Ecological role and exploitation of Posidonia oceanica in the Mediterranean area

The paleoendemic seagrass Posidonia oceanica (L.) Delile (Posidoniaceae) represents a key species of the most important and productive ecosystem in subtidal habitats of the Mediterranean Sea. This species is the most common seagrass in Sicily where it forms dense and extensive beds, which are characterized by high coverage and primary production values, along the Western coasts. According to phenological processes, the beaching of P. oceanica residues (banquette) represents a great environmental, economic, social and, hygienic problem, conflicting with a number of activities (tourism, bathing establishments, etc.). Even though seagrasses play a fundamental ecological role in limiting coastal erosion and promoting the origin of the coastal dunes, the presence of P. oceanica residues along the coasts can negatively decrease the tourism value of beaches. As a result, according to national and regional laws and guidelines, local authorities are required to remove banquette and to accumulate it in landfills. In this work, the ancient exploitation and current uses of P. oceanica residues are reported according to literature and field data.