Assessing the Productivity and Socioeconomic Viability of Rooftop Aquaponics Systems in a Dense Urban Core: A Year-Long Case Study of Toronto, Canada

Abstract

Urban land scarcity necessitates innovative vertical food production methods to enhance city resilience. This study provides a twelve-month evaluation of the productivity, resource efficiency, and socio-economic viability of a commercial-scale rooftop aquaponics system, “SkyGreens,” in downtown Toronto.

The study uses mixed methods, combining quantitative monitoring of agronomic outputs (lettuce, Lactuca sativa, and tilapia, Oreochromis niloticus) with qualitative analysis of market channels and operational challenges. The system produced 42 kg/m²/year of lettuce and 15 kg/m³/year of tilapia, with 90% higher water-use efficiency but 260% higher energy consumption than conventional agriculture.

Financially, the system achieved a 28% return on investment by Year 3 through premium restaurant sales. The study concludes that rooftop aquaponics is technically viable and environmentally sustainable within an Integrated Urban Food System (IUFS), though economic success depends on premium market positioning and supportive policy frameworks to offset high capital and energy costs.

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Introduction

Sustainably feeding growing urban populations amidst climate change and resource constraints is a central concern for 21st-century cities (FAO, 2020). Integrated Urban Food Systems (IUFS) propose a paradigm shift from linear food chains to interconnected, resilient networks that localize production, reduce food miles, and close nutrient loops.

Within this framework, Controlled Environment Agriculture (CEA) technologies like aquaponics—a symbiotic integration of aquaculture (fish farming) and hydroponics (soilless plant cultivation)—represent a promising frontier (Goddek et al., 2019). Aquaponics offers theoretical advantages for dense urban settings: it requires minimal land, reduces water use, and produces both plant and fish protein in a single system.