The rise of aquaculture by-products: Increasing food production, value, and sustainability through strategic utilisation

Since 2000, the use of wild fish inputs in the production of farm raised fish outputs, also known as the Fish In: Fish Out (FI:FO) ratio, has been a primary concern of the sustainability dialogue surrounding aquaculture production. Far less attention has been placed on the sustainability of downstream processing, including how by-products are managed. This paper contributes new information on the current utilisation of aquaculture by-products in a case study on the Scottish Atlantic salmon industry. The findings show that there is considerable potential to increase the sustainability of the industry through maximising human edible yield by strategically managing by-products. Supporting the movement towards the full utilisation of by-products, this paper goes a step further by emphasising the need to maximise their use in human consumption and select animal feeds, highlighting the economic, food security, and environmental benefits of doing so. Through exploratory scenarios based on the case study, the paper identifies that Scotland could increase food production from fish farming by over 60%, increase by-product revenue by 803%, and increase the industry bottom-line by over 5%, all without having to put any new cages in the water, or use any more marine resources. As the aquaculture industry moves into a new era of production and processing, where a diverse range of products can be produced from a single species, sustainability will be sought throughout the value chain. It is hoped that the ideas raised within this paper will encourage further discussion and collaboration on this topic going forward