Opportunities and challenges for the sustainable valorization of fish processing byproducts in Ethiopia

Fish processing generates substantial quantities of by-products, including heads, frames, viscera, skin, scales, and trimmings, which may constitute between 30% and 70% of the total fish biomass. Although these materials contain valuable proteins, lipids, minerals, collagen, and other bioactive compounds, they remain largely underutilized in Ethiopia. This review aimed to assess the status of fish-processing by-products in Ethiopia, evaluate their potential for value addition and resource recovery, and identify the major opportunities and constraints affecting sustainable valorization.A comprehensive review of published scientific literature, technical reports, and fisheries-related documents was conducted to synthesize available evidence on fish-processing practices, by-product generation, composition, management and disposal practices, environmental impacts, and valorization opportunities. Particular attention was given to major commercial fish species in Ethiopia, including Nile tilapia ( Oreochromis niloticus ), African catfish ( Clarias gariepinus ), and Labeobarbus species from Lake Tana.The review indicates that fish-processing by-products in Ethiopia are predominantly disposed of or used in low-value applications despite their potential for resource recovery. The literature identifies fishmeal and fish oil, organic fertilizers, collagen and gelatin, protein hydrolysates, and other bio-based products as important valorization pathways. However, their utilization is constrained by inadequate processing infrastructure, limited cold-chain facilities, fragmented supply chains, insufficient technical capacity, weak market linkages, and limited policy and institutional support. Improper disposal of fish-processing residues can also contribute to environmental pollution, odor generation, public-health concerns, and loss of potentially recoverable resources. The synthesis further indicates that relatively established pathways, such as fishmeal, fish oil, and organic fertilizer production, provide more accessible entry points for valorization, whereas collagen, gelatin, protein hydrolysates, and other higher-value products require greater technological, quality-control, and market capacity.This review provides an integrated synthesis of fish-processing by-product valorization opportunities within the Ethiopian context and demonstrates that successful valorization requires more than the adoption of processing technologies. It requires coordinated improvements in by-product collection, preservation, processing, quality assurance, market development, technical capacity, and institutional support. A phased valorization strategy, beginning with relatively established and accessible applications and progressively expanding toward higher-value products, could reduce environmental impacts, improve resource efficiency, create additional economic opportunities, and support the transition toward a circular fisheries economy in Ethiopia.