Seas and oceans play a crucial role in the overall functioning of the earth. Despite the increasing human pressures and impact on the marine ecosystem, oceans still remain the least explored and studied realm on earth. Multidisciplinary scientific research is crucial for understanding global processes and ecosystem functioning. This knowledge is needed for sustainable development of our growing maritime economies, and is essential for the prospective management of ecosystems towards a sustainable future. The ‘Thematic chapter’ gives an overview of marine research in a global, European and local context. It maps the marine research landscape in Flanders and in Belgium related to research capacity, research resources and knowledge output. More information about the available expertise within the Belgian marine research groups and their relevant research infrastructure can be consulted by clicking ‘Research groups’ (see also Brochure) and ‘Infrastructure’ (see also Catalogue), respectively. Funding opportunities for marine research and innovation projects are listed under ‘Funding’ (see also Guide on funding instruments). The European policy with respect to marine research is discussed in more detail under ‘Legislation’, while the figures and background data can be consulted in an interactive way by clicking ‘Interactive graphs’.