International audienceAim: Identifying the potential of marginal habitats for species conservation is of key importance when their core high-quality habitats are under substantial disturbances and threats. However, there is currently a knowledge gap on how useful marine marginal habitats may be for conserving endangered marine species. Here, we investigate the potential of groundwater-fed coastal areas for the conservation of the queen conch, an economically and culturally important marine gastropod. Location: The inlet of Xel-Há, typical of groundwater-fed coastal areas widely distributed along the Yucatan Peninsula coast in Mexico and partially protected by a network of marine protected areas. Methods: We tracked 66 queen conchs (Lobatus ...