Nutrient composition of common fish species in the Okavango Delta: potential contribution to nutrition security

Fish can be a key strategy in addressing the global food and nutrition insecurity challenges. Fish nutrient data are critical for policy development targeting to reduce these problems. Despite this, much of the published studies on nutritional characteristics of fish have focused on marine ecology and there is little information on natural freshwater fish habitats like inland delta areas. This study investigated the nutrient composition of Okavango Delta fishes and their potential contribution to the recommended nutrient intake. Fish species sampled were Clarias ngamensis, Oreochromis andersonii, Schilbe intermedius, Marcusenius altisambesi, Brycinus lateralis, Barbus poechii and Tilapia sparrmanii. The nutrients analyzed were moisture, ash, proteins, Na, K, Ca, Mg, P and Zn. The small fishes (B. lateralis and B. poechii) had higher mineral content; Ca (643–968 mg/100 g), Mg (47–49 mg/100 g) and Zn (2.8–3.6 mg/100 g) compared to the larger species with average mineral content; Ca (73–460 mg/100 g), Mg (23–35 mg/100 g), Zn (1.2–2.9 mg/100 g). The most nutrient-dense species recognized were B. poechii and B. lateralis followed by the large species, M. altisambesi. These species illustrated the potential to contribute 80–121% Ca, 32–47% Mg and 70–150% Zn of the recommended nutrient intake to children (1–9 years), pregnant women and the elderly (65 + years). The study recommends prioritizing small and some large species (M. altisambesi and T. sparrmanii) for polyculture systems, primarily for securing food and nutrition security for local communities.