Technical Abstract: Conventional aquaculture ponds provide a number of ecological services supporting fish and shellfish production. The pond provides confinement space for the aquatic organisms, while algal growth in the pond serves as the base of an aquatic food chain providing some or all of the feed, depending on pond carrying capacity. In addition, algal growth removes potentially toxic carbon dioxide and ammonia from the pond and supplies oxygen. Other microbial, physical, and chemical processes assist in treatment of metabolic waste produced by the aquatic animals. In most ponds these functions occur simultaneously in the same space where the animals are cultured as they are allowed roam freely within the pond. The space required for animal confinement is much less than the area or volume needed to support the waste treatment functions. Consequently, combining animal-confinement and ecosystem support into the same physical space leads to inefficiencies and management difficulties. These inefficiencies are addressed in the Partitioned Aquaculture System (PAS), where the fish-confinement function is physically separated from ecological functions to provide greater control over fish populations and environmental conditions. This technique represents an adaptation of the “high-rate ponds” developed for treatment of municipal wastewater. The primary advantage provided by the high-rate pond and PAS is to increase algal production within the pond, accelerating ammonia assimilation and oxygen production. Channel catfish production in the PAS has exceeded 20,000 kg/ha. Subsequent developments of the PAS concept have concentrated on lower-cost modifications, including the Mississippi “Split-Pond,” the Alabama “In-Pond Raceway,” and the California “Pondway.” The goal of these modifications is to provide less control over pond ecology relative to the PAS, but at a lower cost.