Abstract
Industrial aquaponics systems (IAS) integrate aquaculture and hydroponics in a closed-loop design, offering a promising solution to sustainable protein production. However, their environmental performance remains insufficiently quantified, particularly in China. This study presents one of the first life cycle assessments (LCAs) of a large-scale IAS in Chongqing, based on operational data from a smart facility producing ~114,700 kg of largemouth bass and ~86,500 kg of vegetables annually. The analysis adopts a cradle-to-gate scope with a functional unit of 1 kg of marketable fish and employs the CML-IA method to assess ten midpoint impact categories. Results indicate that fish feed and electricity consumption are the dominant contributors to environmental burdens, particularly in global warming potential, eutrophication, and human toxicity. Scenario and sensitivity analyses reveal that reducing fishmeal content in feed and switching from coal-based electricity to renewable sources can significantly lower impacts. Comparisons with conventional protein sources demonstrate that aquaponics fish outperform pork and beef in most environmental categories when impacts are normalized by nutritional value. This study highlights key environmental hotspots and proposes viable optimization strategies, offering practical insights into the design and operation of climate-smart aquaponics systems. The findings provide a science-based reference for policymakers and practitioners aiming to promote resource-efficient food systems in urban China.