Governance and public policies of coastal water quality in the « Pertuis Charentais » The coastal area of the Charente-Maritime region is highly attractive and mainly used for economic and recreational activities. Each year, 3 million tourists visit this territory stretching over 460 kilometers of coastline. According to the National Statistics Institute, more than 6.5% of the local economy relies on tourism. The Pertuis Charentais, which are the receptacle of three rivers (the Sèvre-Niortaise, the Charente and the Seudre), create a good natural environment for shellfish farming. The shellfish sector is an additional structuring activity. It shapes land and sea territories and contributes to the development of the department identity. In terms of economics, shellfish farming achieves a turnover of 350 million euros and generates nearly 25,000 direct jobs. 23% (50,000 tones) out of the 217,000 tones of shellfish sold in 2016 were shipped by companies located in this department. Given the importance of its coastal activities, the water quality is of major importance and represents a challenge for the Charente-Maritime. Poor water quality is detrimental to the life of the biodiversity living there. Poor conditions will thus affect the water, its usage and the various environments. People's health and safety may also be impacted. If a potential toxic bacteria or microscopic algae was likely to develop, bathing could become dangerous and be prohibited. Poor chemical status could lead to the closure of shore fishing areas, having consequences on both professional and recreational fishing. Bacteriological contamination could affect aquaculture meaning the coastal shellfish could not be sold. These degradations are Chapter written