This chapter discusses aquaculture for nutrition security, which raises questions such as, do we need fish? Can we supply sufficient seafood for future populations? Can we do so in a responsible manner? Aquaculture is animal seafood production. While only 2 percent of the total human food comes from fish, 17 percent of animal protein production comes from seafood. In the late 20th century, the world witnessed a strong industrialization of capture fisheries, but now we have reached our maximum for capture fisheries. Aquaculture makes up the difference to keep up with demand for fish. There are about 600 species produced in aquaculture in a wide variety of production systems. The first on his the equivalent of grassland in which the animals grow basically on natural food produced in the system around them, basically reliant on photosynthesis and primary production. To increase production, external feeds are necessary, and the environment becomes a holding tank. If the water is reused and purified it is a recirculating aquaculture system. Fish are poikilothermic animals and don’t need to carry their own weight, and therefore don’t need a lot of energy to maintain body functions. Fish are often point-fed fish, which is a very controversial issue. There is a laser waste problem and also an issue with the possibility of escapes of fish from the farm into the natural environment. Since fish are mostly fat they absorb many chemicals and can be a source of pollution in the environment. Two problems that aquaculture faces are replacing fish meal and fish oil as feed, which has seen significant improvement with plant ingredient and soya. The recycling of this water and the use of bacterial biomass that has been growing on waste materials are areas of great research in this field so that environmental impact is internalized in the farm. Innovation is necessary; combining fish production with horticulture, in the way of aquaponics, or in an integrated system maximize efficiency is a way to do aquaculture in a sustainable way. Fish is perishable, and so cannot be farmed far from urban centers, so must be intensively farmed in capture fisheries on small plots of land. We have to have intensive and efficient production focused on novel feeds, selective breeding, and health management.