An innovative biocontrol initiative has been launched at the Mwea Irrigation Scheme in central Kenya, where golden apple snails have ravaged rice yields and heightened health risks for local communities. The project, undertaken by scientists from the Kenya Medical Research Institute (Kemri) in partnership with Israel’s Ministry of Agriculture, is testing the use of freshwater prawns as natural predators of the invasive mollusks. If proven effective, the intervention is expected to provide a model for other African nations grappling with similar agricultural and ecological challenges.
Mwea, Kenya’s largest rice-growing scheme covering more than 30,000 acres, has been under siege since the snails were first reported in 2020. Farmers have been forced to contend with destroyed seedlings, declining harvests, and escalating costs of chemical treatments. A peer-reviewed study published by CABI Agriculture and BioScience in 2024 showed that 80 percent of the paddies had already been infested, with most traditional management strategies yielding little success. Chemical applications, locally known as “duduz,” have been relied on heavily but have created concerns about water contamination and health impacts, while manual collection has been time-consuming, laborious, and often ineffective.
The new approach seeks to address two interconnected issues with a single intervention. Freshwater prawns, already documented as voracious predators of aquatic snails, are being introduced into targeted sections of the irrigation scheme. By feeding on the golden apple snails, the prawns are expected to suppress their population and, at the same time, lower the prevalence of bilharzia, a parasitic disease that depends on snail hosts for its transmission cycle. Bilharzia has remained one of the region’s most persistent waterborne health burdens, with reinfection rates remaining high despite decades of drug administration programs.
The prawns are being reared in controlled hatcheries and deployed in monosex populations to prevent unintended ecological effects. Scientists have stressed that the intervention does not involve genetically modified organisms, that the prawns are safe for human consumption, and that local aquaculture farmers may eventually play a role in rearing them. This integration of agriculture, aquaculture, and public health represents a strategic shift from reactive pest control to systemic ecological management.
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The challenge of invasive species in African agriculture is not unique to Mwea. Across the continent, farming communities have been forced to confront ecological disruptions that threaten both food security and health. In West Africa, rice growers in Nigeria have battled invasive weedy rice strains that cut productivity, while irrigation-linked schistosomiasis continues to affect rural populations in Ghana and Côte d’Ivoire. In southern Africa, the Lake Chilwa basin in Malawi has faced ecological strain from invasive mollusks, creating knock-on effects for fisheries and community livelihoods. These examples underline the broader significance of Kenya’s pilot, which is being closely watched as a possible model for adaptation elsewhere.
The implications extend well beyond the immediate challenge of pest control. If integrated into national agricultural strategies, biocontrol solutions such as the prawn intervention could help reduce reliance on agrochemicals, improve soil and water quality, and create complementary income streams for farmers through aquaculture markets. In Mwea, where household incomes have been directly affected by falling yields, the possibility of prawn farming offers an added layer of resilience. Furthermore, the reduction of bilharzia cases would free households from recurring healthcare burdens, improving productivity across farming communities.
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Regional coordination is expected to be essential. Irrigation schemes in Ahero, Bura, and West Kano, though not yet affected, have been identified as vulnerable due to frequent transfer of farm machinery and seedlings from Mwea. Without preventive action, the risk of spread remains high. For this reason, the pilot project has been framed not only as a local response but also as a continental case study in preventing ecological invasions from escalating into regional crises.
The initiative also highlights the importance of international collaboration in addressing Africa’s sustainability challenges. While Kemri scientists have contributed expertise in parasitology and local disease ecology, Israeli researchers have brought extensive experience in aquaculture and biocontrol systems. This exchange of knowledge and technology underscores how transnational partnerships can accelerate the testing of innovative solutions that neither side could achieve alone.
The future of the prawn solution will depend on sustained monitoring and integration into Kenya’s agricultural and public health frameworks. Scientists have emphasized that while drug-based interventions against bilharzia will remain necessary, the ecological approach can dramatically reduce reinfection rates by targeting the parasite at its source. If proven successful, the biocontrol model could be scaled across irrigation zones in Africa, providing a rare example of how food security and health security can be addressed together.
The golden apple snail invasion in Mwea has exposed how vulnerable African food systems remain to biological shocks. However, it has also revealed the potential of nature-based solutions to offer alternatives to chemical dependency. For African governments and regional bodies, the Mwea project may provide a turning point, one in which ecological innovation, international cooperation, and local resilience converge to confront the dual challenges of sustaining crops and safeguarding public health.
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