In the middle of a muddy field next to a reservoir in north-western Malawi, a team of scientists are hard at work. Boxes of equipment lie scattered around a patch of dry ground, where a scientist programmes an automated drone flight into a laptop perched on a metal box. The craggy peak of Linga Mountain (‘watch from afar’ in the local language) looms over the lake, casting its reflection in the water.
With a high-pitched whirr of rotor blades, the drone takes off and starts following the shoreline, taking photos as it goes. Once the drone is airborne, the team switch from high-tech to low-tech mode. They collect ladles, rulers and plastic containers and squelch through mud until they reach the water’s edge.
The scientists measure the water depth with a ruler and carefully ladle water into the containers. Using a mobile app, they record the GPS location of each sample. Back on dry ground, they count the number of mosquito larvae in each container.
Malaria is one of the top three causes of death among children under five years old in Malawi.
A team from Liverpool School of Tropical Medicine and Lancaster University have been doing the same thing for two weeks at five reservoirs in Kasungu. They are collecting data to identify mosquito breeding sites, so that the larvae can be controlled, reducing the number of adult mosquitoes able to spread malaria.
“We stitch together the drone photos to create an aerial map of the reservoir,” says Michelle Stanton, one of the scientists on the team. “Our water samples tell us where the mosquito breeding sites are, and we can plot these on the map... We can [then] identify the common features of these sites and predict where other breeding sites are.”