Fish and meat production and processing will grow drastically in the coming decades. In aquacultural systems, insects are gaining interest as feed to provide a sustainable alternative to the fishmeal paradox, whose production leads to high consumption of resources and negative environmental impacts. Within the scope of this study, the production of fish feed from Hermetia illucens larvae and Lemna minor in an inline recirculating aquaponics model for urban sites was developed and optimized, which efficiently combines waste and environmental service concepts in one production system. At the same time, the value chain produces high-quality, market-accessible raw materials for the fish feed industry. All investigations were accompanied by a comparative Life Cycle Assessment (LCA) to measure and compare ecological effects to finally result in sustainable alternatives. The results achieved in this research show that fish feed based on Hermetia illucens and Lemna minor can have the potential to be ecologically competitive or more sustainable than standard feed. It should be noted that the comparison here represents the results of the project on a pilot scale. Various optimization potentials were shown, which are essential for the large-scale implementation of the breeding of both species as well as their processing up to the fish feed pellets.

Biomass waste and waste-derived feedstocks are important resources for the development of sustainable value-added products. However, the provision and preparation of biomass as well as all possible downstream processing steps need to be thoroughly analyzed to gain environmentally sound and economically viable products. Additionally, its impacts are substantially determined by decisions made at early development stages. Therefore, sustainability assessment methods can support to improve the production process, reduce waste, and costs and help decision-making, at the industrial as well as policy levels. Life Cycle Assessment (LCA) is an analysis technique to assess environmental impacts associated with all product's life cycle stages. It is a well-established tool to drive development towards a sustainable direction, however, its application in the earlier research phase is surrounded by practical challenges. The overall objective of this paper is to provide an understanding of the environmental issues involved in the early stages of product and process development and the opportunities for life cycle assessment techniques to address these issues. Thus, herein two LCA case studies are presented, dealing with novel approaches for food and feed supply through implementing the valorization and upcycling of waste and side-streams, respectively. In both case studies, LCA is used as a decision support tool for R&D activities to launch environmentally sound products to market, as well as to highlight the usefulness of LCA for identifying environmental issues at an earlier stage of development, regardless of product, process, or service.