International audienceAfter its massive introduction in the seventies in France Crassostrea gigas has became the main production of French oyster farming. From the early 1990's, C. gigas has started to spread many sites of Brittany and Normandy and, thanks to climate warming, its population has dramatically increased leading to a general invasion and to deep changes in ecosystems and biodiversity. A research program called PROGIG has been set up to evaluate the dynamic of this proliferation on French Channel and Atlantic coasts, and to identify its interactions with marine ecosystems and human activities. This paper presents the GIS implemented to integrate the data collected during field surveys of oyster populations, and the results of a ...