Research published in the online open access journal BMC Public Health show that Nile tilapia (Oreochromis niloticus) can be a valuable aid in the fight against mosquitoes; the animal responsible for transmitting malaria to humans. Today, malaria can be fairly easily treated and even cured, but a millions of people living in developing countries do not have access to malaria medication.

The emerging threat of pesticide resistance, and the fear of how poisons affect the rest of the ecosystem, has caused a comeback for the interest in biological mosquito control methods. The Nile tilapia’s fondness of mosquitoes has been known since the early 1900s, but the advent of powerful insect poisons during the 20th century steered research away from biological control and into chemical solutions.

After receiving funding from the Government of Finland, the BioVision Foundation in Switzerland and the Toyota Environment Foundation, researchers Annabel Howard and Francois Omlin from the International Centre of Insect Physiology and Ecology in Nairobi, Kenya, introduced Nile tilapia (Oreochromis niloticus L.) to abandoned fishponds in the Kisii Central District. Located in western Kenya, the Kisii Central District has over 2000 pediatric malaria cases per annum.

After 15 weeks of monitoring pond life and comparing the restocked ponds with a control pond nearby, Howard and Omlin could show that the tilapias had reduced the region’s primary malaria vectors, the mosquitoes Anopheles gambiae s.l. and Anopheles funestus, by over 94 percent. Mosquitoes from the genus Culex were simultaneously reduced by 75 percent.

“O. niloticus fish were so effective in reducing immature mosquito populations that there is likely to be a noticeable effect on the adult mosquito population in the area,” Howard says.

Nile tilapia thrives in the Kenyan climate and fish once added to a pond will find its own food and readily reproduce; thus providing a sustainable solution to the problem with mosquito. Nile tilapia is also a popular food fish in Kenya so a pond risking becoming over-populated with tilapia just needs a visit from some hungry anglers to be back on the right track again.