Fish farming is described as the process of raising fish in a controlled environment for commercial purposes. This form of aquaculture helps to provide a sustainable food source for humans and plays a role in keeping the oceans healthy.
Fish Farming Versus Fish Hatchery?
A fish farm is similar to a fish hatchery in the sense that they both contain fish. However, a slight difference exists. A fish hatchery is designed to raise fish only to a young age before they are released into a main farm. Usually, with fish hatcheries, the intention is to bolster the numbers of that species. In contrast, a fish farm is designed to raise fish to a size and age that makes them the best commercial value. Different types of fish farms utilize different methods. Below are some of the common methods.
The pond system is believed to be the oldest method of fish farming. Ponds enclose fish in a relatively shallow and usually small body of water. They vary from simple, low-tech extensive ponds to sophisticated hyper-intensive ponds. Ponds are self-contained and can be used for different types of fish at once. This makes them an optimal choice for most farmers.
Ponds need to be handled properly to realize their numerous advantages. If water is discharged without treatment or screening, it can impact the surrounding environment or allow the fish to escape. However, closed systems, where water is treated and used for multiple production cycles, reduce the risk of escapes and pollution. Species such as shrimp, catfish, and tilapia are commonly raised in ponds.
Pens: Pens are structures that hold farmed fish in open water as they grow. They’re made with wooden, mesh, or net screens. Many fish farmers prefer net pens because of their flexibility, versatility, and scale. They are designed to allow water to flow freely through them, which helps farmers deal with waste. Also, floating fish feeds stay within the enclosures. Net pens can be fixed in marine waters to farm species such as salmon and trout. Alternatively, they can be used in freshwater to farm species such as tilapia. Submersible net pens are fully enclosed and submerged, usually in offshore marine waters.
The raceway system is another method used in fish farming. Raceways consist of long, linear containment structures which are relatively shallow and terraced above the ground. Raceways rely on a high-water flow in proportion to their volume to sustain aquatic life. A typical raceway production system consists of a tank (rearing unit) or a series of rectangular tanks with water flowing along the long axis. For successful fish farming, the inflowing water must be within the temperature tolerance of the species being raised. Oxygen is provided by the incoming water and is removed by the fish as the water progresses down the raceway.
In most raceway systems, dissolved oxygen is replenished by allowing the water to fall into subsequent tanks within the raceway. Raceways can be used both indoors and outdoors. Treating wastewater can generally minimize the contamination of waterways and the spreading of diseases to wild fish. Species such as tilapia and rainbow trout can be farmed in raceways.
Re-circulating tanks: As the name suggests, this system has continuous water flow, and the wastewater is treated and reused. Fish stocks are reared in a series of interconnected, fully controlled tanks that are indoors and have virtually no chance of contact with wild stocks. In this system, the closed circuit of pipes carries clean water to the tanks, while wastewater is pumped out of them, purified, and then recirculated. By circulating the water in the fish tank in this way, the water and energy requirements can be kept to a minimum. Since the water used for fish farming is treated and reused, only a small amount of water has to be added.
The re-circulating tank system is set above the ground and can be employed in a variety of locations to avoid sensitive habitats. They can also minimize or avoid the discharge of pollutants beyond the farms. The potential for disease and parasite transfer to the natural environment is low, and the escape of farmed fish can be prevented. Fish species such as Arctic char, striped bass, and sturgeon can be raised in land-based, re-circulating tanks.
Fish farming is one of the most reasonable agricultural ideas where income is made consistently. Again, the high consumption of fish and fish products makes fish farming an attractive venture worldwide.
Information from https://thehealthyfish.com/4-common-methods-aquaculture/, https://freshwateraquaculture.extension.org/raceways/,https://www.encyclopedia.com/environment/energy-government-and-defense-magazines/fish-farming, https://m.farms.com/farming/fish-farms.aspx, https://onyxaqua.com/2022/01/03/recirculating-aqua-culture-how-does-work-ras-fish-farming/, and https://www.seafoodwatch.org/seafood-basics/fishing-and-farming-methods