There is considerable interest in the Netherlands and Europe in the potential of seaweed as source of food, feed and biomass for a biobased economy. The aim of this study is to evaluate the macro-economic effects of increasing seaweed production in the North Sea. The explorative analysis showed that the seaweed sector in NSR is in its nascent stages. Despite an modelled 10% annual growth over next 30 years, production in the North Sea Region remains too small to have any visible impact on global markets for seaweed. The size of the seaweed sector remains too small to function as alternative source of protein in consumer diets. The Modular Applied GeNeral Equilibrium Tool (MAGNET) was used in this study. MAGNET is a recursive dynamic, multi-regional, multi-commodity CGE model, covering the entire global economy. The best available data from FAO and information from scientific literature were used. We emphasise that results are indicative and should be used as such. More reliable data collection and improved insights in the different cost structures in various North Sea region countries can improve the accuracy of the simulations.