The Fragmented Landscape of Shrimp Life Cycle Assessments: Uncovering Methodological Dependence and Analytical Blind Spots

Life cycle assessment (LCA) of shrimp aquaculture is hampered by widely divergent results, with reported impacts varying by more than fiftyfold across key categories. This systematic review of 16 peer-reviewed LCAs provides quantitative evidence that much of this divergence is driven by analytical choices rather than on-farm performance: In this case study covering 37 farming cycles, methodological differences in shrimp LCAs induced larger changes in global warming estimates for identical farm data compared to different farming practices. This issue is compounded by a lack of transparency, with only five of the 16 studies providing sufficient data for full reproducibility. We find that this methodological dominance is amplified by analytical blind spots, as most studies neglect critical environmental pressures such as land use change, biodiversity loss, and antibiotic use. To build a robust and comparable evidence base, we recommend representative studies, specific methodological harmonisation, mandatory inclusion of neglected impact categories, and improved reporting transparency. These improvements are essential for LCA to accurately guide the sector towards more sustainability.