As its name suggests, cage aquaculture involves raising fish in a net cage. The number of cages grew from nine in 2006 to more than 20,000 in 2019, according to a study published in Nature Food. In East Africa, between 2017 and 2021, the industry tripled in size, according to a report by Gatsby Africa. Yalelo Zambia is the biggest tilapia producer in Sub-Saharan Africa, producing 25,000 tonnes of fish combined at its facilities on Lake Kariba in Zambia and on the Ugandan side of Lake Victoria. Victory Farms, which is Kenya’s biggest producer of caged fish, also collects a lot of data. It developed a mobile incubation system, which keeps the eggs in motion in oxygenated water. The technology emerged from a project to construct brood stock ponds on plots in the nearby community. In return participants are paid for the harvested fish eggs, which are then transported to Victory Farms own ponds. Such innovations are beyond reach of the growing number of small-holder farmers who have ventured into cage fish farming.