Fish farming is undoubtedly one of the fastest growing agriculture enterprises in Nigeria. The importance of fisheries to the Nigeria economy is indicated by its contribution to the gross domestic product being 5.4% in 2002 (FDF) Nigeria are high fish consumers with a total current consumption figures of about 1.5million metric tons.
With an annual fish import figure of about 700,000 (FAO, 2000) metric tons, Nigeria remains the highest importer of fish and fishery products in Africa.
The contribution of fisheries to the nation economy is very significant in term of employment, income generation, poverty alleviation, foreign exchange earnings and provision of raw materials for the animal feed industry.
The local supply of fish and fishery products consists of production from the artisanal (85%), industrial (14%) and Aquaculture (1%) subsectors (FDF 2005).
Fish contributes immensely to the enhancement of national health as it contains Omega III fatty acid that reduces the risk of cardiovascular diseases, hypertension, arteriosclerosis etc. Fish is thus medically prescribed as preferred animal protein especially to the age bracket 50years and above. Omega III fatty acid is also responsible for proper development of brain cells in developing foetus. Fish is a welcome diet for pregnant mothers and young children for good health and mental development. It is said to enhance high Intelligent Quotient (IQ) in developing children.
How to start Fish farming:
- STEP1:
SITE SELECTION: Proper selection of site is probably the most important factor in the success of a fish farm. However, as ideal site is often not available, so you have to compromise. Site selection will depend on the kind of fish farm you plan to use for pond construction you need to consider the following factor:
Things to consider when constructing a Fish pond
a. Source of Water: Water is very important in fish culture. It can be obtained from direct or indirect run offs, streams, spring, lakes, rivers, reservoirs, irrigation canal, well and bore holes.
Where river or stream water is not reliable, conservation dams or tanks may be built to store water.
The quality and quantity of the water available is important.
When using water from Tap; such water must be exposed to the atmosphere for minimum of 48hours to ensure that the chlorine content vaporized off.
A constant supply of water is needed not only to fill the pond, but also to make up for the losses caused by seepage and evaporation.
Investigation of the amount and seasonality of water sources, as well as their position in the field regarding possible pollution is very important in site selection.
Water temperature of between 270C to 300C is generally good for fish farming.
Variation in water salinity is also an important environmental factor which must be considered. Some species can withstand a wider salinity range than others: e.g. tilapia and catfish can withstand a wide range from fresh to seawater which carp can only tolerate freshwater.
b. Soil Type: The quantity of soil influence both productivity and water quality in pond. However, it must be suitable for like construction.
Soil texture (Particle size composition) and porosity or permeability (ability to let water pass through) must be considered.
The pond bottom must be able to hold water (e.g. clay)
Soil should also contribute to the fertility of the water by providing nutrient.
Therefore loamy-clay soil is ideal for pond construction.
c. Topography: The land contour and especially the land slope, determine the way to build pond.
Totally flat land and a hilly terrain with a slope of more than 2% to 4% are unsuitable for pond construction so all slopes between 2% and 4% can be used for pond construction.
A 2% land slope means 2cm vertical decline for every meter of horizontal distance.
d. Market: In selecting a site for fish farming accessibility to market must also be considered
Types of Fish ponds:
- EARTHEN POND: In locating an earthen pond land with gentle slope is selected and probably with a layout that take the advantage of the existing land contour. During Construction, the Pond may be dugged into the ground, they may be kept partly above the ground or they may be below the original ground elevation. slope and bottom should be well packed during construction to prevent Erosion and Seepage. The Soil should contain a minimum of 25% clay. Rocks grass, branches and other undesirable object should be eliminated from the dykes.
- CONCRETE PONDS (Homestead Pond): homestead ponds are constructed with blocks because of the high cost of casting a full concrete structure.
- BARRAGE PONDS: Are made by building a dyke across a natural stream. The pond are therefore a small conservation dams. The advantage of a barrage pond is that it is easy to construct. However it is very difficult to control this system. It is equally difficult to keep wild fish out and a lot of food added to the pond will be loss because of the current.
How to Prepare a Fish pond:
Preparation of old and new ponds is done to create a requisite environment for the well-being and growth of the fish to be stocked. The principles of preparation are basically the same for old and new ponds.
 Though there are minor contingent differences in pond preparation which generally involves lime and fertilizer treatment of the pond bottom (to reduce loss by seepage, improve pond fertility and stimulate plankton production) flooding of the pond and maintenance of optimum water depth, checking of pond walls and bottom as well as water inlets and outlets to repair damages, sanitation and disinfection of ponds as well as desiltation.
LIMING
Quick lime/Slake lime – 20 – 50gm/m2
Agriculture lime – 50 – 200gm/m2
The ground and powdered lime should be broadcasted over the entire dried pond bottom and left to dry on the soil for 14days. The pond is then flooded up to 60cm (above the knees).
FERTILIZATION: This is carried out immediately after liming to improve pond fertility and stimulate plankton production.
Apply inorganic manure (NPK, SSP, TSP etc) or preferably animal manures (e.g. Cow, pig, poultry etc) to already flooded ponds to stimulate natural fish food production.
For inorganic manure, fill a jute bag with fertilizer and submerge it under water, OR dissolve the fertilizer inside a plastic bucket and sprinkle over the entire surfaces.
For organic manure, fill jute with the manure and tie to stake at various points in the water OR collect manure in a large tank then mix with reasonable quantity of water. After mixing use the liquid part of the mixture in the fish pond. For cattle dung (100g/m2), Chicken (50g/m2) Urea (2g/m2), (TSP 5g/m2) once in 2weeks.
IMPOUNDMENT:
Fill ponds slowly and gradually to avoid mud stirring at the pond bottom, Turbidity (from silt, sand, clay particles), and possible dyke collapse from uneven wetting. The pond should be filled with water between 1 – 1.5m level in readiness for stocking.
STOCKING:
Normally takes place after pond preparation, liming and fertilization and is the means of introducing adequate number of selected fish species of proper size into the pond for culture.
For earthen pond stocking density of 20-30 fish/m2 is recommend. While in concrete tank with adequate water 40-50fish/m2 can be stocked. However, the stocking density in a re-circulatory system could be up to 100fish/m2.
Note that only healthy and disease free fingerling/juvenile must be stocked.
Stocking is carried out late in the evening or very early in the morning.
FEED AND FEEDING:
The success of any fish farming ventures like other livestock is determined by the quality and quantity of feed given to the stock. Proper and adequate feed shorten the production period and ensure good size fish which command high market value.
It is recommended that fish should be fed regularly, at least twice daily at specific times (usually 10.00am and 5.00pm) at specific feedings spot and by gradual broadcast till the fish cases to come up to feed.
Avoid overfeeding to prevent fouling and pollution of water by unconsumed feed decomposed to form smelly and harmful gases like Ammonia, Hydrogen Sulphide and Carbondioxde which have adverse effect on fish growth and survival.
Drain part of pound water and replace with fresh water it you notice fouling.
Experience had shown that it’s better to starts off with floating feed and graduate to a locally produce pellet in 8-10 weeks period fish are fed with 4-7% of their body weight/day. The feed/day could be administered 2 or 3 times and the sample size fish taken in every 3 weeks to determine possible change in quantity of feed required. For the locally produced fish pellet reputable feed miller can be approached and if need be proximate analysis of the content of the feed made to be sure that it meet the nutrient need of your fishing
How to calculate the quantity of feed Required:
The quantity of feed required to feed fish daily can be calculated if the stocking density and the average weight of fish can be estimated. This can be done by sampling the fish either bi-weekly or monthly.
Example: if a fish farmer has 1000 fingerlings of 10g average weight in 1 hectare of fish farm. The daily feed requirement at 5% feeding rate will be
Where F= Weight of feed
 W = Weight of fish
 S = Stocking rate
 P = Percentage body weight
 Table 1: Hatchery feeding table, based on optimum water quality and water temperature of 27 – 300C. Fry is fed to satiation (over 6% body weight/day).
Feeding time (days) Average weight (grams) Crumble size (mm)
0 – 7 0.025 Artemia + 0.2 – 0.3
7 – 14 0.05 – 0.10 0.2 – 0.3
14 – 21 0.10 – 0.15 0.3 – 0.5
21 – 28 0.15 – 0.30 0.3 – 0.5
28 – 35 0.30 – 0.50 0.5 – 0.8
35 – 42 0.50 – 1.5 0.5 – 0.8
42 – 49 1.5 – 3.0 0.8 – 1.2
49 – 56 3.0 – 5.0 1..2 – 1.5
Table 2: Growth-out feeding Table, based on optimum water quality and water temperature of 25 – 270C
Average weight (grams) Feed level (%body weight/day) Pellet size (mm)
5 – 10 5.5 – 6.0 1.2 – 1.5
10 – 50 4.5 – 5.5 2.0
50 – 100 4.0 – 4.5 3.0
100 – 250 3.0 – 4.0 4.5
250 – 500 2.0 – 3.0 4.5 or 6.0
500 – 750 1.5 – 2.0 4.5 or 6.0
750 – 1000 1.1 – 1.5 4.5 or 6.0
1000 – 1250 0.9 – 1.1 4.5 or 6.0
1250 – 1500 0.8 – 1.0 4.5 or 6.0
1500 – 2000 0.7 – 0.9 4.5 or 6.0
FORMULATION FOR 40% CP DIET (100KG) FOR GROWERS
1. Fish meal                      20kg
2. GNCÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 35kg
  3. Soya                          23.07kg
4. Maize                         16kg
5. Wheat offal                     2kg
     6. Methionine                    0.50g
     7.   Iysine                         0.50g
8. Vitamin premix                 0.5g
     9.  Bone meal                     1kg
     10.  Binder                        2kg
             FINISHER FEED FOR CATFISH
    1. GNC                          25kg
    2. FF soya                        20kg
    3. Maize                         20kg
    4. PKC                          20kg
    5. Bone meal                      2kg
    6. Fish meal                      10kg
    7. Dicalcium sulphate               0.5g
    8. Vitamin C                      0.5g
    9. Salt                           0.5g
   10. Premix                        0.5g
   11. Red oil                        1litre
WATER QUALITY MANAGEMENT
Water is the most fundamental requirement for fish farming because without suitable water supply the farm can never be successful.
Why is water Quality so important?
It is the home of fish
It provide oxygen and food for the fish
It is a medium for waste discharge such as CO2, Nitrogenous waste and excreta.
It is medium for reproduction
The Quality of a good water to supply to fish pond
Quality water is free of odour, taste and colour. A good water must also have, enough dissolved oxygen, appropriate pH, water free of suspended particles and pollutants such as detergents herbicides and toxic waste mainly from factories and houses.
Dissolved Oxygen (DO)
Fish require adequate concentrations of dissolved oxygen for survival and growth.
Oxygen dissolves in water from the atmosphere or can be produced by plants found in water through photosynthesis.
Oxygen of 4mg/ Litre and above is considered adequate for fish.
Shortage of oxygen can be caused by competition for water use by other animals and plants, decay of animal and plant materials in water and decomposition of uneaten feeds by bacteria.
If oxygen is in short supply, fish become restless, swimming to the surface to gasp for air. In very acute shortage the fish will be jumping out of water foul smell of water is another indicator of low oxygen.
You can test the water to know the condition of 02 by spitting into the water. If the form remains intact for over 5-6minutes, 02 is low in the water.
Oxygen level in pond can be improved by agitating or mixing the water with sticks and aerator. However in critical situation the water may be completely drained and critical situation the water may be completely drained and replaced with fresh, well oxygenated water
pH
This is a measure of acidity or alkalinity of level of water. The pH scale ranges from 0 -14. The neutral pH points 7with pH above 7 alkaline and below acidic.
The best water for fish culture is Natural or Slightly alkaline (pH 6.5 – 8.5)
You can determine the pH of your pond H20 by use of pH indicator paper. The paper indicator changes colour when dip in pond water and the colour is matched with the colour indicated on the chart to determine the pH level of the water. Water can be limed to correct acidic pH and sodium bicarbonate can be added to pond water under expert supervision to correct extreme alkaline condition.
pH Table
pH < 4Â Acidic death point
4.0 – 5.0 No reproduction
4.0 – 6.5 Slow growth
6.5 – 8.5 Desirable range
9.0 – 11.0 Slow growth
   pH > 11 Alkaline death point
TURBIDITY
Suspended particles, silt and clay in ponds usually make water turbid.
Turbidity reduces light penetration and level of photosynthesis.
You can know that your pond water is turbid if you notice a change of colour from slightly Greenish to Brown.
Also if you dip your hand inside pond water and discovered that your palm cannot be seen before your elbow reaches the water level then the water is turbid.
Secchi disc can be used to determine turbidity level Secchi disc reading (visibility) of 40-90cm is adequate.
If turbidity is as a result of run-off around the pond, drainage can be constructed to divert it away. Alliteratively the water can be changed completely or Alum can be added to the water under expert supervision.
FISH WASTES
Wastes are from uneaten food, CO2 given out during respiration and fish faeces.
Accumulation of wastes can be noticed though foul smelling emanating from the water colour changes in water e.t.c.
As a preventive measure do not over feed fish or remove uneaten feed before of become nuisance.
You can drain the water off completely and replace with fresh one as a last resort.
POLLUTANTS
These are substance such as waste materials from agriculture industries and households, which find their way into the pond water. Oil film scum foam and sometimes massive death of fish could indicate presence of pollutants in water.
To correct this, do not locate pond water to sources of pollution.
Divert run-offs from agricultural by re-channeling.
RECOMMENDED WATER QUALITY REQUIREMENT FOR CATFISH
Temperature 27 – 300 C
pH 6.5 – 8. 5
Dissolved Oxygen    >3. 0mg /litre
Carbondioxide    < 20mg/litre
Total alkalinity 50 – 100 m,g/litre (caCo3)
Un-ionized ammonia   < 0. 1 mg /litre
Nitrite 0.5mg / litre
Some Common Fish Diseases and treatments
Disease is any condition of aquatic animals that impairs normal physiological functions. Fish disease outbreak increase production cost because of the investment lost in dead fish, the cost of treatment and decrease growth during convalescence.
Parasites and bacteria may be of minimal significance under natural condition but can contribute to substantial problem when animals are crowded and stressed under culture condition.
Fish health management are designed to prevent fish disease once fish get sick, salvage may be difficult.
Ability to recognize a disease condition in a fish population is essential to early detection and effective control. Some visible signs of disease are:
Change in body colour
Presence of swellings or nodules on body
Erratic or sluggish swimming
Emaciation
Mortalities
Skeletal deformities
Presence of hemorrhagic spots on the body and so on.
Infections diseases are caused by pathogenic organism present in the environment or carried by other fish e.g
Parasitic diseases
Bacterial diseases
Viral diseases
Fungal disease
Non infectious diseases – are caused by environmental problem nutritional deficiencies or genetic defects.
Table 3: Some Common Fish Diseases and Treatment
DISEASES SYMPTOM PREVENTION/ TREATMENT
AÂ Â Â Â Parasitic
(i) Tapeworm e.g Corallobithrium finbriatum: There may be no outward indication but fish may lose weight or become sterile. Avoid maintaining or purchasing infected fry.
Drain, dry and disinfect ponds after each harvesting
No therapeutic agent available.
(ii) Ich or white spot disease Small raised spots over the entire body surface and fins.
Heavily infected fish often congregate at the intake or outlet of pond Avoid contaminated water supply nets and other equipment.
Provide good water and balanced feed.
formalin table salt copper sulphate and potassium permanganate can be used as therapeutic agent
(iii) Fish lice Infected Fish Will Flash Or Rub Against Tanks
Show red spots Stocking of parasite for fish
Masoten (Dylox) can be used as therapeutic agent
BÂ Â FUNGUS
– (i) Saprolegenia and Achyla
Fish have general cotton- like appearance associated with discolored area or lesions.
Fungus assumes the colour of material suspended in the water
Maintain good water quality and nutritionally adequate feeds.
copper sulphate, potassium permanganate, or formalin can be used
CÂ Â BACTERIALÂ
Bactermia
(Haemorrhagic septicemia
Shallow, irregular- margined reddish sores on sides.
Pop eye
Enlarged fluid- filled belly.
A reddened area around the anus
Avoid overcrowding and rough handling.
Provide good water quality and feed well fortified with vitamin C
Oxytetracyline addition to diet is therapeutic
(ii) Columnaris Discolored patches and scale loss.
Mouth and barbell erosion, fin erosion, tail erosion
30- 70% mortality Treatment of water with KMn04
Medication of feed with Oxytetracycline
(D) NUTRITIONAL
(i) Broken back diseases
(ii) Broken head diseases
(iii) No blood diseases
Deformation of spinal cord
Crack on the head
Fish become anaemic and die
Fortify feed with vitamin C
Vitamin C and bone meal added to feed
Folic acid which is added to new feed after the old one as discarded
 FISH SEED MULTIPLICATION
The production of fast growing and genetically variable fish seed is very crucial to the development of profitable fish farming venture. Also, turn-over from production. Due to wide Demand-Supply gap investors in fish seed business have wide market opportunities for their production; it is equally possible to combine fingerling production with tearing of table fish. In fact, money realized from fingerling sales could be invested in the feeding of the table fish. However, the following factors are very crucial for any successful commercial fingerlings production.
Availability of standard hatchery where temperature and other physico-chemical parameters could be regulated.
Availability of good quality water source
Good quality brood stock bank.
Good quality feed for fry and fingerling
Adequate marketing networks.
Moreover a good seed production programme must be cognizance of the followings.
Brood stock selection
Hypophysation
Procurement of ripe eggs and milt
Fertilization and incubation of eggs
Hatching and incubation of fry
BROOD FISH SELECTION: Brood fish care is very important in hatchery operation because these are the parent fish that would produce the offsprings which constitute an important base in aquaculture.
Brood fish can be obtained from a farm with a known history of a well articulated management practices and the age of the brood fish confined.
Upon procurement all brood fish should be disinfected with (Sodium hypochlorite) or other mild disinfectant before being introduced to brood fish pond.
Brood fish of Clarias sp, Heterobranchus sp should be fed on artificial diet of between 30 to 40% crude protein 25-30% crude `protein is recommended for Tilapia brood fish. The feeding rate is generally 2-3% of their body weight.
Size of spawners should be at least 500g – 800g and age should not be less than 9 months.
HYPOPHYSATION: This is a simple technique of breeding fish under controlled condition involving injecting hormones into the fish. The injected hormones induce the fish to release eggs within 10-12hours depending on water temperature.
0.5ml of ovaprim is injected for 1kg of female brooder
0.2ml ovatide is injected for 1kg of female brooder
Pituitary extracted from fish of equivalent weight fish is injected to brooder
Male is dissected to collect testis which is dried with filter paper
Incise the testis lobes, gently squeezing and washing the milt into a container with 0.9% saline solution. The saline solution prevents the milt from being motile and can be stored in refrigerator at 40C for no longer than 2 days.
TIME AND METHOD OF INJECTION
At a temperature of 270C, stripping is done about 10-12 hours after injection.
The needle should be inserted gently about 2cm into the fish about 200- 400c to the body in the direction of the tail spot carefully rubbed (dorso-ventrally)
FERTILIZATION AND INCUBATION OF EGG
After injection, stripping can be done 10-12 hours. This is done by gentle pressure on the female brooder abdomen.
Eggs are stripped into plastic or enamel bowl.
The egg is mixed with already collected milt and thoroughly diluted with 0.9% salt solution.
Contact with water should be avoided until the eggs and milt make adequate contact.
Fertilization is completed as soon as the mixture of the egg and milt thoroughly come in contact with water
The fertilized eggs are then spread on receptacle such as kaka ban, mosquito nets in a single layer and incubated in hatching trough which could be made of plastic, glass, wooden or concrete tanks
Due to high oxygen demand at this state, the fertilized eggs need highly oxygenated water. (Water flow- through system is set up until hatching is completed.)
Hatching takes place between 18-36 hours after fertilization depending on water temperature.
The hatchlings will swim out of the kakaban while the unhatched egg will be retained.
CARE OF FRY (Hatching)
Separation of hatchlings from unhatched eggs and deformed larvae is the first major step to be taken to prevent growth of fungi on the egg shells, dead eggs and deformed larvae that are harmful to hatchings.
This can be done successfully by leavings a spot free of fertilized eggs during incubation in the hatchings troughs and this area is covered to make the spot dark.
The healthy larvae will then swim into the darker part under cover and cluster at the edge of the tank.
Egg shells, dead and deformed larvae are then siphon-out.
Feeding of fry starts 3-4days after the absorption of the yolk.
Feeding with natural live food such as zooplankton, Artemia and so on is preferable
Also artificial feed such as cyprico, 72% Fish meal and Egg yolk can be used to feed fry.
The fry must be fed 6 to 8 times daily with small quantity of feed.
The fry are transferred into a nursery pond rich in zooplankton after one week in the trough.
The fry can be stocked at the rate of 200 fry/m3 in the nursery pond.
Fry should be protected from predators such as bigger fish frogs, toads and their eggs by adequate fencing and good pond preparation.
Generally for the best performance of catfish in the hatchery and nursery, the recommended percentage crude protein level for starter (fry) is 55. to 65% while grower (fingerling feed) 55%
RECORD KEEPING IN FISH FARMING
It is imperative to keep records of fish farming activities in a note book. Record keeping can be said to be the core of fish farm management practices. It helps to achieve the maximum possible rate of fish production for three broad reasons:
i) it assist in evaluating the profitability and general economics of pond investment
ii) it provide vital management information for future planning, improvement and development.
iii) it provides necessary grounds to get credit from financial institutions.
The book keeping system pay attention to two major aspect of recording:
Account keeping- this is concerned registering all receipts(sales, income cash, money received) and payments(expenditure, money spent, and outgoing cash.)
 harvesting and sales details.
TYPES OF RECORDS
a. Construction cost- Records of money expended on pond construction(earthen or concrete), purchase of fiber tank or plastic tank, and plumbing work carried out.
b. INPUTS RECORDS
Date Input type QTY(NO&kg) Cost/units(N) Total cost Remark
c. HARVEST AND SALES RECORDS
Date Type of fish crop QTY(kg&NO) Price or sale value(N) Total sales
