Circular Economy for Sustainable Animal Feed: Harnessing Sargassum Fluitans for Food Security and Coastal Restoration in Lagos State, Nigeria

Abstract

In response to growing global concerns over feed scarcity, rising production costs, and coastal degradation, this study explores the transformative potential of Sargassum fluitans within a circular economy framework. The research assessed the sustainability of using this nutrient-rich yet environmentally problematic seaweed as an alternative animal feed ingredient for chickens, fish, pigs, and rabbits in Lagos State, Nigeria. Despite its abundance, Sargassum remains underutilized due to the absence of effective Monitoring and Evaluation (M&E) frameworks that ensure project efficiency, economic feasibility, and long-term sustainability. Guided by Implementation Theory and Theory of Change, this study employed a mixed-methods approach. A 12-week randomized controlled trial was conducted to evaluate the nutritional performance, growth metrics, and survival rates of animals fed Sargassum-based diets. Feed safety was ensured through Hazard Analysis and Critical Control Points (HACCP), while Linear Programming Optimization (LPO) developed cost-effective feed formulations. Quantitative data were analyzed using ANOVA and t-tests; qualitative insights were supported by stakeholder engagement and Logical Framework Analysis (LFA). Findings revealed that Sargassum-based feed is nutritionally comparable to conventional feeds and significantly reduced feeding costs by 55.5%. It enhanced animal growth, improved food security, generated green jobs, and contributed to coastal restoration by reducing Sargassum waste buildup. By closing material loops and repurposing marine biomass, the study offers a replicable model for integrating marine resources into sustainable agriculture. The result-based M&E framework ensured accountability, informed decision-making, and scalability, aligning the project with SDGs 2 (Zero Hunger), 8 (Decent Work and Economic Growth), 12 (Responsible Consumption and Production), 13 (Climate Action), and 14 (Life Below Water). This research repositions Sargassum from an ecological burden to a blue economy asset, offering a novel, data-driven, and locally adaptable solution for sustainable livestock production in sub-Saharan Africa.