FISH POND CONSTRUCTION AND MANAGEMENT
ESTABLISHMENT/CONSTRUCTION OF A FISH POND
a fish pond is generally established to keep or house fishes. fish pond can artificial or natural.
fish pond can be built in-house or around riverine areas. in which ever type is to be constructed will be determined by the types of fishes to be reared
The following operations are normally carried out when establishing a fish pond:
Site selection of fish pond
Site selection involves the choice of best site based on necessary conditions like a piece of land through which a perennial stream flows. The site should be on a fertile and clay soil to prevent seepage of water. It should have a valley with narrow neck and a fairly open area.
Reconnaissance or general survey of fish pond
Detailed survey of the chosen site should be carried out, especially by extensions workers. Such workers help to determine the height of pond, volume of earth to be used for dyke, total water
surface area, volume of water in the pond or embracement.
Clearing and stumping of site of fish pond
: This involves the removal of thrash, cutting of trees and removal of stumps.
Construction of fish pond
Dam is usually constructed across the stream. Materials used in the construction should be of good quality. Clay soil should be used for dam construction because of its ability to hold water
Construction of core trench
This involves the removal of the soil or excavation. It is positioned at right angle to the dam. Such dam should be made with consolidated stones or cement walls.
Construction of spill way of fish pond
: Spill way is positioned at one end of the dam. Wood and wire-mesh screen should be used to construct the spill way.
Impoundment of fish pond
: This involves the filling of the pond with water by opening the monk board of the reservoir. This leads to the release of water and flow to fill the pond
Liming of fish pond
: This involves the addition of limestone or calcium carbonate powder to the sides and bottom of the pond to seal pores and prevent water loss. Liming also reduces acidity of the pond water and encourages the growth of planktons (fish food). However, liming is done before filing the pond with water. The lime materials should be left for four weeks in its dry state.
Pond fertilization of fish pond
Fertilizer encourages the growth of planktons (fish food). Pond fertilizer is done by pouring organic fertilizers such as poultry droppings, cow dung or the use of inorganic ones like N.P.K or super phosphate. Pond fertilization should be carried out 15 days before stocking pond with water.
Pond inoculation of fish pond
This is the introduction of proper planktons species into the pond. This is done by obtaining some water from a plankton-rich pond and pour into a newly fertilized pond. When the pond water begins to turn green, this green water indicates the abundance of planktons (natural food of fish). To keep the water green, fertilizer is added into the pond every week.
Stocking of pond
: This is the introduction of the proper baby fish called fingerlings or fries into the pond. The pond is stocked at the rate of two fingerlings per square metre. The fingerlings should not be poured into the pond. Rather, the container should be placed gently into the water and the fingerlings allowed to swim into the water pond themselves.
1CONDITIONS OR FACTORS NECESSARY FOR SITING A FISH POND
The factors or conditions necessary for siting a fish pond include:
(1) Adequate water supply
(2) Soil in the area
(3) Vegetation of the area
(4) Topography of the area
(5) Availability of fast growing fishes.
(6) Availability of supplementary feedstuff
Adequate water supply of fish pond
There must be constant supply of water of good quality and quantity. The water can be from streams, lakes, rivers, irrigations canals and springs. Good quality water is necessary because it will provide oxygen and food to fish, create a medium for waste discharge and reproduction. The water should not have a bad smell, taste or colour and should not be too muddy and must be free from pollution.
Soil in the area of fish pond
soil in the area must be fertile so as to supply nutrients to the fish. It should be clay because of its ability to hold water which is very important in fish pond construction. Soil with too much sand or gravel is not good and would not retain water.
Vegetation of the area of fish pond
Low vegetation, especially grasslands are preferred. Woody sites are not suitable because clearing and stumping will greatly increase the cost of setting up the fish pond.
Topography of fish pond
: The shape of the land should allow for easy draining and filling of pond with water. The waste must flow from a place that is higher than the pond so that the water can flow into the pond directly. If not, the need for water pumps would arise and this will increase the cost of the p rejects. However, fish pond can be constructed on a flat or level ground but lots of soil have to be removed to create the slope.
Availability of fast growing fish of fish pond
Fingerlings or baby fish for stocking a fish pond should be the type that can grow fast and mature within a very short time. The use of improved varieties (breeds) in stocking fish pond makes fish farming more profitable.
Availability of supplementary feed stuff of fish pond
: Supplementary feeding is done to ensure rapid growth of fish and allow high stocking density. Artificial or compounded feeds in form of pellets are used to supplement the natural feed (planktons). The addition of fertilizers also promotes the rapid growth of planktons (natural fish food) in the pond.
FEATURES OF A STANDARD FISH POND
The essential features of a standard fish pond include.
(ii) Core trench
(iii) Distribution channel
(iv) Spill way
(viii) Dam slope (inner and outer).
(i) Dam: This is the large area of the pond that holds water. It ensures the availability of water In the pond.
(ii) Core trench: This is the excavated portion of the fish pond. It consolidates the walls with stones and cement.
(iii) Distribution channel: This is the area which helps to introduce water into the pond. Water is distributed to all the sections of the pond until it gets to a particular volume. Fertilizers can equally be mixed up with the water and distributed together.
Spill way of fish pond
: This is a passage for water to flow over or around a dam. It is positioned at one end of the dam. It uses wood or wire-mesh screen.
Monk of fish pond
: The monk regulates water level automatically in the pond. It helps in the discharge of water from both the surface and bottom. It has vertical low and horizontal culverts or pipes. They are constructed with concrete.
Boards of fish pond
: These are structures which regulate the flow of water. They are made up of desirable wood and also hold water inside the pond. They are fitted at the centre or middle of slabs at the gates.
(vii) Screens: These structures help to prevent the entry of undesirable species of fish into the pond. They also prevent fish movement out of the pond.
(viii) Dam slope (inner and outer): This helps to regulate water movement into and out of the pond. It also ensures the availability of water in the pond. It is usually constructed at the beginning and end of the pond.
MAINTENANCE OF A FISH POND
To ensure the continuous availability of fish in a fish pond or maintain high fish yield, it is necessary to ensure;
Regular feeding of fish pond
: The fish must be fed twice daily from selected point(s). supplementary feed in the form of compound feed should be given in sufficient quantity to ensure rapid growth and early maturity of the fish.
Deweeding of fish pond
: This is the removal of weeds from the pond. It allows the dissolution of oxygen in water, the penetration of sunlight to the bottom of the pond which will promote the growth of fish food (planktons). It also prevents the build-up of pests and diseases.
Desilting of fish pond
: This is the removal of silt or prevention of silt from entering into the pond. Desilting makes the water to be clean, prompts easy movement of fish within the water and also prevents pollution of the water.
Aeration of fish pond
: Aeration enables oxygen to dissolve in water which is required by fish for respiration. Fishes usually come to the surface of water due to lack of oxygen in the water. Weeds, excessive organic manure, overstocking, etc prevent proper aeration of the pond.
Constant supply of water of fish pond
: The pond should always be filled with water and any leakages reared.
(6) Control of predators: Predators like birds and snake should be prevented from entry into the pond because they could eat up the fish in the pond. This can be done by keeping the pond’s surrounding clean (i.e. constant weeding)
Prevention of diseases of fish pond
Diseases should be prevented as this could kill all the fish in the pond. Adequate feeding, stocking, temperature, manuring, weeding, etc help to prevent diseases.
Regular harvesting of fish pond
Regular harvesting of fish is necessary to prevent over-population, outbreak of diseases and cannibalism. Periodic or total harvesting could be done six month after stocking, using net or by draining of the
Regular application of fertilizer of fish pond
This should be done once in a month to promote the growth of fish food (planktons) in the pond.
WEED AND THEIR BOTANICAL NAMES
1. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
3. 52. SOIL MICRO-ORGANISMS
4. ORGANIC MANURING
5. FARM YARD MANURE
6. HUMUGRAZING AND OVER GRAZING
10. IRRIGATION AND DRAINAGES
8. CROP ROTATION
11. IRRIGATION SYSTEMS
12. ORGANIC MANURING
13. FARM YARD MANURE
16. CROP ROTATION