Life cycle assessment of aquaculture salmon

The purpose of this analysis is to perform a “cradle to gate” Life Cycle Assessment (LCA) for aquaculture salmon products. The results from this study as well as literature review done in work package 1.1 are used to propose Key Environmental Performance Indicators (KEPIs) for the aquaculture supply chain. This is done in order to develop a system to simplify data collection and information requirements oriented specifically to every stage involved in the life cycle. The KEPIs will be used to identify relevant input data to an innovative software tool (SENSE tool) to provide comprehensive environmental information for small and medium size enterprises (SMEs).
This case study is valid for the operation of a hatchery and a salmon farm located in Iceland and a smokehouse in France. The LCA was done for two different functional units: 1 kg of fresh aquaculture salmon, head on gutted (HOG) and 1 kg of smoked aquaculture salmon fillets. Furthermore, two transportation scenarios were analysed for the fresh aquaculture salmon, sea freight and air freight. The fresh salmon (HOG) is transported from the aquaculture farm in Iceland to Europe where it is delivered at retailer or for secondary processing. Allocation between main products and by-products at hatchery, aquaculture farm and smokehouse was done using economic approach based on the shares of product in annual turnover. Allocation is done in accordance with ISO 14044 and recommendations from ENVIFOOD Protocol (2012).
The midpoint impact assessment methods identified in task 1.3 of the SENSE Project were used for the environmental impact assessment in this study (Aronsson et al., 2013). The Life Cycle Impact Assessment (LCIA) is done for the impact categories: Climate change, eutrophication, acidification, human toxicity, ecotoxicity, land use, abiotic resource depletion and water depletion.
The LCIA shows that for fresh salmon (HOG) transported from Iceland to Europe by sea freight the aquaculture farm including the feed production is by far the dominant life cycle stage in all impact categories. For most of the impact categories this is due to the harvesting and processing of feed ingredients (marine and crop). For the impact category marine eutrophication it is however the release of organic matter to sea which is the major cause of impact at the farm and for the human toxicity potential (non-cancer effects) it is the transportation of the feed from feed mill to the farm.
For the fresh salmon (HOG) transported to Europe by air freight the aquaculture farm is not as dominant but it is still the main contributor to environmental impacts in seven of the 11 assessed impact categories, i.e. for terrestrial, freshwater and marine eutrophication, human toxicity (cancer effects), ecotoxicity, land use and water depletion. For the climate change impacts, acidification, human toxicity (non-cancer effects) and resource depletion, the transportation phase is the main source of impact.
The results for the smoked salmon fillet show that for nine impact categories the aquaculture farm life cycle stage is the main contributor of environmental impacts, mainly due to the feed. In two impact categories, human toxicity (non-cancer effect) and water depletion the operation of the smokehouse in France is the main source of impact.
The allocation method used in this study (economic allocation) is recommended for the SENSE tool.
KEPIs were identified for the aquaculture salmon supply chain and the indicators that are common in all life cycle stages are fossil fuels and electricity use. Feed is identified as a KEPI for the hatchery and the aquaculture farm as well as water use which is also identified for the secondary processing. Additionally, organic waste to sea from the aquaculture farm is identified as a KEPI.
The regional variation affects some of the identified KEPIs. For acidification, eutrophication and water depletion regionalised characterisation factors are available for different countries. It is suggested that these will be applied in the SENSE tool. For other regional impact categories regionalised characterisation factors are not available yet. Environmental impacts differ for electricity in different countries and information on the different electricity mixes is available and it is important to implement these in the tool. It is recommended that Life Cycle Inventory (LCI) background data for different types of aquaculture feed and feed ingredients will be generated and implemented in the tool. This is necessary for the tool to be accessible, simple and easy to use. Furthermore, datasets for emissions of organic matter to sea need to be available.