Résumé
The Mediterranean coastal zone represents an important socio-economic and ecological space undergoing strong pressures. The ports represent both areas of heavy pollution related to the density of activity but also areas of refuge for many biological species. From November 2019, four ports in the Gulf of Aigues-Mortes (Palavas, Pérols, Port-Camargue and Carnon) conducted a mutualized dredging falling within the regional scheme of dredging in Occitania. The ports studied are of different sizes (130 to 5000 berths). These dredgings are based on the recovery of the dredged sediments by distinguishing between ports with sand inputs of wind or current origin (Port Camargue and Palavas) and ports confronted with inputs of sand and mud, which may be contaminated by the port activity and/or the watershed (Pérols and Carnon). The monitoring of the chemical and microbiological quality of the port waters before, during and after the dredging operations allowed us to determine the state of the water quality of the four ports and the impact of these operations on the resuspension of contaminants and the possible disturbances induced.