European seabass (Dicentrarchus labrax) is an important fishery resource for small-scale and recreational fishing in the Mediterranean Sea. Despite its economic importance for professional fishing field, knowledge of the spatio-temporal distribution of the species during its ontogeny remains insufficient. Small-scale and recreational fishermen supported by several thesis studies have highlighted a decline in stocks within the Marine Natural Park (Cambra, 2022). The extension of this phenomenon to the whole of the French Mediterranean Sea (ConnectLeucate, 2021) has led to the creation of a project to identify important fisheries functional zones (ZFHI) for European seabass. The aim of LOUYETU is to combine expert opinion and acoustic telemetry data to identify the key zones in the European seabass life cycle and ultimately establish management methods adapted to preserving the resource.