Diapontia is a small island complex situated at the north-westernmost part of Greece, in the NE Ionian Sea. The complex consists of three main (populated) islands (Othonoi, Erikousa and Mathraki) and some smaller uninhabited rocky islets (Trachia, Platia, Diaplo, Diakopo). This fully marine site extends at depths of 0-50 m and covers an area of 153.38 km2. This marine area is characterized by the existence of Posidonia beds, mainly in depths between 5-30m.