Understanding dried marine small fish losses in the regional supply chain of Tanzania

Despite previous research on small fish (Dagaa) postharvest losses, a comprehensive assessment of the entire regional supply chain remains limited. The study aimed to quantify Dagaa losses, identify their causes and propose mitigation strategies. Using FAO’s load tracking method, Informal Fish Loss Assessment Method (IFLAM) and Questionnaire Loss Assessment Method (QLAM), we monitored changes in product weight, quality and nutritional profile. Results highlight processing and transportation as the most critical loss points. Processing stage accounted for 19.5%, 10% and 0.18 USD kg− 1 quality, physical and monetary loss, respectively primarily due to animal predation, poor drying infrastructure, and over-boiling. Losses increase during the rainy season due to reliance on sun drying. Transportation losses were significant (6%, 8% and 0.89 USD kg− 1 quality, physical and financial loss, respectively) caused by overloading, compression and mishandling. Landing delays during bargaining contributed to 2% quality loss, while storage and packaging quality losses were 4% and 3%, respectively, due to poor storage conditions and overstuffing practices. At the marketing stage, quality and physical losses reached 4% and 5%, respectively, owing to inappropriate storage infrastructure and mishandling. Consumption stage recorded 0.1% physical loss. Protein content of dried fish significantly declined following storage and transportation (P < 0.05). The micronutrients levels remained stable post storage and transportation. Mafia Island Fisheries lose about 15 million USD annually. A multidimensional intervention approach is recommended to reduce post-harvest losses. The study offers insights to guide government policies on food security and postharvest management, while supporting industry efforts to enhance efficiency, profitability and sustainability.