The status of recirculating aquaculture systems in Africa: A review

Abstract

Recirculating Aquaculture Systems (RAS) present a promising and sustainable approach to addressing Africa’s aquaculture challenges by significantly reducing water consumption, minimizing land use, and mitigating environmental impacts. However, despite their potential, RAS adoption across the continent remains limited due to high initial investment costs, technical complexity, and the absence of supportive policy frameworks. This review synthesizes the current landscape of RAS in Africa by examining technological adoption trends, environmental and economic implications, and the status of regulatory frameworks. Drawing on peer-reviewed literature, regional data, and case studies from leading countries such as Egypt, South Africa, and Nigeria, the study highlights that RAS currently accounts for less than 4.5% of aquaculture production. Notably, RAS systems significantly reduce water usage and enable nutrient recycling, although their high energy demands (15-20 kWh/kg fish) pose a sustainability challenge. RAS systems need steady electricity supply, which represent important limited factors in most of African countries. Economically, while the upfront production costs range between $0.50 and $1.00 per kilogram of fish, these are offset over time by enhanced biosecurity and productivity. The lack of RAS-specific regulations in most African countries remains a major barrier to wider adoption. The review underscores the need for regionally coordinated efforts in areas like integration of renewable energy solutions to enhance scalability. Summative, RAS success depends on targeted investments in context-appropriate technologies, capacity building, and policy harmonization to address persistent financial, political and technical constraints.