A preliminary LCA of rainbow trout farming: a Case Study on freshwater aquaculture in Italy

Marine and freshwater fish aquaculture plays a significant role globally in ensuring food security. In 2020, marine fish accounted for 39% of the total aquatic animal production, while freshwater fish constituted 33% of total aquatic animal production. This trend is particularly notable in Europe, where species like rainbow trout, seabass and seabream are extensively farmed. Among them, rainbow trout is one of Europe’s top five farmed species in terms of production and in Italy it is the main breeding species. However, despite the sector’s significance, there is a gap in the literature concerning the potential environmental impacts generated by farmed rainbow trout (e.g., nutrient discharge, use of non-renewable resources, overexploitation of fish stocks). To cover this gap, this study aims to assess the potential environmental impacts of the rainbow trout production process, accounting a cradle to gate approach: from egg to grown fishes, ready for market. These are assessed applying the Life Cycle Assessment (LCA) method, in order to identify the main hotspots of process. The case study is conducted on trout farming using primary data provided by an Italian company that encompasses the entire production process. The data are collected through questionnaires and site visits, focusing on feed consumption, natural resource utilization, and emissions generated. The main findings of this study allow to identify the key environmental hotspots along the different stages of trout production, providing a basis for informing decision-making on which processes could be optimize and improved to mitigate environmental impacts effectively.