By the end of 2020, i.e. twelve years after the installation of the first wind turbines in the Belgian part of the North Sea, an installed capacity of 2.26 Gigawatts (GW), consisting of 394 offshore wind turbines and covering 238 km², will be operational in the Belgian part of the North Sea (chapter 1). They are expected to produce an average of 8 TWh annually, which is around 10% of the total national electricity demand or nearly 50% of the electricity needs of all Belgian households. Although no new projects are scheduled in the next years, long-term developments include an additional zone of 285 km² for a production capacity of ~2 GW of offshore wind energy which has been delineated in the new marine spatial plan. With 523 km² reserved and planned for offshore wind farms in Belgium, 344 km² in the adjacent Dutch Borssele zone, and 122 km² in the French Dunkerque zone, cumulative ecological impacts will undoubtedly continue to be a major concern in the years to come. We hence continue to be ever more faced with the challenge to optimise measures to combat the energy crisis in the light of combatting the biodiversity crisis. Tackling this challenge will necessitate the generation of new knowledge as well as a maximum uptake of existing and new knowledge to facilitate an environment-friendly management of offshore renewable energy developments, hence inspiring priority monitoring, research and management. This knowledge should cover a broad range of ecosystem components from soft sediment and (artificial) hard substrate invertebrates and fish to seabirds and marine mammals, as well as their interactions, all of which are impacted by offshore renewable energy developments in different ways.