In Kenya’s arid regions, a new approach to aquaculture is taking shape: high‑rise fish farms that mimic the natural ecosystem of a lake. Inventor Jack Oyugi’s vertical system houses 10,000 tilapia in stacked tanks, recycling up to 95% of the water and running entirely on solar power. Fish waste is turned into organic fertilizer, which local farmers value as a sustainable alternative to synthetic products. As demand for fish continues to exceed supply, this circular approach that features innovations like vertical aquaculture and recycled‑water pond systems is helping boost food security and create new income opportunities in dry areas.