Urban aquaponics: A sustainable solution for food security and environmental conservation

In an era of growing urbanization and increasing food insecurity, a new study published in Engineering offers a promising solution through the innovative use of urban aquaponics. The research, titled "Shaping Resilient Edible Cities: Innovative Aquaponics for Sustainable Food–Water–Energy Nexus," explores how aquaponics—a system that integrates fish farming with soilless plant cultivation—can enhance urban food security while reducing environmental impacts.

The study, led by Qiuling Yuan and Fanxin Meng from Beijing Normal University, along with an international team of researchers, provides a comprehensive methodology and framework to assess the sustainability of aquaponics systems within urban jurisdictions. The research focuses on Beijing, China, as a case study to evaluate the potential of rooftop aquaponics (RA) and ground aquaponics (GA) in terms of water efficiency, energy consumption, and carbon emissions.

Aquaponics combines aquaculture (fish farming) with hydroponics (soilless plant cultivation) to create a symbiotic relationship between fish and vegetables. This system recirculates water from fish tanks to plant beds, where bacteria convert fish waste into nutrients for plants. The water is then returned to the fish tanks, creating a closed-loop system that minimizes water use and waste.

The researchers identified potential areas for urban aquaponics in Beijing by analyzing building types and sizes within the city's built-up areas. They found that commercial buildings offered the most potential for rooftop aquaponics, with an area of 3.4 km². Educational and industrial buildings also showed significant potential, covering 2.3 and 1.9 km², respectively. The study also considered ground aquaponics in suburban areas, where protected agricultural areas could be converted into aquaponics systems.

The life cycle assessment (LCA) conducted in the study revealed that both RA and GA systems consumed significantly less water than traditional greenhouses (TGs), saving 42%–44% of water during the on-farm stage. However, aquaponics systems required 2.3–3 times more energy and produced 1.1–2.1 times more carbon emissions than TG. Despite these higher energy demands, the "from farm to table" approach of aquaponics reduced energy, water, and carbon impacts by 14%–44% during the off-farm stage.

The study also explored the economic feasibility of urban aquaponics. While the initial costs of setting up aquaponics systems were higher than traditional agriculture, the economic benefits were substantial. The high selling prices of aquaponics products resulted in incomes 8–12 times higher than those from traditional greenhouses.

To optimize the sustainability of aquaponics systems, the researchers proposed various strategies, including the use of renewable energy sources, optimized fish feed, and improved material choices. These optimizations could reduce energy consumption and carbon emissions by 80%–85% during the on-farm stage. The study also highlighted the potential for urban aquaponics to increase local vegetable self-sufficiency by 15% and avoid 82% of the energy, water, and carbon footprints associated with upstream food supply chains.

The findings of this research underscore the potential of urban aquaponics to transform cities into self-sufficient “edible cities” with reduced environmental footprints. The study provides a generalizable framework for assessing and optimizing future agricultural modes, offering insights for urban stakeholders aiming to enhance agricultural sustainability.

The paper “Shaping Resilient Edible Cities: Innovative Aquaponics for Sustainable Food–Water–Energy Nexus,” is authored by Qiuling Yuan, Fanxin Meng, Yingxuan Liu, Jose A. Puppim de Oliveira, Lixiao Zhang, Wenting Cai, Zhifeng Yang. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.01.021. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.