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.