Farming an Invasive Species: Challenges and Benefits of Rapidly Expanding Cage Aquaculture in Lake Victoria

In the face of stagnating wild fisheries in Lake Victoria and a rapidly growing human population, aquaculture may improve food and livelihood security in Kenya, Uganda, and Tanzania. Decades ago, an introduced species of tilapia took over the niche of an indigenous species of tilapia that was severely overfished. Very recently, cages for farming the introduced species have been popping up on the lake at an alarming rate. While cage culture could provide food and income, there are many pressing questions: what will be the physical impact of cages on the lake’s limnology? Will there be adverse effects for wild populations? Will farmed tilapia become a significant export commodity and, if so, will this create food insecurity around the lake? The coupled human and natural system explored here links human food security and wild fisheries through physical and economic changes brought about by escalating cage aquaculture. In an interesting twist, farming the near-extirpated indigenous tilapia could provide a hedge against climate threats to cages of introduced tilapia. Here, we explore the demand and supply forces that are encouraging rapid cage culture in Lake Victoria, the potential impacts on lake ecology, and the risk and benefits posed for human food security.