Aquaponics is an integrated system combining aquaculture and hydroponics that recycles fish waste into plant nutrients, enabling sustainable food production with minimal land and water (Rakocy et al. 2006; Somerville et al. 2014). In Uganda, rapid urbanization, climate stress, and shrinking farmland have undermined traditional agriculture and aquaculture (FAO 2020). Emerging pilot projects demonstrate promise, yet high startup costs and dependence on imported components limit aquaponics adoption (Okello et al. 2020). This study investigated small-scale system built from locally available materials, assesses their costs, and market potential for fish and vegetables.
Methods: A model unit was assembled using a 1000 L plastic tank, 200 L drum reservoir, PVC piping, gravel and bottle-cap media, and lettuce (Lactuca sativa) seedlings. Nile tilapia (Oreochromis niloticus) fingerlings were stocked at 20 kg/m³ and fed daily. Water quality (NH₄⁺, NO₃⁻, pH, DO) was monitored over 30 days using standardized methods (Danner et al. 2019).
Results: Biofilter media setups reduced NH₄⁺ from 0.8 ± 0.1 to 0.1 ± 0.02 mg/L within 7 days, while NO₃⁻ increased from 2.5 ± 0.3 to 10.2 ± 1.1 mg/L. Lettuce biomass increased by 98% (wet weight), and fish survival exceeded 90%. Cost benefit analysis showed payback in six months at existing market prices (Rakocy et al. 2006).
Market surveys in Kampala showed that fish could be bought at UgX 12,000–15,000/kg and lettuce at UgX 800–1,200/head.
Local innovations and community training have fostered adoption among youth and women especially in urban areas. With policy support and capacity building, aquaponics can enhance Uganda’s urban food security and livelihoods.
Keywords: Aquaponics, Uganda, locally available materials, fish market, urban farming
References:
Danner R, Mankasingh U, Anamthawat-Jonsson K, Thorarinsdottir R. 2019. Designing Aquaponic Production Systems. Water 11(10):2123.
FAO. 2020. The State of World Fisheries and Aquaculture 2020. Rome: FAO.
Okello D, Wambede S, Sekabira H. 2020. Innovation adoption in integrated fish-vegetable systems in Uganda. Uganda J Agric Sci 21(1):15–24.
Rakocy JE, Masser MP, Losordo TM. 2006. Recirculating aquaculture tank production systems: Aquaponics—Integrating fish and plant culture. SRAC Publ No. 454.