon habitat typology includes salinity, temperature, substrate type, biological zone, hydrodynamics, trophic richness and biology. Based on updated data for the period 2016-2022, 169 habitats are now described (compared to 224 habitats in the previous version) across all French coastal Mediterranean lagoons, with 1 to 22 different habitats per lagoon. Analysis of these results highlights the uniqueness of lagoon habitats across the entire coastline, with 148 of them present in just one lagoon. Poly-euhaline habitats covered with sparse vegetation and poly-euhaline habitats whose plant cover is dominated by macro-algae appear to be in the majority on the scale of the French Mediterranean coast, in terms of surface area, the number of different habitats and the number of lagoons in which these habitats are described. This new knowledge constitute an important management and spatial planning tool on both a local and regional scale.