Industrial aquaponics systems (IAS) represent an emerging solution for sustainable protein and vegetable production, offering closed-loop integration of aquaculture and hydroponics. Despite their theoretical potential to reduce environmental burdens and enhance food security, empirical evidence on the environmental and economic performance of IAS, particularly under real-world conditions and across spatial scales still remains limited. This thesis addresses critical knowledge gaps by employing a multi-scalar, method-integrated framework to assess IAS sustainability in the Chinese context, encompassing facility-level impacts, regional system modelling, and global supply chain dynamics.

The first study conducts a detailed life cycle assessment (LCA) of a commercial IAS facility in Chongqing, identifying fish feed and electricity as primary environmental hotspots and evaluating optimization strategies such as feed substitution and renewable energy integration. The second study extends the analysis to a regional level, developing a hybrid LCA–input/output (I/O) model to simulate the adoption of IAS across ten southern Chinese provinces. This system-level modelling, incorporating 1,920 climate–socioeconomic scenarios, reveals that carbon mitigation and economic co-benefits vary significantly depending on local energy mixes and climatic conditions. The third study applies a multi-regional input–output (MRIO) model coupled with LCA to examine the embodied carbon emissions in imported fishmeal and soybean feed. Results indicate that trade-origin optimization sourcing from low-intensity regions can substantially reduce upstream emissions with minimal economic trade-offs.

Together, these studies provide a comprehensive, evidence-based understanding of IAS sustainability under varying operational, geographic, and trade contexts. The integrated multi-scalar methodological framework was adopted because IAS sustainability cannot be adequately assessed at a single analytical scale: process-based LCA captures facility-level environmental hotspots, hybrid LCA–I/O modelling evaluates regional deployment effects under different climate and energy conditions, and MRIO–LCA traces upstream emissions embedded in global feed supply chains. By combining these complementary approaches, the thesis links operational performance, regional system transitions, and international trade dependencies within a coherent sustainability assessment framework. The findings highlight the importance of localized deployment strategies, carbon-informed procurement policies, and integrated assessment tools to guide sustainable aquaponics transitions in China. This thesis contributes empirically by providing one of the first operational datasets for industrial aquaponics systems in China, methodologically by integrating facility-, regional-, and trade-scale sustainability assessment approaches, and practically by identifying region-specific and supply-chain-oriented decarbonization strategies for sustainable food system transitions.