Distribution of the Mediterranean ribbed limpet Patella ferruginea Gmelin, 1791 along the Ligurian coast and implications for conservation actions

Patella ferruginea is a limpet endemic to the Western Mediterranean Sea. It is presently considered the most threatened marine macroinvertebrate in the region and has been included in several international conservation directives. Its populations were widespread throughout the Western Mediterranean in the late Pleistocene period, and remained broadly distributed until the 19th century. Presently this species is confined into small populations in a few restricted areas due to human harvesting for food and baits, construction of coastal infrastructures and the effects of seawater pollution. In particular, the species is reported as presently disappeared from the whole of the Italian continental coast and measures are in progress to reintroduce the species through translocation and reproduction in controlled conditions along the Ligurian coasts of the Northwestern Mediterranean. Recent surveys implemented in the framework of the present work along the Ligurian coasts, to assess the most suitable sites for reintroduction, resulted in the discovery of 32 specimens of this endemic limpet, which previously was thought to have vanished from the area. These findings shed new light on the ability of species to naturally disperse, the relevance of the measures set in place to restore presently rarefied populations and may provide information to aid in the selection and management of sites within the Natura 2000 Ecological network.