Freshwater aquaculture refers to the farming of freshwater plants and animals. Many types of fish, invertebrates and plants are grown in freshwater aquaculture systems around the world. Though the majority of these systems are used to grow food, there are type of freshwater aquaculture farms that specialize in raising the ornamental fish and plants kept in aquariums and ponds.
There are three systems generally used in freshwater aquaculture. In the pond system, which is the simplest to set up and maintain, farmers stock young fish in existing or man-made ponds. Alternatively, a cage system can be installed in a natural body of water that is too large for easy harvesting. Technological developments have also made it possible for farmers to take control of the aquatic environment by using a recirculating system. This system allows for large-scale, year-round production but requires a large initial investment.
Tilapia, which grows quickly and is a relatively hardy fish, is frequently raised in ponds, though it does well in any aquaculture system. With its mild flavor and high protein content, tilapia is a popular food fish around the world. The fish breeds readily and eats almost anything, which makes it easy to farm. In some parts of the world, tilapia are even grown in rice paddies, saving space and giving many rural communities an extra source of protein and income. Crustaceans, including crayfish and shrimp, can be raised in rice paddies alongside tilapia.
Another type of fish that is commonly farmed is trout. Requiring more precise conditions than tilapia, trout are often raised in recirculating aquaculture systems. Farmed trout are commonly used to stock lakes, streams and reservoirs so that people can fish for them. Trout farms also sell fresh fish to grocery stores and markets.
Ornamental fish, from goldfish to cichlids, are bred and raised through the use of freshwater aquaculture. Utilizing the same principles as larger recirculating systems, breeders of exotic fish must control every aspect of the aquatic environment if less-hardy species are to thrive. Breeders of aquarium fish provide fish for the pet trade.
Plants can also be grown in freshwater aquaculture systems. Aquarium and pond plants, such as lotus or water lilies, are often cultivated in ponds or tanks. Additionally, many island communities have begun to use aquaponic technologies, which allow for freshwater fish and plants to be grown in a symbiotic system. In aquaponics, the waste created by fish, often tilapia or catfish, provides the nutrients needed to grow lettuce or other plants that can be eaten or sold.