Tilapia might not be best solution for Africa's smallholder farms, study finds

A new study authored by scientists from the University of Stirling's Institute of Aquaculture and WorldFish has found pond polyculture can serve as an important supplement to capture fisheries  in areas subjected to seasonal fishing restrictions.

The paper, published in the scientific journal Foods, was titled "The role of aquaculture and capture fisheries in meeting food and nutrition security: Testing a nutrition-sensitive pond polyculture intervention in rural Zambia."

The study focused on Zambian smallholder homesteads, finding that those that stocked various indegenous, micronutrient-rich small fish species instead of relying tilapia canoffer a direct source of food for household consumption, rather producing a monoculture strictly as a cash crop.

WorldFish Global Lead for Nutrition and Public Health Shakuntala Haraksingh Thilsted, one of the study's coauthors, 

"Aquaculture, especially polyculture systems with indigenous small fish species, has the potential to improve the nutrient intake of households during closed fishing seasons," Thilsted said. "Fisheries management regulations, introduced by the Zambian government to overcome overfishing, ban the capture or sale of wild fish between December and February every year. However, these measures drastically reduce the consumption of fish during these months, leading to lower intakes of key nutrients and essential fatty acids. This is especially pertinent for people living in parts of Zambia where fish is their primary source of animal protein."

University of Stirling doctoral candidate Alexander Kaminski, the study's lead author, said the study found a polyculture approach could help preserve natural resources while at the same time providing better nutrition to local smallholder farmers.

“Polyculture ponds provide a good source of diverse, micronutrient-rich small fish species. However, the amount of fish from the wild, especially small fish species from the large lakes that are dried, play a more significant role in people’s nutrient intake," Kaminski said. "Ultimately, any improvements to aquaculture should not be done in isolation without considering the more-important role of capture fisheries in providing cheap, micronutrient-rich small fish for vulnerable people.” 

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