Rice farmers in Senegal have struggled for years with three problems. Some suffer from a snail-borne disease called schistosomiasis. Many lack protein in their diets. And they often lack enough fertilizer for their crops. Plans meant to address each issue have failed to succeed. That’s where a research team led by Momy Seck Ndao came in. The team proposed a single fix for all three issues. Just add fish, the team said. “We integrated native Nile tilapia (Oreochromis niloticus) and African bonytongue (Heterotis niloticus) into rice fields,” the team wrote in a study published recently in the journal Nature Sustainability. “The fish thrived, suppressed insects and snail pests, improved soil nutrients and boosted rice yields by >25%.” First, the disease. Rice is grown in shallow ponds called paddies. Freshwater snails thrive in rice paddies. But they also carry the parasites that cause schistosomiasis. It's a painful disease that results in rashes, fevers, and kidney or liver damage. African bonytongues like to eat snails. They can eat thousands of them. And fewer snails means a lower risk for schistosomiasis. All that water in rice paddies can also support tilapia. It's one of the most commonly-eaten fish species in the world. After the team introduced tilapia to the rice paddies, the fish population boomed. Tilapia have no natural predators in the rice paddies. Their numbers swelled. The large number of fish produce a lot of poop. It is a perfect fertilizer for rice. As a bonus, the rice farmers have a sustainable source of easily-caught meat. Ndao’s team has added the fish to only a few rice farms. Results have been so positive, though, that she hopes to expand the program up and down the Nile River in the near future. Reflect: What's one small fix that could solve more than one problem at once? Photo of combined cultivation of rice and tilapia fish aquaculture in a paddy field from Wikimedia Commons courtesy of Kembangraps.
