Establishing an innovative and transnational feed production approach for reduced climate impact of the aquaculture sector and future food supply

LIMAQUA results in an innovative process for converting and recirculating aquaculture side-streams (sludge and wastewater) in algae (Galdieria sulphuraria)-based feed production for aquacultures. In conventional aquaculture, feed production is responsible for 50% of greenhouse gas (GHG) emission. The aim is to substantially reduce GHG emission by considering geographic and site-specific characteristics (temperature, sunshine duration etc.) and to design site-specific phototrophic or heterotrophic Galdieria sulphuraria cultivation for almost completely ingestible feed. CLIMAQUA builds on knowledge gained regarding aquaculture and feed production, and involves partners from Norway, Germany, Kenya and South Africa in order to broaden the applicability, not limiting the approach to a certain geographic area and assessing climate impact of feed production in different climate zones. Concretely, CLIMAQUA considers the following aspects:Technological aspects resulting in low carbon footprint solutions1. Production of aquaculture feed that ensure efficient feed conversion and beneficial reduced environmental impact, 2. valorisation of side-stream from aquaculture (e.g., sludge) as feedstocks for Galdieria sulphuraria biomass and eventually feed production instead of incineration, anaerobic digestion or landfilling, which activate carbon and nitrogen emissions, 3. valorisation of wastewater from aquaculture sites, rich in nitrogen and phosphorous, as nutrient sources for Galdieria sulphuraria biomass production and eventually feed production, 4. designing an environmentally favourable feed production, rather than resource demanding as well as 5. carrying out decentralized fish feed production (on place processing and minimal transportation).Non-technological aspects resulting in changes in supply chains and food system resilience6. assessing socio-economic impacts and consequences of climate change on aquaculture in Africa and Europe, 7. minimising the interactions of climate change on food systems by climate adapted production of feed and fish, 8. developing resilient food systems under consideration of changing food needs by demand-oriented aquaculture, 9. decoupling of agriculture from aquaculture by substituting agriculture-based feed with Galdieria sulphuraria-based ones and eventually mitigation of agriculture-based GHG emissions as well as 10. transfer of knowledge to other regions worldwide.The transnational cooperation is characterized by an intense knowledge exchange from the South to the North and vice versa. South Africa and Kenya cope with climate situations challenging the constant supply of food. Norway established efficient aquaculture food systems and utilization of side-streams. Contrarily, Norway is missing knowledge to deal with climate change in the future, while South Africa benefits from the results from efficient side-stream utilization. This cooperation strengthens regional capabilities and contributes to food security under climate change within 1.5 or 2 °C until 2050 and beyond.