Technical Abstract: This book chapter summarizes aquaculture pond ecology. The underlying theme is how ponds supply essential life-support functions (food, oxygen, and waste treatment) and how those functions are subsidized by external resources as culture intensity increases. Ponds are confined bodies of standing water where, by virtue of a long hydraulic residence time, suitable water quality for animal production is controlled primarily by natural physical, chemical, and biological processes that occur within the water body. The functionality of ponds as aquaculture systems is driven by solar energy, which regulates pond temperature and provides light for photosynthesis, which provides three essential support functions in aquaculture ponds: 1) food for cultured animals, 2) oxygen to support life, and 3) treatment of wastes so that they do not accumulate to toxic levels. Sunlight energy has a fixed maximum that limits the capacity of a pond ecosystem to provide these essential life-support functions. These limitations progressively shift from supplying sufficient food to supplying sufficient oxygen to removal of nitrogenous waste products as culturists try to achieve progressively greater crop yields. Overcoming each limiting factor requires energy input from outside the pond to supplement services dependent on incident sunlight. Those inputs may be in the form of solar energy fixed as organic matter in other ecosystems and then transferred to a pond or they may be direct inputs of industrial energy, mostly from fossil fuels. The theme of culture intensification and changing resource use is developed in sections describing pond water use, pond fertilization, use of processed feeds, oxygen budgets and aeration, waste treatment, land use, and the ecological footprint of pond aquaculture. Additional sections summarize the consequences of unregulated algal growth in ponds, practical constraints on production, comparative economics of aquaculture systems, and sustainability issues.