Integrating Coastal Agriculture and Mariculture for Food and Nutritional Security in Africa: Comparative Insights from Selected African Case Studies

Africa’s coastal regions face severe food and nutritional insecurity, with over 295 million people globally affected by acute hunger, a significant portion in Africa, and over half of children in Eastern and Southern Africa experiencing micronutrient deficiencies, exacerbated by climate-driven stressors like sea-level rise, salinisation, and extreme weather. This chapter explores the transformative potential of integrating coastal agriculture and mariculture to enhance food and nutritional security in African coastal communities, focusing on practical applications and Namibia’s untapped opportunities. Drawing on ecological frameworks such as Integrated Multi-Trophic Aquaculture (IMTA) and circular economy principles, it examines case studies from Ghana, Senegal, Morocco, Tanzania, Nigeria, Kenya, and Madagascar, alongside Namibia’s implementation potential. In Ghana, shellfish-crop polycultures in the Volta Delta increased dietary diversity by 25%, addressing stunting in 17.5% of children under five while reducing nutrient runoff by 40%. Senegal’s rice-fish systems in the Saloum Delta boosted yields by 20% and cut pesticide use. Morocco’s seaweed-vegetable integration produces over 500 tons of shellfish annually, using seaweed as biofertiliser to combat coastal poverty. Tanzania’s shrimp-mangrove systems aid 35% of food-insecure households. Nigeria’s fish-crop systems combat 40% post-harvest losses. Kenya’s seaweed-fish-crop systems benefit 30% of insecure coastal households. Madagascar’s rice-fish systems enhance productivity by 19–31%. In Namibia, where 57% of food is imported (95% for fruits) and coastal agriculture is constrained by salinisation, integrating mariculture with salt-tolerant crops could leverage the Benguela Current, creating employment to address 36.9% unemployment and reduce dependency. Challenges include limited training, high costs, policy gaps, permit delays, and climate risks exposing 108–116 million Africans to sea-level rise by 2030. Proposed strategies encompass capacity building via the Asia-Africa BlueTech Superhighway, microfinance, streamlined licensing, and mangrove restoration. Integrated systems offer a sustainable pathway to SDG 2 and SDG 14, fostering food sovereignty.