Système d'Information Géographique (SIG) au Laboratoire Conchylicole de Poitou-Charentes (LCPC) : exemples d'utilisation et travaux en cours pour l'aide à la gestion spatiale des élevages conchylicoles

The Geographic Information System on the Charentais sounds was one of the first developed by the research group SILLAGE (DEL/AO). The coastal regional shellfish laboratories are pursuing their efforts to enrich and develop the georeferenced databases, to reach a coherent and comprehensive meta-database. The shellfish resarch laboratory of Poitou-Charentes (LCPC) from IFEMER's departrnent of aquaculture resources has developed research themes based upon the GIS use, a powerful tool for spatial analysis. Those programs are commonly developed by ail shellfi sh coastal laboratory at IFREMER's level, prompting us to suggest the applications' transfers to other research units. Various applications and developments using Arc View software were reviewed in this report. The GIS itselfwas described, as weil as complementary equipments required to assess continuously and in-situ environmental variables. The various applications in spatial analysis (e.g., assessing sediment volumes when channel dredging, indices at the leasing ground unit, spatial and temporal sampling strategy ... ) were explained. The on-going works have mainly a shellfi sh ecosystem management approach : the first example concems a tool for spatial management of stocking biomass, by using a computerized image analysis of aerial coverage connected to the GIS as weil as an historical data base of the previous stock assessments surveys using ACCESS software. The second one focus on assessing the balance between the carrying capacity and the local rearing biomass, by using the in-situ continuous environmental monitoring, and the mussel physiological model (STELLA & MA TLAB softwares). This facilitated estimating food depletion by the mussel stocking biomass.