Commercial Fish Farming

Commercial Fish Pond Farming business in nigeria

Fish is a healthy, protein-rich and tasty food with low cholesterol and calories. The requirement of fish is one of the main components of animal protein in diet computed at about 12 kilograms per year per person.

Human population growth has placed a significant demand on fish as a food source, and overfishing in the past 50 years has significantly reduced fish populations across a large number of species. With dwindling stock of wild fish in the oceans, rivers and seas; fish farming is an ancient practice that can provide many profitable opportunities today.

“Aquaculture, also known as aqua-farming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants”.

Fish farming is a process of ‘raising fish commercially in tanks, ponds or other enclosures for the purpose of producing food’. It is a profitable business that’s widespread across various parts of Nigeria. The insatiable demand for fishery products like Tilapia, Catfish, and Mackerel (Salmon) make the industry one of the most lucrative agricultural business segments to venture into.

FISH FARMING

First thing you will need to start a home-based fish farming business is some basic knowledge about raising fish.

There are five different types of fish farms that utilize different aquaculture methods. These are irrigation ditch or pond systems, cage system, composite fish culture, recycling systems and classic fry farming. 

  • Irrigation ditch or pond systems: The main requirement for the utilization of this method is to have a ditch or a pond that holds water. It is a unique system because at a small level, fish are artificially fed and the waste produced from the fish is then used to fertilize farmers’ fields. On a larger scale, mostly in ponds, the pond is self-sustaining as it grows plants and algae for fish-food.
  • Cage system: involves the use of cages that are placed in lakes, ponds and oceans that contain the fish. This method is also widely referred to as offshore cultivation. Fish are kept in the cage like structures and are “artificially fed” and harvested. The major concern of the cage method is fish escaping from the cage and being lost.
  • Composite fish culture: Allows for both local fish species and imported fish species to coexist in the same pond. The number of species depends, but it is sometimes upwards of six fish species in a single pond. The fish species are always carefully chosen to ensure that species can coexist and reduce competition for food.
  • Recycling systems: This method uses large plastic tanks that are placed inside a greenhouse. There are hydroponic beds that are placed near the plastic tanks. The water in the plastic tanks is circulated to the hydroponic beds, where the fish feed waste goes to provide nutrients to the plant crops that are grown in the hydroponic beds.
  • Classic fry farming: this method is also known as “flow through system”. This is when sport fish species are raised from eggs and are put in streams and released.

In Nigeria, most fish farmers operate on small-scale to medium scale farms ranging from homestead concrete ponds and tanks to small or large earthen ponds.

Fish are excellent animals to rear. They can convert feed into body tissue more efficiently than most farm animals, transforming about 65 percent or more of their feed into flesh. Fish also have excellent dress-out qualities, providing an average of 60 percent body weight as marketable product and a greater proportion of edible, lean tissue than most livestock.

Commercial Fish

Fish farming is, like most other types of farming, a risky business that requires  knowledge, skills, and careful considerations. Individuals with little or no experience in fish farming and few resources available can become successful fish farmers, but they should start small and expand slowly, and be willing to invest lots of time and effort.

Fish Pond farming business in nigeria

Fig 1. Flow Diagram: Four-Step Process to Establish a Commercial Fish Farm

The objective of commercial fish farming is to produce fish for sale and earn profits. Therefore, production should be planned from the onset to target identified markets. In order to do this one should, have the required product (size and form) available when the market wants it, be able to produce adequate volumes to sustain targeted markets and finally produce at a competitive price and profit.

Land and Water Supply

Two major requirements for starting a successful fish farm (before construction of the pond or ponds) are sufficient physical space (land) and a good supply of high- quality water. The amount of land and water available limit the type of rearing facilities and number of fish that can be reared. Water quality also restricts the type of fish that can be reared and production rates.

Ideal Fish  – The fish species should have the following characteristics:

  • Have well-known culture requirements;
  • Be adaptable to many types of culture systems;
  • Exhibit rapid growth to a large maximum size;
  • Readily adapt to artificial feeds;
  • Be tolerant of crowding and high density conditions;
  • Exhibit high survival i.e. low mortality rates;
  • Be easy to handle, harvest, and transport;
  • Be resistant to disease and parasite infestations;
  • Not cannibalistic or territorial;
  • Be readily available as eggs, fingerlings, and juveniles;
  • Have a high market demand;
  • Exhibit high feed conversion rates;
  • Have good dress-out weight values;
  • Have a long shelf life;
  • Be easy to process;
  • Have good eating qualities;
  • Be catchable.

African catfish, Tilapia and Salmon are fish species that are disease resistant in varying degrees; African catfish and Tilapia can tolerate tough environmental conditions compared to Salmon. The cultivation and growth of such species of freshwater fish would limit or reduce losses, improve income earnings and also raise the farmer’s socio-economic standard.

Catfish Farming:

This is the most popular aquaculture business in Nigeria, because of the popularity of the breed of fishes grown. Catfishes are the most common fisheries products used in African meals. Their ease of cultivation and demand makes most aquaculture farmers to focus on growing catfishes instead of other breeds.

Tilapia Farming:

This aquaculture business is run with fresh water fishes inhabiting shallow streams, ponds, rivers, and lakes. Tilapia is the second most popular fish used in Nigerian. The fact that these fishes grow rapidly and tolerate high stocking densities and poor water quality, makes them a lucrative breed for fish farmers to grow.

Salmon Farming:

Salmons or mackerel (commonly referred to as “Titus” in Nigeria) is a fresh water specie of fish that usually migrate to the ocean and return to fresh waters to reproduce. While they are generally harvested in the wild, they are also grown in fish farms.

 

Fish Farming Practice:

  • Monoculture
  • Polyculture and
  • Integrated culture

Monoculture: Only one species of fish is cultured in one or more ponds, by growing either Tilapia or Clarias in the pond(s). The disadvantages are that is underutilization of pond and the farmer having on the knowledge of the management of only one fish variety.

Polyculture: In a culture of this type more than one specie of fish is cultured in the same pond. Fish yield can be high because of proper utilization of feed and less risk of project failure.

Integrated culture: Here fish are reared with other animals and or vegetable gardening. Integrated farming system leads to maximum utilization of space and productivity.

Economics Management:

Economic considerations (in fish farming): can be divided into demand, finance, production, and marketing. The questions listed below are intended to help you plan for the eventual startup of your fish farm business.

  • Do you have sufficient financial resources available?
  • Do you own suitable land with a good source of high-quality water?
  • Do you own enough land and water necessary for a profitable venture?
  • Is there a high demand and sufficient market for your product?
  • Do you have the equipment and machinery necessary?
  • Can you really devote the money, time, and labor necessary?
  • What technology do you have at your disposal and which would be the 
best to adopt?
  • Is expected profit from fish farming greater than other land uses?

Financing is a very important economic consideration. Production economics involve various direct costs, which can be divided into systems costs, production costs, and processing costs.

Systems (Fixed) costs

  1. Initial facilities investment
  • Land (ponds, raceways, wells, ete.)
  • Buildings and equipment (tanks, filters, pumps, nets and boots)
  • Alternative power sources (solar, electrical, fossil fuel)
  1. Maintenance
  2. Depreciation
 of assets
  3. Taxes
  4. Interest on working capital

 

Production (Variable) costs


  1. Fish stock (eggs, fingerlings, spawners)
  2. Chemicals (disease control, additional fertilizer)
  3. Feed
  4. Labor and maintenance cost

5. Water pumping, heating, oxygenation

  1. Fuel (operation and transport)
  2. Other consumables
  3. Consultancy cost (where and when necessary)
  4. Harvesting
  • Equipment (nets, lifts, tractors)
  • Casual labour
  • Holding and/or transport facilities

 

Processing costs

  1. Direct cost to producer
 e.g. transportation to consumer and/or
  2. Transportation to processing facilities

Production Planning

When making a production and business plan for table size fish, one should endeavor to answer the following questions beforehand.

  1. Where is the market?
  • Location,
  • Category of people likely to buy the fish
  1. What does the market want?
  • Type of fish,
  • Quantity,
  • Size,
  • Frequency,
  • Fresh or processed, etc.
  1. What resources do you have?
  • Number of pond(s),
  • Size of pond(s),
  • Water for production (quantity, quality, flow rates),
  • Feeds,
  • Labour,
  • Seed, etc.
  1. From where and when should you source for seed and feed?
  2. What is the quality of feed intend for use?
  • Very important 
because it limits possible Feed Conversion Ratios,
  • Water quality and
  • Carrying capacity.
  1. How much feed and seed would you require?
  2. How frequently do you need to harvest for the market?
  • Complete 
harvest or
  • Partial harvests
  1. How do I get my fish to the market?
  2. What returns can I expect from the above?

Other considerations a prospective fish farmer must bear in mind in starting the project include the following:

Accessibility of the Project Site

The site must be within reach for ease of management and supervision. Such a site will also facilitate marketing of products especially for large-scale operators.

Security

The project site must be kept secured to wade off thieves from harvesting the fish. Site must also be protected from natural enemies of fish like water birds water, snakes, frogs, etc. The pond water should be free from domestic interference and access to cattle.

Labour Availability

Both skilled manpower and casual labourers must be available to manage the pond especially in large fish farms. Farmers should know the nearest location of research and extension staff in fisheries and other service providers. This formation can be obtained from Research Institutes or Fish Farmers Associations that are nearby.

Availability of Inputs

Fish farming inputs include fish seeds (fingerlings), supplementary feeds, fertilizers/manures, and other fishpond accessories. Prospective farmers can and should obtain information from the Ministry of Agriculture on how to source these inputs from the locality.

Planning the Ponds

The assurance of a regular and good source of water supply and land that can retain water (in the case of earthen ponds) for fish culture is the impetus the farmer needs in planning how large the pond should be and how many of a particular unit or units should be constructed. Having done the survey of the land, it is easy to plan the layout of the ponds and channels on paper.

Earthen ponds

The main objective should be to make the best possible use of the land (topography) for earthen ponds at minimum construction cost. Each site will have its own peculiarities and problems and solutions have to be found to overcome them. The following are useful hints in planning the ponds.

  • The shape and size of the pond should fit in with the topography of the land.
  • The bottom of the pond should be sloping to the point close to the embankment where drainage facilities (outlets) will be installed. The water inlet(s) to the pond should be placed preferably at the shallowest end.
  • If more than one pond is constructed it is better to have independent water supply (inlets) to each pond and also separate outlets. By this it would be possible to drain the water from each pond without the water having to flow through a second pond. Such ponds are called parallel
  • Smaller ponds are easier to manage than larger ones. Although a single large pond could be cheaper to construct, the smaller size would facilitate stocking and harvesting programs for the family..
  • Pond depth can vary from 1 to 2 meters. Ponds should not be too shallow or too deep. Shallow ponds can easily be made muddy by action of wind or soil disturbance by human activities. Such ponds also will easily expose the fish to predation by their natural enemies.

Ponds that are too deep will pose management problems to farmers especially during the harvest period. Ponds of average depth of between 1-1.5 meters are suitable for culture of most fresh water species in Nigeria.

Pond construction can be done manually or mechanically. Manual labour can be used if a small size pond is planned or in swampy or marshy area where machines cannot be used. Mechanization (Bulldozer scraper, etc.) is advantageous where large ponds are to be constructed.

 

Construction Estimates depends on the following:

  • Cost of land acquisition
  • Cost of labour to excavate the land, to required depth
  • Cost of construction of pond well
  • Cost of fencing material (for prevention of intrusion)
  • Cost of plumbing materials and accessories
  • Cost of fertilization of pond (fertilizer/lime/manure)

Concrete Ponds

These types of ponds are constructed with concrete materials, and are usually above the ground surface with concrete walls. They are used to raise fish in places where the soil is porous or sandy, house backyards or any available land resource, concrete ponds are more expensive to construct and maintain than earthen ponds. However, earthen ponds are more productive in terms of fish yield.

Concrete ponds are usually smaller than earthen ponds though similar in design. Area of ponds should not be less than 20m2, but ideally 100m2. Larger ponds are usually difficult to manage especially during harvest.

In smaller ponds biotic activities are severely impaired, which in turn hindering fish growth rate, smaller ponds are also prone to frequent water quality problems in feeding and fertilization.

Features of Concrete Pond Construction

  • Well drained upland area are preferred for pond stability, ease of water drainage and to minimize costs considerably
  • To maximize space and save costs “twin” or multiples of ponds are recommended as against constructing ponds singly.
  • Ideal dimension for concrete ponds is 5x4x1.2 m3, if bigger than this, there is need for reinforcement with rods at corners (beams).
  • 9 inches hollow cement blocks are preferred, or 6 inches non-hollow cement blocks.
  • The blocks must be laid to inter-lock at corners.
  • Thorough plastering (1:4) of cement to sand ratio is recommended to safe guard water
  • At least five coaches of blocks must be laid sequentially.
  • Fill the holes in the block with rich concrete mix (1:3:6 of cement, stones and sand respectively) as the 
coaches are being laid.
  • Outlet pipes with screens to be appropriately located at the formulation level, so that complete 
water drainage is insured.
  • Fish Pond constructions work should not be rushed” while upon completion of construction; wait for 3 – 4 weeks for the ponds to be completely “cured”.

Subsequent upon “curing” you can impound with water from available sources – river water, stream, bole hole, well or tap water (Ageing of the water ahead of stocking is pertinent).

 

Construction estimates for concrete ponds depends the size of pond which can be arrived at based on the following:

  • Cost of blocks
  • Cost of cement, sand, gravel and fine stones
  • Cost of plumbing and accessories
  • Cost of Labour
  • Cost of nylon and nettings
  • Cost of fertilization of pond (fertilizer/lime/manure)

In a well-constructed pond, the only water loss should be from evaporation. Pond levels need to be topped up hence the extra water demand. Knowing how much water one requires per cycle helps one size farm reservoir for water supply to fish farms.

Fish Pond Management

An ideal water condition is a necessity for the survival and good growth of fish since the entire life processes of the fish is wholly dependent on the quality of its environment. The pond bottom has a vital role to play on the water quality of the medium because the fertility of the pond is directly related to the size of fish at harvest. Hence, it is imperative that fishponds should be limed and fertilized prior to stocking with fish fingerlings or juveniles.

Liming

It is the application of lime to ponds and it is usually broadcasted. Liming performs the following functions:

  • It serves an anti-parasitic action in water and on an infected fish.
  • It increases the pH of acidic water to more desirable level.
  • It precipitates excessive organic matter in suspension (clay colloids etc) in highly turbid waters, predisposes the water to effective fertilization
  • Liming of ponds predisposed the water to effective fertilization
Name New Ponds Old Ponds
  g/m2 Kg/Ha g/m2 Kg/Ha
  Small Ponds Large Ponds Small Ponds Large Ponds
Agricultural Lime 25 – 50 250 – 500 20 – 30 200 – 300
Quick Lime 75 – 150 750 – 1,500 60 – 100 600 – 1,000
Slaked Lime 75 – 90 750 – 900 50 – 80 500 – 800

Fertilization

This simply means the addition of fertilizers to pond. Fertilizers are of two types – Organic and Inorganic. Fertilization is done essentially to provide basic nutrient components and phosphorous primarily for the rapid development of phytoplankton and zooplanktons. Urea fertilizer must never be used in ponds to effect fertilization.

The following fertilizer application are recommended:

Organic:

  • Cow dung (50 g/m2, 500kg/Ha)
  • Poultry dropping (11-22 g/m2, 110-220 kg/Ha)
  • Pig manure (56 g/m2, 560 kg/Ha)

Inorganic:

  • NPK (22 g/m2, 220 kg/Ha)
  • Triple Super Phosphate (5 g/m2, 50 kg/Ha)

Fish Stocking

After the pond water preparations have been concluded and allow to equilibrate for a minimum of one week, the pond is then said to be ready to “receive” fish. Stocking is usually done in the early hours of the day or late in the evening when the ambient temperature is expected to be cold. The quantity of fish to be stocked is a factor of owner’s financial resources, the size of pond and the level of impoundment that is volume of water. 2 – 10 fingerlings per square meter is recommended.

Fish Feeding

In culturing fish in captivity, provision of well-balanced diets and adequate feeding are very important. If there is no utilizable feed intake by the fish, there will be no growth and the stocked fish may eventually die. An undernourished or malnourished fish is never able to maintain its health and be productive, no matter the quality of its environment.

Fish requires a very high level-protein feed for good growth and development. The desirable protein content of fish feed varies with the stage of growth of the fish and the species of fish in question. The protein requirements reduce with age and size of fish. The provision of good quality feed in adequate and in the right form (powdery/sinking pellets/floating pellets) are very vital to successful fish culture in a controlled environment.

Test Cropping

At the end of the first 2-4 weeks of stocking, test cropping of the stocked pond is usually recommended to ascertain the growth response of fish to the feeds provided, as well as to sort out the shooters among the fish stocked as a way of reducing cannibalism and territorial dominance in the pond water environment.

However, bimonthly assessment of the stocked fish in tanks is recommended to ensure uniform growth as much as possible.

Categories of Catfish Size

Category Length (cm) Average weight (g)
Fry < 7 3
Small fingerlings 7 – 10 3 – 6
Medium fingerlings 10 – 12 6 – 9
Large fingerlings 12 – 15 9 – 20
Stockers   21 – 100
Sub-Market   100 – 399
Table size   400+

 

Harvesting of Fish

Harvesting of fish is usually done using appropriate fishing gears. The type of fishing, gears employed to harvest fish play a significant role in determining the quality of the catch. Also, the size of the water body dictates which fishing gear to employ to get the fish out of water.

Fishes are caught by the use of gill-nets hook and line, cast-nets, seine nets and various immobile traps. In ponds, the use of dragnets, and cast nets predominate over other fishing gears.

Fishing harvesting should be done in the early hours of the day or late in the evening when the ambient temperature is expected to below, so that the microbial spoilage of fish is put in check.

The ‘ideal’ table size for a producer is about 400g because when the fish get to 400g the FCR increases and growth takes much longer. However, if larger sizes can fetch a higher price per kg, you (the farmer) must evaluate the higher cost of production per kg and compare it with the higher price obtained.

 

Production of Table Size African Catfish in Static earthen or concrete Pond without Aeration using Commercial, Nutritionally- Complete Sinking Pellets

In order to achieve a good fish yield (from your fish pond) when fed commercial sinking pellets that are nutritionally complete (i.e. 32% crude protein level with stabilized vitamin C). The following management practices are recommended:

  • Proper pond construction in compliance with 
the recommended standards for commercial grow-out ponds with the necessary depth of water.
  • Pond preparation for stocking inclusive of water intake screening.
  • Use of quality seed and correct stocking procedures.
  • Stocking rates based on ponds carrying capacity in retrospect of the farmers desired harvest size.
  • Feed a quality nutritionally complete feed pellet and feed the fish by response.
  • Maintain good water quality.
  • Inventory control and regular sampling using 
the recommended techniques.
  • Proper record keeping and regular review of 
records during the production cycle.
  • Harvesting at “critical standing crop”, before 
the pond’s carrying capacity has been reached and fish growth slows or ceases

 

Process/Item Recommendation
Pond         i.            Average water depth in pond of 1 – 1.2 meters.
      ii.            Inlet pipe at least 20 cm above the pond water level and screened with a properly fitted filter sock.
    iii.            Outlet pipe fitted with an anti-seep collar and screened correctly with cone mesh.
    iv.            Having a harvest basin within the pond is optional but can be quite useful at final harvest.
      v.            The pond must be able to drain completely for complete harvesting and drying.
Pond Preparation         i.            Earthen Ponds: Remove silt from pond. Soil removed from the bottom should be put back where it came from, i.e., used to repair pond levees. Excess should NOT be put at the top of the dam but rather away from the ponds.
      ii.            Ensure pond is not leaking.
    iii.            Correctly screen the inlet and outlet.
    iv.            Lime the bottom of the ponds, if needed, based 
upon alkalinity and hardness levels (especially of 
new ponds).
      v.            Fill pond.
Stocking         i.            Ponds should be stocked within a week 
of filling with water.
      ii.            Stock based upon targeted harvest size and the pond’s carrying capacity.
    iii.            The minimum stocking size for grow-out ponds should be fish of not less than 10 cm in length or 5 grams average weight. An initial nursery phase of one (1) month, however, is recommended when fish come in straight from the hatchery before the fish are stocked into the grow-out pond. Having an initial nursery phase helps one have better control of the inventory and improves survival rates.
    iv.            The targeted harvest size will be intended market size if you are not following a split production plan.
      v.            The critical standing crop for catfish ponds of an average water depth of one (1) meter fed commercial pellets should be determined
Water Management Static water.

Do not flush water through the pond continuously.

Water should only be added to ponds:

A – to top up water levels, or

B – to correct water quality problems, such as low oxygen, high ammonia, etc.

Note that continuous water flow can be expensive and, the water which is often cold, reduces growth rates. Continuous water flow would thus allow for higher carrying capacity but require more time.

Fish Feeding        i.          Train fish to feed in the same area of the pond.
     ii.          Training fish to feed enables a farmer to see 
his/her fish daily throughout the production cycle. This is of great value when it comes to assessing the number and size of fish in the pond in between sampling times as well as monitoring fish health.
   iii.           Feed fish based upon their feeding response using the catfish feed chart as a guide to estimate daily feeding needs. Pay attention to the number of meals fish of a particular size should be given per day.
   iv.          Keep recommended feeding records including both the amounts given and response at each feed.
     v.          Use the records continuously to evaluate feeding performance in tandem with the pond records to adjust the feeding regime.
Harvesting

 

i.          In order to obtain the best returns, the pond should be harvested

before it reaches its carrying capacity, at critical standing crop.

ii.         The best way to harvest the pond completely is:

Ø  First, check your records and know your 
estimated standing crop.

Ø  Second, seine the pond one or two times to 
remove the bulk of the fish when the pond 
is still full.

Ø  Third, reduce the water level about half-way then seine once or twice to remove the 
rest of the fish.

Ø  Fourth, drain the pond completely and pick 
up the rest of the fish. If the pond has a harvest basin that is correctly constructed, the remaining fish will collect in the harvest basin.

In fish farming enterprises, efficient operation and high production can only be achieved if ponds are properly managed. Management activities begin with the preparation of the pond for the fish crop and continue with stocking and feeding the fish, ensuring that water quality remains high throughout the culture period, taking measures to prevent invasion by predators and the occurrence of diseases, and harvesting the fish.

An important ancillary management practice that should never be overlooked is keeping good records of expenses and income and of all activities and events associated with the pond or farm, so that this information can be used to improve operations in the future.

FARM BUSINESS ANALYSIS

This is often used to show the levels of cost, returns and profit that accrue to a fish farm. Before getting into the business, carefully prepare detailed cost calculation of your proposed fish related farming project. Calculations will be different as per the types of fish you choose for fish farming. Also according to your desired output and total land area.

The profitability of each option is determined to show the strength and weakness of any aquaculture system. It is the difference between the total revenue and total production cost. The revenue includes items such as fish sold, harvest consumed at home or farm, also those given as gifts and change in inventory.

RECORD KEEPING

The collection and analysis of data on cost and returns based on farm records provide among others the following:

  • Help the farmer to establish a number of facts or efficiency standard which form the basic tools of diagnosis and planning
  • Provide the farmer with information on production situation in the farm
  • Provides an effective mechanism for monitoring and evaluating the farm
  • Provide information for appraisal that could show the strength or weakness of management pattern adopted on the farm.
  • Give data that may be used to formulate plans and provide estimates
  • Can be used for meeting some legal/contractual arrangements
  • Add credibility to the claim of many business organizations

There are two types of farm records, these includes daily and seasonal records. Farm records are simply the lists of input and output operations in physical and monetary terms.

A typical fish farm record of how each input in terms of amount, unit and total cost is shown below:

 

Table 1

Date Item Type Quantity Unit cost Total cost
  Variable items
  Fingerlings Clarias/Tilapia      
  Feed Rice bran      
  Fertilizer Poultry manure      
  Water Borehole      
  Fuel (Electricity) Diesel      

 

It is important to also keep records of labour in terms of adult, children, male or female, and wages and payments recorded with duration of labour

 

Table 2

1. Date 2. E. A. 3. Labour 4. Duration 5. Wage rate (Naira) TLC (4×5)
  Pond Preparation Adult Male 3 Man-days    
  Feeding Adult Female 4 hours    
  Harvest Children 5 hours    
        Total  
  1. A. – Economic Activity; TLC – Total Labour Cost

Depreciation

  • Depreciation is calculated from a list of fixed assets with their initial costs and estimated life span using a straight-line method.
  • The cost of the asset divided by its estimated life span gives the depreciation.
  • When salvage value is involved, it is deducted from the initial cost before annual depreciation is calculated. Over the years current replacement cost should be used.

 

Table 3: Depreciation calculation

  1 2 3 4 5 ={4 – 2} 6 7 8 = {5x(7/100)}/6
Item Year Initial Cost (=N=) Current Market Value Salvage Value (=N=) Depreciation Balance (=N=) Estimated Life Span (years) Proportional Usage (%) Depreciation
Pond 2000 50,000 100,000 10,000 40,000 10 100 4,000
Water Pump 2002 25,000 60,000 5,000 20,000 8 90 2,250
Generator 2002 20,000 50,000 5,000 15,000 5 70 2,100
Office 2001 250,000 400,000 150,000 100,000 30 50 1,000

 

Output Records

The following are important items that should be included in output record:

  • Date of harvest,
  • Species harvested, (with amount and unit price) and
  • The disposition of product.

When determining or computing gross revenue on the farm, cash and credit sales of the product should be recorded. In addition computed values of home-consumed products as well as those given out should be recorded.

To get the computed values of the home consumed or those given out, it is advisable to use the current market prices of the fish. It is also important to have a record of inventory at each period of accounting. Thus beginning and closing inventory should be kept.

At the end of each cycle or the year, the quantity and value of production by species and the operation cost by items of each fishpond or a group of ponds in similar conditions should be summarized and presented in a single sheet The purpose of this is to be able to know at a glance the farm’s production situation.

The investment should be fully analyzed to determine the profitability of the ventures using the Payback method, Peak-Profit method, Net Present Value (NPV) method or Internal Rate of Return (IRR).

Example of a production plan outline to rear 2,300 catfish juveniles to table size is shown below. The plan forms the basis of a budget. (Assume ponds have been built)

Item Quantity Unit Cost

(=N=)

Expected Cost

(=N=)

Pond Profile      
Ø Pond Size (m2) (8 x 5) 2    
Ø Average water depth 1.2 m    
Ø Water volume 96 m3    
Water Requirement      
Ø Water need (per month) 1,440 m3 @ 10 per m3 86,400
Stocking      
Ø Expected harvest 1,700    
Ø Target market size 800g    
Ø Number of Fish to stock 2,500 30 75,000
Ø Stocking density 1.8 fish/m3    
Ø Feed conversion ratio (FCR) 1.9    
Ø Survival rate 85%    
Pond Management      
Ø Lime requirement (estimate)      
Ø Fertilizer (estimate)      
Feed Requirements      
Ø Type of feed Commercial Sinking pellets    
Ø Amount of feed required (15kg bags) 125 bags 5,000 625,000
Duration of cycle      
Ø  Weeks 24    
Ø  Days 168    
Ø  No of samplings 5 1,500 6,500
Ø  Final Harvest 5 man days    
Estimated Labour requirement      
Ø  Labour for feedings & maintenance 6 months 20,000 120,000
Ø  Extra labour (sampling/harvest) 7 man days 2,500 12,500
Transportation & Marketing   5,000 5,000
Total Expected Cost of production     930,400

 

The expected harvest is 2, 125 fish (@ 85% survival rate) = 1,700 kg (0.8 x 2,125)

At =N=700 per kilo, Expected returns = =N= 1, 190, 000 (This is 27.94% ROI).

Monitor fish regularly to:

  • Check the general condition and health of the fish.
  • Determine rates of growth.
  • Determine efficiency of feeding (feed conversion).
  • Adjust the daily feeding ration and save on feed costs.
  • Check if stocking rate is appropriate; if too high, crop (out) the bigger fish.
  • Check if stock is reaching target weights and help plan or revise the production or harvesting schedule.

Cost and Returns of Tilapia-Clarias production in a Polyculture farm

No Item Tilapia – Clarias % Of Total Cost
1 Cost Unit Price

(=N=)

Quantity Value
A

 

 

 

 

 

 

 

 

 

 

 

 

B

 

 

 

Operating Cost        
Labour

Feed

Fingerlings

Tilapia

Clarias

Fertilizer

Lime

Other

150

 

150 Man-days 45,000  
Total Variable cost        
Fixed Cost        
 
Salaries

Depreciation

Taxes

Interest payment

       
Total Cost        
2 Production and Revenue output

Tilapia

Clarias

       
Gross Income        
3 Profitability        
Net Income        
Rate of Return on investment        
Production per man per day        
Value of production per man-day        

 

 

APPENDIX

African Catfish

Demand for African catfish (Clarias gariepinus), both for food and as bait in capture fisheries, has been increasing substantially in Nigeria over the years.

Temperature tolerances

  • Temperature is the most important variable affecting the growth of larvae and early juveniles.
  • The optimal temperature for growth appears to be 30°C; however, temperatures in the range of 26-33°C are known to yield acceptable growth performance.
  • At temperatures below this range, growth rates decrease but survival is still good. However, 28°C is the optimal temperature for both yolk sac absorption and maximum growth rate.
  • High temperatures can encourage the growth of harmful bacteria and fungi.

Tolerance of low dissolved oxygen (DO) concentrations

  • Catfish can withstand very low dissolved oxygen levels, but well-oxygenated water is recommended. This is easily achieved by means of aeration or good flow rates.

Salinity tolerance

  • A salinity range of 0-2.5 parts per thousand (ppt) appears to be optimal for young catfish.
  • Larval growth is acceptable in up to 5 ppt salinity, and survival is good up to 7.5 ppt.

Light (Photoperiod)

  • Optimal survival is achieved when larvae are reared in continual darkness, and larval growth decreases with longer periods of light.
  • The free-swimming embryos (hatchlings) shy away from light and are said to be photophobic. They form aggregations on the bottom of the incubation tank.
  • Taking advantage of their photophobic behaviour, it is possible to concentrate them in a dark corner of the tank and to remove both deformed and weak hatchlings using a siphon.

Nutrition and growth

  • Catfish are omnivorous or predatory, feeding mainly on aquatic insects, fish, crustaceans, worms, molluscs, aquatic plants, and algae.
  • They find food by probing through the mud on the bottom of the ponds.
  • Their nutritional requirements in ponds (particularly for protein and lipids) are highly variable, and are influenced by factors such as management practices, stocking densities, availability of natural foods, temperature, fish size, daily feed ration, and feeding frequency.
  • Zooplankton become more important as a diet item with increasing fish size and predominate in the diets of larger fish.

Tilapia

Tilapia grow best in waters with a temperature range of 20-35°C. They can grow up to 500 g in eight months if breeding is controlled and food supply is adequate. Juvenile tilapia feed on phytoplankton, zooplankton, and detritus, but adults feed almost exclusively on phytoplankton.

Temperature tolerances

  • Various strains of Nile tilapia differ with respect to their tolerance to cold, but growth is generally limited at temperatures below 16oC and most strains become severely stressed at 13o
  • Deathbeginstooccurat12oC,withfewfishsurvivingtemperatures below 10oC for any period of time.
  • Nile tilapia do not feed or grow at water temperatures below 15oC and do not spawn at temperatures below 20o
  • The normal water temperature should be 20-30oC, preferably about 28oC, which is considered the ideal temperature for good health and growth. At higher temperatures their metabolic rate rises, leading, in extreme cases, to death.
  • Gradual conditioning would allow tilapia to live within a range of 8-40o

Tolerance of low dissolved oxygen (DO) concentrations

  • Tilapia fish are able to survive levels of dissolved oxygen below 2.3 mg/L as long as temperature and pH remain favourable.
  • In fertilized ponds, a bloom of algae can reduce oxygen levels to as low as 0.3 mg/L with no fish mortality in tilapia.
  • Larger fish are known to be less tolerant than fingerlings; this is due to metabolic demand.

Husbandry

  • Ponds are prepared for stocking in the standard manner for the semi-intensive culture of warm-water fish
  • Fingerlings of 10-20 g are stocked and cultured for a full production cycle (five to six months with fertilization and feeding).
  • Stocking rates range from two to six fingerlings/m2, depending on the level of management.
  • Male tilapia fish are known to grow almost twice as fast as females. It is therefore preferable to stock only males (mono-sex culture) to achieve the fastest growth and reach market size in the shortest possible period of time, resulting in more protein and profit for the farmer.
  • When the fish have reached market size, ponds are partially drained and seines are used to remove the fish. The last fish are removed by fully draining the pond.

 

Concrete Fish Pond [“Tank”]

 

 
Parallel Fish Ponds

 

Definition of terms

Biomass or ‘Standing Crop’:

This is the total weight (mass) of the fish in the pond at any one time. Critical standing crop is the biomass of fish in the pond when the growth rate begins to slow, meaning carrying capacity is near.

Carrying Capacity:

The maximum biomass the pond can hold for production. Growth has ceased at this point, usually due to water quality problems.

Catfish Highway:

Channel along the bottom of the pond levee that catfish dig out and tend to hide in.

Conditioning:

Holding fish without feed for a minimum of 48 hours in good quality water at the hatchery or nursery prior to their collection and transportation to the grow-out farm. The objective of doing so it to allow the fish empty their guts in order to reduce stress to the fish and maintain water quality during transit.

Disease:

This is the manifestation of something gone wrong. Body functions become impaired as a consequence of stress, inherent weakness or infection.

Dumping Feed:

This is placing feed into the pond without consideration of the fishes appetite, feeding response, appropriate feed distribution to the fish nor the consequences of the effect of the quantities fed on water quality. It is often wasteful and results into high Feed Conversion Ratios (FCRs) as well as reduced profitability.

Feed Conversion Ratio (FCR):

The Feed Conversion Ratio (FCR) is the amount of feed it takes to produce a unit weight of fish. It is a measure of the efficiency of feed utilization. It is a critical parameter to monitor as it determines the viability of the enterprise in feed-based production systems.

Feeding Frequency:

This is the number of times in a day fish in a pond are given food.

Fingerlings:

Juvenile fish of 7 cm and above is called fingerling. Fingerlings of 10 g and above are suitable to stock into grow-out ponds directly. Fingerlings of 5 g or less should be stocked into a nursery pond first until they are above 10g.

Flushing:

Replacing a large portion of the water in the pond within a day or less. The objective of flushing a pond is to get rid of excess suspended as well as soluble wastes and to dilute wastes.

Flushing rate:

Usually given as the % of the pond or tank volume per time period OR the volume of water per hour or day

Gasping:

This is when fish come to the surface of the water to gulp in air in situations when dissolved oxygen levels low. For catfish adults, this gulping of air is normal and necessary for them to gain sufficient oxygen. For very small fry, this indicates stressful conditions.

Grow-out Pond:

This is a pond in which fish are reared for table to a size the market requires.

Gutting:  

Removal of the intestines and other viscera from the abdomen of the fish.

Health:

Is the standard or typical condition of the fish, whereby its bodily functions are normal. A healthy fish functions optimally, and is free of abnormalities of stress and disease.

Live Weight Equivalent:

The weight of a whole live fish before it has been processed. Processing fish includes gutting it. Therefore, the term refers to the weight of the fish before gutting.

Nursery Pond:

This is a pond in which young juveniles are reared to the stage when they become fingerlings or stockers. Fish at this stage are extremely fragile and susceptible to predation. Extra attention is consequently given to water quality management and predation control in nursery pond management.

Optimum Ration:

The fish feed that gives the best growth and Feed Conversion Ratio (FCR). There is minimum wastage and minimum deterioration of water quality when fish are fed optimum amounts of feed, which is usually 90% of satiation.

Phytoplankton:

Phytoplanktons are microscopic plants that grow within water. These plants give water its bluish sometimes-greenish colour. Because they are suspended within the water column, they also cause turbidity of the water and subsequently depending on the quantity reduce the depth through which sunlight can penetrate through the water column.

Production Cycle:

This is the period between stocking and draining when fish are being raised in the pond.

Ration:

The amount of feed given or made available to the fish per day. Often expressed as “% body weight per day”.

Sampling:

This is the removal of fish from the pond to assess their growth and health status. After the observations fish are returned to the pond.

Shooters:

These are fish of the same age-group within the same population that grow much bigger than the rest. Often such fish cannibalize on the smaller ones.

Static Water Pond Management:

This is a system of pond management whereby no ‘fresh’ water is allowed into the pond during the course of production except to top up water lost by evaporation and seepage. There is no water exchange in static water pond management.

Stress:

Is an abnormal physiological condition of fish resulting when its collective adaptive responses of the fish to environmental factors approach the fish’s limit of tolerance for that factor.

Stock: 

Generally refers to the fish in production within the pond or on the farm.

Stocking

Putting fish seed into the pond. Stocking the pond marks the start of the   production cycle.

 

 

Grinder Pelletizer

 

 

 

Mixer Dryer

 

 

Good Luck.

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