The continuous increase in global population and living standards, is leading to an increase in demand for food and feed resources. The world’s oceans have the largest unlocked potential for meeting such demands. Norway already has an extensive aquaculture industry, but still has great ambitions and possibilities to develop and expand this industry. One of the important topics for improving the value chain of Norwegian aquaculture is to secure the access to feed resources and to improve the environmental impacts. Today, most of the feed-protein sources used in aquaculture are imported in the form of soy protein. The research project Energy efficient PROcessing of MACroalgae in blue-green value chains (PROMAC) aimed, among other research questions, to investigate cultivated seaweeds as a potential raw material for fish feed. This paper assesses Life Cycle Analysis (LCA)-perspectives of scenarios for future seaweed production of feed-protein for fish and compares this with today’s situation of imported soy protein for fish feed. The insights from the LCA are very important for the configuration of the entire production value chain, to ensure that the environmental aspects are taken into account in a holistic fashion.