Thought up by Italian architecture firm Studiomobile, vertical seawater farms sticking up out of the water could covert the salt-laden liquid into freshwater for crops. It's all about producing humidity. A series of vents would gather humidity from the seawater to cool the greenhouses and, as it collects, irrigate the crops inside.
Studiomobile designed the farms with places such as Dubai in mind, where freshwater is scarce and the cost to transport fresh produce is high. With a vertical farm off the coast instead, produce would be grown locally, without straining the available resources. And, hey, maybe toss some old subway cars at the bottom of this thing and the fish won't mind it, either.