Aquaculture exemplifies the ongoing global struggle to strike a sustainable balance between the conflicting needs of a rapidly increasing world population, human health, ecosystem health, the welfare of wild and domesticated animals, and the economic principles of globalized economies. On the one hand, aquaculture has great potential for providing us with a healthy and nutritious food supply whilst alleviating pressure on captive fisheries and reducing fisheries-induced habitat destruction, overfishing, genetic modification of wild populations, and wholesale waste of bycatch. On the other hand, aquaculture relies heavily on clean water, an increasingly precious (and dwindling) resource that is subject to intense pressure of being used for many competing objectives. This concise primer introduces students to the basic concepts, opportunities, and challenges of aquaculture with an emphasis on ecological considerations. It provides a critical assessment of current aquaculture practices fr