Earlier this week, I saw an aquaponics system at a public school's rooftop garden: tilapia live in a tank below the garden, eat worms from the compost pile, and fertilize the plants. Small-scale farmers across the country are getting hip to the aquaponics system, too, and Epicurious has a great interview with the project manager of a planned aquaponics farm in Youngstown, Ohio. Unlike the Manhattan set-up, which uses the fish as little fertilizer factories to grow plants, the Youngstown operation is aiming to grow and eat the tilapia itself.