The Stagnone of Marsala, which is located in the south of Trapani, is a vast marine and lagoon area that includes the Isola Grande and the islands of Santa Maria and San Pantaleo (Mozia). The morphology of the area suggests recent subsidence movements, largely submerging a wide alluvial plain. In the lagoon environment, there are two inlets that allow the circulation of seawater. The marine waters are characterized by a rich meadow of Posidonia oceanica and a mixed population of Caulerpa prolifera and Cymodocea nodosa. The area is known for its high biodiversity and it plays an essential role as a nursery and habitat for numerous fish species. The presence of the mollusk Pinna nobilis and various marine species makes it an area of significant ecological and scientific interest.