Aquaculture is essential to meet the increasing demand for nutritious seafood. The European (European Economic Area (EEA) + United Kingdom (UK)) aquaculture industry is highly dependent on aquafeed input, which represents the majority of the environmental impact and production cost. Aquafeed formulations consist mostly of a combination of marine and plant-based ingredients. Driven by economic and sustainability incentives, there has been a shift from marine ingredients, towards plant-based ingredients, and smaller inclusions of (fish) by-products and novel feed ingredients.
We applied an Index Decomposition Analysis (IDA) IDA to assess the changing environmental impact of European aquaculture from 2000 to 2020. Five finfish species, Atlantic salmon, rainbow trout, gilthead seabream, European seabass and common carp included as these species represent most of the European aquaculture production.
We find a substantial increase in global warming potential (320%), land use (595%), water consumption (256%), marine eutrophication (624%) and freshwater eutrophication (436%), while fish use was reduced by only 13%. Most of the increase in global warming potential, land use water consumption, marine and freshwater eutrophication was the result of marine ingredient substitution through changing feed composition. The reduction in fish use was mostly attributed to the substitution of, and improved by-product utilization for marine ingredients.
The substitution of marine ingredients with plant-based ingredients to date has not been an environmentally sustainable transition. Although it has reduced marine resources overall, the pressure has disproportionally shifted towards terrestrial systems. A shift mostly attributable to t he use of two terrestrial plant based ingredients, soy protein concentrate and rapeseed oil as a replacement of fishmeal and fish oil.