Traditional shrimp farming systems are of four types according to shrimp cultivation management, production, stocking density etc. The systems of shrimp farming are listed below.
- Extensive System
- Improved Extensive System
- Semi-intensive System
- Intensive System
A short description of those farming system including farm management, stocking rate, production are given below.
Extensive system is the easiest shrimp farming method. This is the oldest method with low risk and requires little funds. This shrimp farming method is totally dependent on nature. Shrimps are cultivated without serving any supplementary fish feed. This system is available in Bangladesh and some other Asian countries from the ancient time. In this system the shrimp farming pond are not build in proper planned way. The area of the farm become more than 20 hectors. Embankment of the bank become sloping with water depth of 0.3-1.2 miter. Bottom soil is bumpy and has no canal for drainage. Water management is irregular and the farm is not free from cannibalistic and unwanted fish. The shrimp has not serve any supplementary feed. Generally 10-15 thousand minnow are stocked per hector. In extensive system of shrimp farming other fish species can also be cultivated with shrimp. About 200-250kg shrimp produced from this cultivation system. About 85-90% land are being used for shrimp cultivation in this system in Bangladesh.
Improved Extensive System
Improved extensive system of shrimp farming needs planned pond design, canal for drainage of water, suitable embankment etc. Water pump are kept for sufficient water management. Organic and non-organic (chemical) fertilizer and supplementary feed are provided to the fish. In improved extensive system about 30-40 thousand minnow are stocked per hector. 400-500kg shrimp per hector can be produced by using this method. This system needs medium capital and risk is low. Lime and fertilizer are used for improving the qualities of soil and water. It is very necessary to remove cannibalistic fish and harmful aquatic insects and prevent various types of aquatic weeds.
Semi-intensive system is applied in small sized pond. The basal level of the pond is plane, pond is sloping to a side and fully precipitable. It has planned water supply management, controlling cannibalistic fishes and serving high quality pullet feed facilities. About 0.2-0.3 million minnows are stocked per hector and served sufficient food. This types of farm produce about 4-5 tons of shrimp per hector every year. Semi-intensive shrimp farming system needs experienced people and high capital. Measured lime and fertilizer are used for producing sufficient natural food of fish in the pond. Machines are used for making oxygen in the water of pond and removing clay from the basal level of pond.
Shrimp farming in intensive system is very expensive. Many countries around the world use this system for shrimp farming. In this types of system natural food are produced for fishes by using lime and various types of fertilizer in the pond. High quality water and serving high quality pullet feed is essential for intensive system. The pond sized bellow one hector is suitable for this. About 15 minnow are stocked per square miter and it produces about 5-10 tons of shrimp per hector. The farmer needs to be very careful for intensive shrimp farming system.