Offshore wind farm development has become a key measure of energy transition in recent years. Coastal territories are particularly favorable to the development of offshore wind farms due to their high energy potential. However, these areas are also hotspots of biodiversity, provide attractive landscapes and are under strong anthropogenic pressures. Preserving and sharing the natural and cultural resources of coastal territories while intensifying renewable marine energies, represents one of the most important challenges for future management of coastal environments. Consequently, systemic models that consider all the effects of offshore wind farms on ecosystems and society are essential. Here, we propose a conceptual model for studying these effects, by mobilizing the concept of ecosystem service in a systemic and integrated assessment approach. To that aim, we reviewed the literature and compiled experts' knowledge in order to characterize the effects of offshore wind farms on food webs during the construction and operation phases. Then, we analyzed the contribution of trophic compartments on ecosystem functions, ecosystem services and beneficiaries, and how offshore wind farms modify the relationships between these compartments of the marine coastal social-ecological systems. Our approach helps identify the causal chains that generate the most important modifications in this system. This information could then be used to predict impacts of offshore wind farms on ecosystem services, and to suggest management trade-offs. This study reveals the need for further studies relating marine biodiversity to ecosystem services, and developing systemic approaches at different scales. The analysis of the effects of offshore wind farms on ecosystem services is crucial since it is linked to strong ecological, socioeconomic and political issues.