Commercial aquaculture ponds have special design requirements for each particular species of fish or shrimp. In general, aquaculture ponds are shallow and drainable. While it is possible to use existing bodies of water that cannot be drained, for example by using floating net cages, it is usually best to remove competing species and to ensure a population of uniform size in the culture species.
Typically, smaller ponds of ¼ acre to 1 acre in size are easier to manage although more costly to construct than larger ponds on a per acre basis. Similar to agricultural fields, it is best to clear the area before planting the desired species. For hatchery ponds where fish eggs or fry will be introduced, removal of predatory insects and other aquatic organisms, including fish, is critical to ensure the survival of most of the young fish.
The shape of the pond also is important for efficient harvesting and usually the bottom is sloped to one end where a catch basin is typically installed for ease of harvest. Rectangular shapes are preferred when long seines are used to harvest the fish without draining the pond. In the case of shrimp ponds, however, narrow rectangular ponds are needed to ensure uniform feeding across the entire surface since the shrimp do not move around like fish do at feeding time. Shrimp ponds are often only two to four feet deep. At harvest, shrimp cannot be seined and must be removed by draining the pond. In fish ponds that are drainable, the shape is less important since fish readily learn to come to feed at whatever location the farmer uses on a regular basis. Fish rearing ponds are only four to six feet deep, shallow enough for ease of aeration and deep enough for temperature stabilization during the growing season.
It is also important to consider access roads adjacent to the ponds for feeding and harvesting. Adequate free board or height of road surface above the water level depends on the soil type, but is usually two to three feet or more. More free board increases road stability but less height improves the ease of harvest when nets of fish have to be removed from the catch basin in the drained pond.
Beyond the shape of the ponds, other major considerations in pond design are related to water supplies, electrical service and aeration networks. The facilities that are designed for commercial aquaculture are customized for particular sites with these needs in mind.