Mapping Biodiversity Impacts of Norwegian Salmon Feed Across Global Trade

Global salmon aquaculture depends heavily on feed ingredients derived from wild-caught fish and agricultural crops. Both come with complex environmental impacts and trade-offs. This study investigates the regionalized environmental impact of salmon feed production for Norwegian aquaculture and which countries import impacts through consumption.

We address three  questions: i) How do  resource use and emissions affect biodiversity based on feed ingredient and sourcing region?; ii) How significant is the relationship between the mass and biodiversity impacts of feed ingredients?, and iii) How are biodiversity impacts distributed or attributed among consumer countries?

We combine life cycle assessment (LCA) with producer-level data, and trade flows. Preliminary results show that over half of the feed ingredients originate from Europe by mass, with Norway being the largest contributor with raw marine ingredients. South America ranks second, with Brazil leading in vegetable protein exports. Although Norway and Brazil contribute similarly in terms of mass (> 15%), their environmental impacts differ: Norway’s inputs show higher impact on marine ecotoxicity and climate change, while soy production shows higher impacts in marine eutrophication and land stress. These impact categories will be expanded to include marine ecosystem effects, such as seabed damage and ocean acidification, to provide a more comprehensive assessment.

From a consumer standpoint, the analysis incorporates both intermediate and final consumption stages to trace how environmental impacts are distributed along the supply chain. Trade data are used to link production in Norway with importing countries to capture the flow of products through processing before reaching final consumers in central Europe. Even though consumer demand and re-export patterns are challenging, including these two stages represents the main regions of demand, which is considered as a good proxy for impact allocation.

Key limitations include the lack of transparency in ingredient sourcing and incomplete inventory data. Additionally, existing inventories for LCA tend to focus on energy use and greenhouse gas emissions, often overlooking other critical impact categories. This study partially addresses these gaps by developing novel inventories, and assessment of supply chains, which contributes to a comprehensive assessment of salmon production and consumption.