Could fish be a secret ingredient for rice farmers to avoid disease and make more money?

Researchers net tilapia, which they'll transport to the paddies of a rice farm in the Senegal River Valley. Ricci Shyrock for NPR hide caption toggle caption Ricci Shyrock for NPR Momy Seck Ndao has been planning for this day for months. The environmental engineer is standing beside two swimming-pool sized ponds, each lined with a black tarp and full of hundreds of tilapia. Two of her colleagues trudge through the pond in waders, trying to corral the fish with a net. "For this project, we need a lot of tilapia, about 1,900," says Ndao, as she eyes the horizon. They're in a race against the rising sun. It's still relatively low but will soon heat this part of the Senegal River valley to about 100 F, hot enough to bake the fish on the way to their final destination — a rice field. There, these tilapia — and a handful of other fish — are the key ingredients in an ambitious experiment. Ndao and her colleagues are trying to see if adding fish to rice farms can help solve three problems plaguing rice farmers, and Senegal more broadly — food insecurity, poverty and a debilitating disease. To Ndao, it's a particularly Senegalese solution. The national dish, thieboudienne, is a delectable combo of rice and fish. "We eat it every day. So if you grow rice and fish in the same area, you just need to add vegetables," Ndao says with an easy laugh, "and you will have your daily dish." Fishing expedition But first, Ndao and her team have to catch those tilapia and schlep them to the farm. Once enough fish are concentrated by the net into a writhing mass, other colleagues swoop in with smaller buckets to scoop them up. Quickly, but careful not to spill, they shuttle the buckets to a big green tank on the bed of a pickup. The team is on a mission to scoop up nearly 2,000 tilapia at a fish farm in Dagana, Senegal. Ricci Shyrock for NPR hide caption toggle caption Ricci Shyrock for NPR It takes about an hour to load up the fish. Kayla Kauffmann, a Stanford disease ecologist on the project, rushed over to the truck just after the tank was sealed. "I wanted to look in before they closed it," she says. "It's quite the operation." Today's operation began before dawn and is far from over. On the outskirts of the coastal town of Saint Louis, the team — over a dozen scientists, aquaculture technicians and interns — set off in the dark. Before reaching the tilapia farm in Dagana, about 80 miles northeast across the vast expanse of the Sahel, some of the caravan peeled off to catch a few larger fish of a different species, which will be the main disease-fighters. Momy Seck Ndao, an environmental engineer who is part of the fish-rice project, wrangles an African bonytongue fish, also called heterotis, that escaped its bucket. The fish will soon be introduced to a rice farm, where researchers hope it'll eat snails that spread a debilitating disease called schistosomiasis. Ricci Shyrock for NPR hide caption toggle caption Ricci Shyrock for NPR The next and final stop, about 20 minutes away, is Keur Mbaye, where the fish will be introduced to a rice field. There, all those fish will live and poop, fertilizing the crop. It's one of 60 fields across the region where the team, in conjunction with local farmers, will be trying out this potential win-win-win solution. To Ndao, the stakes are high. "The potential is here," she says. "Everything will depend on what they will see in this experiment, what they will learn." Dangerous worms, protective fish Rice production is booming along the winding Senegal river, which forms the border with Mauritania to the north. The immense Sahara is just a hundred-some miles away. Historically, the semi-arid climate meant that farming could only happen during the rainy season. But dam construction starting in the 1980s helped supply a steadier stream of water for crops. Knee-deep in a Keur Mbaye rice field, Kauffman holds out in her gloved hand a tiny example of what else the dams allowed to flour