The Ligurian Sea region is highly valued among Mediterranean countries, known for its physical beauty and its importance in supporting cetacean species. The ecological importance of the area between western Liguria, the west coast of Corsica and southern France has been highlighted by systematic surveys of large marine fauna since the 1980s, and the area has been revealed as an exception to the generally low productivity of the Mediterranean Sea. Around the same time it came to be realized that a number of human activities such as shing with pelagic driftnets, naval exercises and maritime traf c were posing signi cant threats to marine life, including cetaceans. These circumstances provided the impetus for the proposed creation of a large international marine protected area to safeguard the integrity of the pelagic ecosystem and associated biodiversity. This resulted in an agreement signed in 1999 by France, Italy and Monaco that established an 87,000 square km international protected area known as the “Pelagos Sanctuary for Mediterranean Marine Mammals”. In the years since, Mediterranean governance as well as regional and European marine conservation policies have evolved beyond recognition. Changes include the disappearance of the Mediterranean high seas from Sanctuary waters and the development within the region of a number of novel initiatives at European and Mediterranean levels. These include the entry into force of ACCOBAMS, the development of the “ecosystem approach” planning under the framework of the Barcelona Convention, the identi cation of ecologically or biologically signi cant areas (EBSAs) under the Convention on Biological Diversity (CBD), the obligation for European member states to implement national marine conservation strategies, and the onset of marine spatial planning (MSP).