Accounting for life cycle inventory and methodological choice uncertainty in a comparative Life Cycle Assessment: what are the environmental trade-offs for small and medium enterprises adopting Integrated Multi-Trophic Aquaculture?

Aquaculture is one of the fastest growing food sectors at present. European aquaculture, although growing marginally, is facing the challenge to do so in a sustainable manner. Integrated Multi-trophic Aquaculture (IMTA) is a... [ view full abstract ]

Aquaculture is one of the fastest growing food sectors at present. European aquaculture, although growing marginally, is facing the challenge to do so in a sustainable manner. Integrated Multi-trophic Aquaculture (IMTA) is a technology regarded as an environmental management concept that can minimize the environmental impacts of coastal ocean aquaculture, i.e. managing nutrient emissions to seawater from intensive open sea monoculture aquaculture, while expanding the economic base of the farms. In this study we investigate the question: what are the environmental trade-offs for small and medium enterprises (SMEs) considering to innovate their monoculture aquaculture practice towards IMTA? To answer this question we apply a novel LCA approach to a case study of an SME producing fish and staring-up an IMTA system. We implemented a comparative Life Cycle Assessment (LCA) approach including uncertainty analysis and use two statistical methods to quantify and propagate two crucial sources of uncertainty in the assessment: life cycle inventory data (Henriksson et al. 2013) and uncertainty due to the choice of allocation method (Mendoza Beltran et al. 2015). Quantification of inventory data uncertainty with statistical testing in a comparative LCA has already been proposed and applied (Henriksson et al. 2015a, 2015b). The combination of this technique with the pseudo-statistical method to propagate choice uncertainty is a novel approach that supports more robust environmental assessments of the trade-offs between IMTA and monoculture fish production. With the considered setups for both systems, we found evidence of a marginal difference between the impacts of IMTA and monoculture production of fish. However, statistical testing of twelve impacts showed that only mean impacts for climate change are significantly different for both alternatives and favor IMTA production. Technical parameters (scale, integration and species) and LCA methodological parameters determined the environmental trade-offs between IMTA and monoculture fish production.

References

Henriksson, P.G.J., J. Guinée, R. Heijungs, A. Koning, and D.M. Green. 2013. A protocol for horizontal averaging of unit process data—including estimates for uncertainty. The International Journal of Life Cycle Assessment 19(2): 429–436. http://link.springer.com/10.1007/s11367-013-0647-4.

Henriksson, P.J.G., R. Heijungs, H.M. Dao, L.T. Phan, G.R. de Snoo, and J.B. Guinée. 2015a. Product carbon footprints and their uncertainties in comparative decision contexts. PloS One 10(3): e0121221. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=4363321&tool=pmcentrez&rendertype=abstract. Accessed August 26, 2015.

Henriksson, P.J.G., A. Rico, W. Zhang, S. Ahmad-Al-Nahid, R. Newton, L.T. Phan, Z. Zhang, et al. 2015b. Comparison of Asian Aquaculture Products by Use of Statistically Supported Life Cycle Assessment. Environmental Science and Technology 49(24): 14176–14183. 

Mendoza Beltran, A., R. Heijungs, J. Guinée, and A. Tukker. 2015. A pseudo-statistical approach to treat choice uncertainty: the example of partitioning allocation methods. The International Journal of Life Cycle Assessment. http://link.springer.com/10.1007/s11367-015-0994-4.