International engagements call for the designation of representative networks of Marine Protected Areas (MPAs) by 2020. Up to now, numerous studies have proved the performance of MPAs for both protecting local biodiversity and supporting fisheries by adults spillover. However, these studies have also pointed out that many important factors are still overlooked. Indeed, MPAs effectiveness is also conditioned by their role as dispersal origin of larvae to replenish nearby depleted fished areas. Thus, understanding the connectivity patterns among them and with unprotected sites is essential to build effective MPAs networks. To do so, the present project will propose an original and complete survey based on combining complementary methodological approaches (ecology, dispersal dynamic model and genetic connectivity), with two critical questions in mind: which Mediterranean areas received the fish larvae issued from a MPA? Where do the fish observed in a MPA come from? We will consider the Cabo de Palos – Islas Hormigas Marine Reserve (CPMR, Spain, SW Mediterranean). This area presents a very dynamic hydrography; the winds and currents directions are therefore likely to strongly influence the larval dispersal pattern around the MPA. We will develop a dynamic model using currents and temperature data to simulate the dispersal of fish larvae during their pelagic stage. Then, the model results will help us to target sites at regional scale (tens of km’s) where larvae issued from CPMR could settle, and areas within this geographical range likely to act as sources of larvae replenishing CPMR. Both adults and larvaes will be collected through field work (diving and fisheries data) in all these areas, and genetic analyses will be performed to identify the parent-offsprings pairs. The results will allow us to better understand the relationships between distinct coastal areas through their fish exchanges and to underline the MPA role as sources of fishes for the marine fisheries.