Marine ecosystems are complex, subject to high local and global pressures. In the English Channel and the North Sea, the effects of climate change are already visible in the distribution of many species. In addition, the occupation of space is linked to many human activities including traditional activities such as fisheries and more recent such as granulate extraction or harbor sediment deposits. Moreover, the construction of offshore wind farms (OWF) is booming. Food webs are formed by the different intricated food chains. Their characterization allows to understand the complexity of ecosystem functioning and its changes under different pressures. For this purpose, the emergent properties of these networks are characterized by numerical indices called ENA (Ecological Network Analysis). The methods of estimating flows in food webs before/after the simulated impact (OWF or climate change), as well as the analysis of changes in the values of ENA indices are been presented. These methods are based on a mean square meter (LIM-MCMC) or on 2D approaches (Ecospace). We propose the use of these methods for studying the cumulative impacts of OWF and climate change effects on the distribution of species. The results show that the reef effect associated to the turbines may bring a better resilience of the system. However, these results only consider trophic interactions and not all physical and ecological impacts.