Types of fish farming sytems and methods in India: Fish farming is a form of aquaculture process in which fish are raised in enclosures to be sold as food. Fish species raised by fish farms contain salmon, catfish, tilapia, cod, and others. Fish farming also called pisciculture. It is the process of nurturing organisms that inhabit water commercially in a controlled or semi-controlled environment to increase productivity.
A guide to types of fish farming methods
Fish farming is the primary form of aquaculture. Fish farming is the cultivation of fish for commercial purposes in man-made tanks and another type of enclosures. The common types of farmed fish are catfish, tilapia, salmon, carp, cod, and trout.
Mariculture
Mariculture is an activity mainly involving food production for human consumption. The mariculture process is the cultivation of marine organisms such as fish and shellfish for food. For example, Finfish (like flounder and whiting), shellfish (like prawns and oysters), and sea plants (like kelp and seaweed) are cultured in saltwater. Mariculture products are used for cosmetics, jewelry such as cultured pearls and fish meal.
Algaculture
The Algaculture process is the type of aquaculture that cultivates algae. Algae harvested are microalgae (phytoplankton, microphytes or planktonic algae) or macroalgae, commonly known as seaweed. While macroalgae are used for a variety of commercial purposes, its size and cultivation need to make it hard to grow. And microalgae are easier to harvest on a large scale.
Types of fish farming methods and systems
There are different types of fish farming systems, and the farmers can use one system or several at the same time. There are mainly two kinds of aquaculture they are extensive fish farming based on local photosynthetic production and intensive fish farming, in which the fishes are fed with external food supply.
The two main fish farming systems are;
- Extensive and
- Intensive systems
Extensive Fish Farming
The main examples of an Extensive system are a pond or irrigation ditch system. The major feature of such a system is that it is installed in a semi-natural environment, with natural food supply to the cultured fish. The farmer can regulate the environment of the pond with the help of several fish species and special equipment.
An extensive fish farming system is based on a semi-natural environment (example existing ponds), with natural food supply to the fish cultured such as algae, crustaceans, and zooplankton, etc. Production of food within the extensive system can be increased by “fertilizing” the pond (e.g. with animal waste). The natural balance within the extensive system is maintained by stocking the ponds with a variety of fish occupying different ecological niches. Fsh species are tilapia, which feed on algae, catfish, which feed off the pond bed, and species of carp, which feed on zooplankton. Care needs to be taken not to overstock the ponds or to over-fertilize, which can cause algal blooms and oxygen depletion, leading to large scale mortalities.
Examples of fish reared in the extensive fish farming system are catfish, carp, and tilapia.
The extensive fish farming system utilizes natural photosynthetic production of food (algae, plankton, mollusks, and crustaceans) to feed the fish. This type of farming isn’t the most productive, but it requires little labor, low overhead and little input from the farmer.
In the most extensive fish farming, the fish feed entirely from the food web within the pond, this can be enhanced by the addition of fertilizer or manure. And ponds (natural or artificial) and lagoons are fertilized to promote the presence of phytoplankton (microscopic plants), zooplankton (mostly small crustaceans) and aquatic vegetation which form the base of the aquatic food pyramid. This encourages the growth of marketable animals at a higher yield than that of the natural ecosystem.
You should not miss the Fish Farming License, Guidelines, Permission in India.
One of the common methods of farming bighead carp is to produce them in small lakes and reservoirs without the use of feed. The bighead carp are stocked with other fish species at a stocking density of 150 to 750 fish per hectare (i.e. 13-67 square meters per bighead carp) which represents about 40 to 50 % of the total number of fish stocked. Bighead carp are extensively reared in polyculture ponds and pens, where organic fertilizer is generally applied to increase natural food. This is also a type of extensive system of fish farming as “re-stocking” of natural populations. In this process, the fish is raised in tanks and then it is released in the wild to feed, but recaptured after receiving marketable size.
Ranching
This process of production is extensive and can be considered as a form of “re-stocking” of natural populations. The fish species are raised in captivity and released to feed in the wild, to be recaptured when they have reached marketable size. Ranching works for migratory species, returning close to the point of release (example salmon), or non-migratory, remaining for at least a substantial portion of the life-cycle in a restricted area. The main problem with this method is that the fish are open to exploitation by other parties. An example of fish reared in the ranching method is salmon.
Intensive Fish Farming
Intensive fish farming systems are often closed-circulation tanks (e.g. trout farming) or flow-through raceways. However, floating sea cages are intensive systems, which are open to the natural environment. In these farming systems, oxygen, water quality, and food supply are closely controlled. And the closed-circulation tanks have sophisticated water purification systems. This is a high-cost process of fish farming (due to feeding costs, and equipment, etc.), but the production rates are high and therefore offset the outlay. There is an increased risk of disease (due to stocking density) and a high degree of monitoring and expertise is necessary to run an intensive system successfully.
Intensive fish farming uses an external food supply are pellets, fish meal, corn, soy, even “ feather meal” to feed the carnivorous fish. The population density is high, antibiotic usage is high, food waste is very high, and sewage output is high in intensive fish farming. Water quality is paramount and generally requires a robust water purification system, if the farm is a closed system, like a pond, ditch, or tank. If the farm uses cages in rivers or the open sea, water purification isn’t as essential.
In an intensive farming system, the fish are kept at too high a stocking density to obtain significant amounts of feed from their environment. The levels of fish feed inputs and management of the water affect the stocking density of the fish that can be supported.
Examples of fish reared in the intensive farming system are cages – salmon, sea bass, tuna; raceways – trout; tanks – tilapia, sturgeon.
As for the intensive system of fish farming, this can be divided into;
- The completely closed system that is known as an integrated recycling system
- Flow-through or raceway that is called the semi-closed system
- An open system that is known as a floating cage system
Often farmers use closed-circulation tanks or flow-through raceways in such types of farming systems. There are floating sea cages, that are open to the natural environment, and they are related to intensive systems.
In this type of fish farming system, a farmer can simply control water quality, oxygen, and food supply. Most of the closed-circulation fish tanks are equipped with water purification systems. The intensive farming system is considered a high-cost method of fish farming, but it provides much higher rates of productivity. The disadvantage of this fish farming system is that the stocking density can become the factor that increases the risks of diseases among fishes. The other system is the “flow-through system” it is also known as classic fry farming, in this system, the species of the fish are raised in tanks and then released.
You may also like the Cost of Tilapia Fish Farming in India.
The other fish farming methods are;
- Semi-intensive fish farming
In semi-intensive, the fish still obtain important nutrition from the food web within their pond, but they are given supplementary feed. This means the fish can grow faster and to a larger size or at a greater stocking density. The feed can be of vegetable origin or may include fish, fish oil and fishmeal.
Grass carp is the fish species with the highest global production tonnage and is farmed, mainly in China, in both in semi-intensive pond systems and intensively in cages. In semi-intensive fish farming, the grass carp are stocked in ponds or pens with other carp species (as a major or secondary species), where aquatic weeds and terrestrial grasses form the main feed. Some of the commercial fish feeds, such as pellets, and vegetable by-products can be used instead to save labor costs, or at specific times of the year when the growth of water grasses and algae is reduced. The total stocking density is 750 to 3,000 fish per hectare (i.e. 3-13 square meters per fish).
Fish culture systems
Fish are raised commercially in four culture settings that are open ponds, raceways, tanks, and cages.
Cage system is one of the types fish farming methods
Cage aquaculture system involves the growing of fishes in existing water resources as being enclosed in a net cage which allows free flow of water. It is an aquaculture system made of a floating frame, net materials and mooring system (with rope, buoy, anchor etc.) with a round or square shape floating net to hold and large number of fishes and installed in reservoir, river, lake or sea. A catwalk is built around a battery of floating cages. Cage culture is an aquaculture system where fish are held in floating net pens. Cage culture offers the farmer a chance to utilize existing water resources in which most cases have only limited use for other purposes.
Pond system is one of the types fish farming methods
For preparing a fish pond system, farmers should first take into consideration the lowest possible risk surrounding the land such as rainwater run-off and flooding that may end up destroying the pond. Many times lime pound is treated with lime to ensure no water leaks and is left for 3 to 4 days before water is introduced. Also, the farmer can fertilize the water and wait till the water turn green and after 2 weeks, the fingerlings can be introduced into the pond. The system application of fertilizer is meant to neutralize the acidity in the water.
In small pond systems, the fish are often fed commercial fish food, and their waste products can help fertilize the fields. In larger pond systems, the pond grows water plants and algae as fish food. Some of the most successful ponds grow introduced strains of plants, with introduced strains of fish.
Pond systems are often connected with an above-ground irrigation system. Using this system, one can store one’s water allotment in ponds. Control of water quality is very crucial. And fertilizing, clarifying and pH level control of the water can increase yields substantially, as long as eutrophication is prevented and oxygen levels stay high. Many times, the aeration system is required.
Incase if you miss this: Integrated Fish Duck Farming.
Tank sytem is one of the types fish farming methods
The designing of a recirculation aquaculture system depends on the number of fish that can be carried in the tank. The number of fish species and their mass will define the feeding rates from which the individual engineering components are designed. The number of fish that can be stocked per unit volume will depend on the fish species and the fish size.
This fish tank design improves space utilization inside the tank and allows the production of more pounds of fish per unit of water flow. The water flow direction can be reversed periodically, helping to even outgrowth of the fish class by rearranging their feeding order. By avoiding the need to clean the tank floor of sediments fish stress and labor costs are reduced.
Raceways system is one of the types fish farming methods
The raceway is an artificial channel used in aquaculture system based on the continuous water flowing through the culture tanks and also known as the “flow-through system”. A raceway consists of rectangular basins constructed of concrete, should not be curved and equipped with an inlet and outlet. A continuous water flow-through is maintained to provide the necessary level of water quality.
Different types of fish culture based on number of species
Monoculture is one of the types of fish farming cultures
This process is the culture of single species of fish in a pond or tank. The advantage of this method of fish culture is that it enables the farmer to make the feed that will meet the requirement of a specific fish, particularly in the intensive culture system. Fish of different ages can be stocked thus enhancing selective harvesting. The culture of trout, tilapia, catfish, and carps are the main examples of monoculture.
Polyculture is one of the types of fish farming cultures
The polyculture process is the practice of culturing more than one species of aquatic organisms in the same pond. The motivating principle is that fish in ponds can be maximized by raising a combination of fish species having different food habits. The mixture of fish gives better utilization of obtainable natural food produced in a pond.
Ponds that have been enriched through chemical fertilization, feeding practices have abundant natural fish food organisms living at different depths and locations in the water column. Most fish feed predominantly on selected groups of these kinds of organisms. Polyculture must combine fish having different feeding habits in proportions that efficiently utilize these natural foods. And as a result, higher yields are obtained. Efficient polyculture systems in tropical climates can produce up to 8000 kg of fish/ ha/year. The success of polyculture mainly depends on synergism and available food.
You can also check the Growing Coriander in Aquaponics.