The MuMiFaST project gathers European expertise on the value chain related to undersized non-uniform mussel biomass compared to mussels produced for human consumption. As either a new industry utilizing undersized mussels, or as one focused on maximizing production of heterogeneous mussel biomass, this marine bioresource can be produced sustainably, and exhibits promise in use as a high quality animal feed and in nutritious value-added food products. The primary needs for innovation in this industry are related to post-harvest preprocessing and processing of large volumes of heterogeneous mussels to a quality standard suitable for the aquaculture feeds industry. In this project the partners will develop advancements in the supply system of blue bioeconomy value chains of mitigation mussels between TRL3-6, providing proof of concept of new perspectives on waste reduction and utilization of the entire biomass towards production of highly quality ingredients for the aquaculture feed industry. Application of this undersized mussel model in a wider European context will be explored through the partner organizations here and broad stakeholder engagement.