The conflict activities observed in the marine environment, such as renewable energy production, aquaculture and tourism, highlight the need for more coherent management at the cross-sectoral level so that human activities in the ocean can be carried out in an efficient, safe and sustainable way. Along these lines, this paper focuses on identifying the interlinkages between the main natural resources in the marine environment, namely water, energy, marine land use, food and climate, by considering them to be nexus elements (Marine NEXUS). In addition, it tries to determine the interactions among them in order to identify the pressures on marine natural resources and their potential for use in the development of coastal communities. An analysis of the estimated interlinkages and complex pathways is performed, based on their impacts on every aspect of the marine environment in Greece. One of the main conclusions drawn from this analysis is that seawater has a very strong impact on food (i.e. the fisheries and aquaculture, in comparison with energy production in the sea). The choice of activities that may be implemented in the oceans (land use element) has a great impact on the food (e.g. fish quantities) and water (e.g. marine pollution) elements of the Marine NEXUS. The influences and the dependences of these five elements are quantified in order to show that the efficient management of natural resources requires a holistic approach that considers the cumulative impacts of the complex interactions among them.