Comparative life cycle assessment (LCA) of raising rainbow trout (Oncorhynchus mykiss) in different production systems

The production of rainbow trout (Oncorhynchus mykiss Walbaum 1792) is practiced in different production systems including extensive system (ES), intensive system (IS) and recirculating aquaculture systems (RAS). These production systems are different in their quantitative requirements of resource utilization and subsequent output and emissions that impact the environment. In this paper, consequential life cycle assessment (LCA) is used to analyze the environmental impact of rainbow trout production using these production systems in an attempt to determine the relative performances and identify options for future improvements. The life cycle impact assessment (LCIA) indicate that impact from four impact categories chosen, RAS showed the largest impact in global warming (GWP), acidification (AP) and land competition (LC), while its impact on eutrophication (EP) and water-use was the lowest relative to ES and IS. This signified that while RAS has the capability to reduce impacts in the EP category by avoiding water emissions, the increased use of energy for water filtration and reuse increases impact through global emissions. However, sensitivity analysis revealed that RAS has the potential to reduce the overall impact when using a marginal energy source based on wind power as compared to ES and IS. In conclusion, impacts which are specific to aquaculture need to be considered in LCA to draw comprehensive analysis of the impacts. In addition, identification of the underlying problems of the different impacts is important in finding solution leading to sustainability of aquaculture. (C) 2012 Elsevier B.V. All rights reserved.