Chapter 2


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Chapter 2

  1. 1. CHAPTER 2 LITERATURE REVIEW. 2.0 Economic Importance of Fish In the agricultural sector of the Nigerian economy which employs about 70% of the active labour force, fish occupies a unique position in that it is the cheapest source of animal protein consumed by the average Nigerian, accounting for up to 50% of the total animal protein intake (FDF, 2009). With diminishing returns from over fishing in capture fisheries, aquaculture has been growing at some 20% per year since 2003 in Nigeria and continues to attract many investors and new farmers. Fish plays an important role in many areas in Nigeria: a. Economically: Fish is relatively cheaper than other types of meat except pork and is available to Nigerians in fresh, smoked, dried or frozen forms with no religious taboos like pork or beef. - Impact of Agriculture on GDP = 30.8% of GDP (CBN, Statistical Bulletin. 2009) - Impact of Fisheries on GDP = l.0% of GDP, or 3.24% of Agriculture GDP (CBN, Statistical Bulletin, 2009) - Foreign exchange earning potential. This is attained through export of processed (Smoked Catfish/Shrimps) fish and fishery by- products to international markets. - Deficit- With importation of more than 800,000 MT of fish, more than USD 600 million is spent in hard currency and thousands of jobs are exported. - Fish farming can be integrated with smallholder rural agriculture and commercial farms, as well as in irrigation schemes, thereby leading to increased income with improved nutrition.
  2. 2. b. Nutritionally: In 2008, farmed fish contributed some 20% (143,207 MT) of total domestic fish production of 684,575 MT. Availability of fish in rural areas varies but contributes to improved food security. Fish consumption averages 9.8 kg/caput, with total demand for fish at some 1.4 m MT/annum. Nutritionally, among meats, fish is best for human consumption as it is low in fat, calories and cholesterol. Fish consumption is increasing among diet conscious people. c. Employment, Production and Income Generation Fisheries guarantee direct and indirect employment opportunities, with up to 1.6 million artisanal fishermen in the primary sector and some 200,000 workers employed in the aquaculture sub-sector
  3. 3. as shown in .Yields from aquaculture per unit area of land exceed those from agricultural land in terms of economic protein production. 8-18 MT/ha of catfish can be obtained in static ponds, depending on quality of fish seed, fish feeds and management. One well-managed farm of catfish in static ponds, with intensive feeding and close management has yields of 50 tons/hectare. According to the World Fish Center (2009), aquaculture is the world‟s fastest growing food production sub-sector, growing at an annual rate of 8.9% since 1970. Land otherwise not suitable for any other form of agriculture can be used for fish farming (aquaculture) such as Fadama irrigated areas, swamps, spent land, borrow pits. Fish imports reached 937,428 MT in 2008 (FDF, 2008) which costs the country some USD 0.7 billion. Import substitution through aquaculture to eventually replace imports with domestically produced fish could create 70,000 jobs per year. 2. Relevance of Fish Farming A well-organized farmer or investor can enter fish farming and establish a farm enterprise to help reduce risk by diversifying the variety of on-farm activities. This offers a farmer an option to start small and “test the waters”, then, when the business of fish farming is understood and some degree of success has been achieved, the activity can be expanded with more investment and production. The best fish farmers start small and live at the farm and are “hands on” managers who learn to understand the husbandry of fish in water, which is very different from terrestrial farming of animals or crops. Nevertheless, fish farming development is following the poultry industry and is facing similar challenges in its development: 1) the need to educate farmers, 2) the need for quality stocks
  4. 4. of fish of known origins, 3) the need for high quality feeds, 4) the need for record keeping among fish farmers, and 5) the need for quality extension support. This research seeks to present best management practices for fish farmers in Ondo state to follow, along with reasons for success and failure in this dynamic industry by reason of cost benefit analysis. SOURCE: Best Management Practices for Fish Farmers in Nigeria. USAID MARKETS. March 2010. a. Not a get rich strategy Fish farming is not for everyone. It is possible to earn good profit in fish farming, but one should enter into this business with caution, serious planning and a strategy based on a good investigation of the industry and fish farm management. This is done with visits to successful fish farms (Photo 1) and a willingness to learn from participation in good training programmes organized by well-known, qualified groups, NGO‟s or actual fish farmers. One should carefully avoid anyone promoting fish farming as a “get rich quick” scheme, as these types of “consultants” are usually quacks and are unqualified with no practical experience.
  5. 5. b. Need for Best Management Practices- “Fail to plan, plan to fail” This manual seeks to present the best management practices to be used by fish hatchery operators (Photo 2) and fish farmers as well as investors to help them meet with success in fish farming. Investing in fish farming is a serious affair and no one should assume that success is easy. A systematic approach with good record keeping will greatly help the farmer or investor to measure progress in the business of fish farming and to reflect on the causes of success or failure. Note that there are many good technical manuals on “how to do” fish farming and this is not the objective of this document. A number of such manuals are provided in the section on references along with many articles and documents useful to those in aquaculture in general c. Reasons for Failure and Success in Fish Farming In starting this Package of Practices for successful fish farming, it is useful to reflect on why some farmers meet with success while others fail in fish farming. Lessons in success and failure at fish farming were well reported by Isyagi et al (2009), in their Catfish Manual for Uganda and are presented below in Table 3. Table 3 Why Some Fish Farmers Fail in Fish Farming. Adapted from Isyagi et al. 2009. Manual for the Commercial Pond Production of the African Catfish in Uganda. FISH project Uganda. USAID. Coop. 1. No Market: Bad fish farmers start looking for a market for their fish when the fish are ready for sale. Meanwhile, because they are still feeding, the pond attains its maximum loading and fish stop growing. The longer the fish stay in the pond after they have stopped growing, the smaller the profit margin. 2. Poor Farm Siting: Such as in a place with inadequate water supply, poor soils for pond construction (e.g. may be rocky), far away from markets and/or supplies, etc. 3. Poor farm and facility design: Pond dikes not compacted properly, leak a lot, may be too shallow, and consequently construction and maintenance costs become too high while optimum yields are not achieved. Poor accessibility to ponds requires workers to walk across difficult terrain to transfer fish from pond to vehicle or vice-versa. 4. Poor Investment Plan: Several farmers assume that to be a commercial fish farmer one must have several large ponds. Hence, they construct many ponds at once, which constrain their cash flow. Because of this, some farmers take a while to start production or may only afford to start production in one pond after all the investment. 5. Lack of Technical Knowledge: Start production before knowing what management options are available or how to farm fish. 6. Do not employ the right people. Entrepreneurs employ the right people who are qualified for a specific job. Hiring family members who have little or no desire to learn proper fish farming techniques is a liability because most people find it difficult to dismiss them even after it has become apparent that they are the reason for the poor performance of the fish farm.
  6. 6. 7. Absentee Owners/Managers: Manage farms by remote control or telephone. No direct involvement in production and management activities of the farm. 8. Irregular and improper feeding: This ranges from complete lack of knowledge about the nutritional requirements and feeding of catfish to attempts at saving money by using cheap feeds. Some farmers just do not feed their fish because they think fish will grow as long as they are in water. They do not realize that like all animals, best performance would be obtained if the fish have a balanced diet and that the feed needs to be palatable, easily digestible and does not disintegrate into the water before the fish can consume it. Fish should be fed with the correct feed of the right quality by a conscientious person who is aware that fish should be fed according to feeding response. Fish may not always feed with the same intensity. They may not want to consume much in bad weather or with a sudden change in temperature; fish may also not eat when they are sick. 9. Fail to Use the Best Person for Feeding: The person feeding fish should be conscientious and keen to observe the fish and know their habits. Feed is not to be dumped into ponds or tanks, but fed according to the fishes feeding response. Feed is expensive (up to 60-70% of operating cost) and only the best laborer can obtain a low feed conversion and lowest cost. 10. Does not understand management regimes: Do not appreciate that different management levels have different requirements which consequently affects stocking rates. Stocking rates are a function of the specific management regime. 11. Focus on few large fish rather than Volume Production: Being more impressed with harvesting the few large fish rather than looking at the overall picture and appreciating total tonnage at harvest. Survival rates and average fish size matter when raising table-fish, because profit margins above operational costs generally range between 10 to 30% depending on one‟s market. The net income is therefore largely a function of turnover. 12. Do not keep records and do not assess performance to re-adjust management practices accordingly after each cycle. A farmer is therefore unable to tell whether a profit or loss will have been made. Having money in one‟s pocket after a sale does not imply one has made a profit. Records must be kept on all aspects of management to help the farmer evaluate and correct his/her management practices, for improving production and putting together a business plan. 13. Hobby farmers who fail to harvest at the correct time, as though they are taking care of wild-life in a game park. 14. Wrong objectives for investing in aquaculture. Some do it simply because their friends are doing it or because they are targeting „free‟ funds from donors or government. Nothing in this world is free. Always watch out for the hidden costs before making a final decision. Furthermore, pond or tank construction is costly and is not something one should undertake for the sake of it. Think objectively before you embark on fish farming. Embark on fish farming as a business as a source of employment and income for yourself and others. Invest in fish farming only if you have studied it and understand the challenges. 15. Expand the farm as a solution to low profit and yields. It is a bad business decision to expand a failing business without first finding out what the causes of the failure are and correcting them. 16. Believe consultants and newspaper reports that indicate fish farming requires little investment and results in huge profits. If it were that easy, everyone would be doing it. And the so-called consultants would be busy making money from growing fish; not from advertising their expensive training programs. Why some Fish Farmers Succeed 1. Know their Market before Starting Fish Farming: Identify their business opportunities and markets beforehand. 2. Know the Market Demand: Tailor their production to meet the market requirements in a profitable and reliable manner. 3. Invest wisely, step-by-step. Start small and build up only if they are making profits. Do not think of expanding (build more ponds for production) if when they realize they are making losses. 4. Seek Advice only from Proven, Qualified Advisors: Are particular about where they source advice from and whom they select as advisors. Select those with a proven track record, who have been vetted by professional organizations. 5. Do not cover up their mistakes but rather learn from them as well as from other farmers‟ mistakes. 6. Keep and use their records as management tools. Track their expenditure and losses. 7. Follow recommended Best Management Practices. 8. Use the best feed locally available to them correctly; closely monitoring their Feed Conversions and cost. 9. Owners are Managers: Owners are involved in the running and/or management of the farm. 10. Market Driven Management: Invest and manage their farms based on the market opportunities and their resource limitations. 11. Proper sitting of the farms and adopt appropriate production technology. 12. Sell their fish to the market as soon as they reach market size and appreciate turnover.
  7. 7. 13. Honor promises to their customers, even if occasionally it means they may have to make a no-profit sale or replace fish at no charge. 14. Are able to analyze their farm data themselves and use the data they obtain to assess the farm‟s production and economic performance. 15. Use their own data as the primary basis for making management and investment decisions. 3. Types of Aquaculture Production Systems in Nigeria Nigerian fish farmers use a variety of production systems with different levels of investment, different management requirements and production potentials. Thus farmers have several options for entering fish farming depending on their physical and financial resources. With consumer preference clearly favoring catfish, commercial fish farming remains largely focused on this species, with only a few farms raising tilapias. However, tilapia production is expected to increase. A. EARTHEN (STATIC) PONDS AND HOMESTEAD TANKS The early colonial period efforts at fish farming involved tilapia and carp farming in earthen ponds in areas where water was available through the water table or from flowing streams. A number of these ponds remain in production today following their rehabilitation, including removal of deep bottom mud. Early efforts lacked quality fish seed and feeds and pond production cycles were allowed to run up to a year or more. With infrequent harvests, ponds were not drained regularly and this resulted in accumulation of deep bottom mud, of high organic content limiting use and production in such ponds. Poaching of fish was also a major problem with earthen fish ponds. In the 60‟s and 70‟s, there was a homestead fish farming programme but it lacked good technical support, had limited availability of fish seed and quality fish feeds were not available during this period. In the homestead programme, thousands of concrete fish tanks were built in backyards with fish production centred on tilapias, but also including carp and catfish. However, most of these tanks of some 30 m2 area each were poorly maintained and did not result in significant contribution to supply of fish. Many such tanks were used by hobbyists, who enjoyed having a few large fish to show their
  8. 8. friends. Concrete tanks built during this early period also encountered problems with accumulation of wastes and algae as many were deep (2-3 m) and built into the ground to maintain cooler water in favour of the carp which were imported from Austria. Such conditions complicate routine sampling and harvest activities; they also had a negative impact on water quality as build up of decomposing organic matter and wastes may increase toxic ammonia levels and lower oxygen content in the water column. Such conditions stress fish resulting in slow growth. Furthermore, rich organic conditions may harbour disease and parasites. SOURCE : Best Management Practices for Fish Farmers in Nigeria. USAID MARKETS. March 2010. B. TANK FLOW-THROUGH FISH FARMING-CONCRETE BLOCK TANKS Many of the homestead tanks were abandoned. Nevertheless, the idea of using such tanks led to today‟s fish farm estates and fish farm villages where many fish tanks are used through cooperative management for high catfish production (Photo 4). Theft of fish is easily controlled in complexes of
  9. 9. well-supervised tanks, which were built above ground with concrete blocks. Facilities are established for pumping of water to flush out wastes and foul waters from tanks on a regular basis. With use of high quality fish feeds, very high fish productions are obtained in such tanks. Many fish tank owners have 2-3 contiguous tanks of 16 m2 each from which they are known to produce up to 1.5 tons of catfish per year in these semi flow-through systems. C. RECIRCULATION SYSTEMS Some 100 recirculation aquaculture systems (Photo 5) have been constructed in Nigeria and have application in situations where water supply may be limited or irregular. Such systems use bio filters to remove ammonia and maintain oxygen at satisfactory levels. The systems are very high tech and require 24 hour, seven day a week sophisticated management with constant use of pumps requiring constant electricity. The same water is recycled continuously with replacement of 5-10% of the volume daily to cover for evaporation and other loss. With the highly variable availability of electricity from the National Electrical Power Authority (NEPA), most individuals and the private sector are forced to invest in costly purchase of generators, which cost ten times more to operate than the cost of NEPA. The high cost of electricity has driven some owners to close their recirculation fish farms, while others have reduced use of electricity to maintain oxygen levels and to flush waste out of the tanks. D. EARTHEN PONDS WITH AERATION Most fish farmers do not use aeration in Nigeria due to the limited, irregular availability of electrical supply. This is unfortunate as use of aeration could greatly increase production. As mentioned, use of generators can be ten times more costly than use of the national electrical grid. A
  10. 10. few farms installed different types of aerators, but had to curtail their use due to excessive cost. Paddle wheels (Photo 6) are used to circulate water in a few farms in Nigeria; however these have mechanical and electrical problems and high operating costs. With improved management, use of low amperage blowers and aerators could increase production and profit at low cost. E. CAGE FISH FARMING Cage fish farming has been researched in Nigeria since the 1990s, but no commercial fish farm has been developed around use of cages as production units, even though these have met with commercial success in Zimbabwe, Ghana and Uganda. Theft of fish and problems with longevity of materials used in building cages was a problem in trials of cage fish farming by an IFAD-assisted artisanal fisheries project in the 1990s. Presently efforts are underway to launch commercial cage fish farming in the SW. With good water exchange, cages with tilapia in Uganda have produced 180 kg/m3 of cage (FISH. 2006). D. NEED FOR SPECIALISATIONS There is a need among farmers to reduce costs and this has brought many fish farmers to start producing their own fish fingerlings and their own fish feeds and to process their own fish for value addition as with smoked fish. Thus many farmers have invested in equipment for hatcheries, feed milling and fish smoking and to do this they have also invested in a costly generator. The feeds they produce are usually not of the high quality needed for water stability and rapid fish growth. The farmer who started out to produce table fish has felt forced to take on many other activities for which he/she is not well qualified to do. Such vertical integration of a fish farming operation requires resources which most small to medium scale fish farmers‟ lack. Clearly Nigerian fish farmers need
  11. 11. to return to their roots and produce whatever they are best qualified to do with their resources. And if it is to produce table fish, they should thus purchase their fingerlings from a well-equipped hatchery which has quality brood stock of known source, and purchase fish feeds from the best locally available feed mill. This mirrors how aquaculture development has occurred in Asia and it also helps develop an extended value chain. This also calls for good record keeping as most farmers do not really know if they are making profit. As shown later in this document, farmers can often make more money using high quality, more expensive fish feeds than from using feeds produced on-farm or from a poor quality, lower cost, locally made feed. 3. Site Selection Criteria Many investors and farmers enter into fish farming with no consideration for how or where they are going to market their fish. But this is the first factor that should be considered in selecting a site for a fish farm. Is there a good market for fish in the area? A well-informed investor should not only know of the presence of markets in the area, but of their sales capacity for fish. In other words the wise investor would investigate the market and have an idea of how many fish he could sell there on a daily basis. This market awareness could help the investor in designing his fish farm and the size of ponds. If a pond is harvested, there should be an immediate market for all the fish. Holding fish that have reached marketable size is costly to the farmer. a. Markets Most fish markets in Nigeria display live catfish for sale held in tubs and various basins. The choice of the hardy African catfish responds well to the limited conditions in which ice and refrigeration are unavailable. Catfish can be held for days at high densities in limited volumes of water in tubs in the market. Sale of live fish is common with consumers taking their fish home only to place them in a
  12. 12. bucket of water alive till they are ready to cook them. With few refrigerators in homes, this live marketing system works well for the fishmongers and buyers. Such a system is not possible with tilapias. As input costs rise (feeds, energy, and transport) and the selling price of fish remains the same, fish farmers are forced to find ways to reduce costs. Many farmers try to find cheaper feeds as this represents up to 60-70% of operating costs. Some imported feeds are losing favour as farmers are taking more seriously use of locally manufactured, high quality, fish feeds. Farmers also try to improve survival of their fish and reduce injuries through improved handling to improve the appearance of their fish. Some farmers in the SW have found better markets for their fish in the SE or North, where fish sell for some 600 N/kg compared to 400-450 N/kg in the SW. Other farmers are trying to sell their fish at retail prices to eliminate intermediaries; others seek to add-value by smoking fish for markets in the North. This alleviates the seller from having to hold fish and it extends the shelf life of the processed fish. The cost structures in marketing of captured fish and farm-raised fish are different and marketing of farmed fish is usually apart from fish sourced in capture fisheries. With over fishing in rivers and lakes, catfish from the wild (termed “Eja odo” in Yoruba or River Fish) are generally very small (0.3-0.6 kg). These “God-given” fish are considered tastier by some and sell for N300/kg. These fish are usually smoked. Farmed raised catfish are termed “Agric fish” and are much larger (1-2 kg) than wild-caught fish which are subjected to over fishing, causing decreasing size of fishes. Farmedraised fish sell for N400-450 in the SW, but fetch N600 and more in the SE and North. There may be gradual shifts in market trends and distribution of fish for sale, but given the present separation of markets in Nigeria, interconnection of these markets is not anticipated. Today, many fish farmers enjoy high demand and most fish are marketed at the farm to intermediate buyers. Still, fish farmers
  13. 13. often complain of having a poor market for their fish. With market diversification underway into semi luxury products and growing fast food markets and the need to professionally process fish, it is anticipated that fish farmers will face a changing market structure in the near future. If farmers want to increase their margins, this could be facilitated by farmers forming marketing cooperatives, as has been done in Uganda and elsewhere. If modern live fish transport techniques can be employed, live fish could be transported in large quantities to be sold in better markets in the North and SE. By reducing the number of intermediate fish buyers, farmers could gain more control of their market and also benefit from a stronger profit margin in spite of increased input prices. Some State Governments are trying to assist farmers in marketing by setting up fish kiosks as markets for fresh fish. b. Water availability and quality Not just any water is satisfactory for fish farming. Water should be unpolluted and without risk of contamination for fish farming. Is there sufficient water available to manage the farm year round? A water budget is needed to calculate how much water is required for a given fish farm. Water budgets
  14. 14. should consider water loss due to seepage, evaporation as well as filling the pond perhaps twice during the year as required to replace water lost from harvests. Seepage depends on the quality of soils in the area and can be estimated by digging a hole of about a meter in depth and filling it with water till the soils are saturated. A stick can be placed in the hole and marked at the water level and water loss will indicate seepage for the given soil type. Evaporation varies with the location, seasons, temperatures and wind but can be estimated using climatological data. Many areas would have evaporation of at least a meter per year, but this will vary a great deal. Moehl et al (2006) recommended an allowable water loss to seepage and evaporation of 1-2 cm per day, although hot windy conditions in hot, arid areas may greatly exceed this. The water required for filling and refilling the pond, as needed at harvests, can be calculated easily by determining the volume of the pond. An example of a water budget for a fish pond is shown in Figure 2 and summarizes an inflow of 1.8 litres/minute which equals 0.75 litres/minute/100 m2 of pond. Note that if a site without seepage is used, the water requirements are greatly reduced. Inflowing water to a pond can be quantified by use of a bucket of known volume and determining how much time is required to fill the bucket. Water quality is discussed later with parameters presented in Table 5.
  15. 15. c. Quality of Soils for Pond Production Systems Soils need to be impermeable for pond construction. Clay should make up at least 20-25% of the soil; in testing the soils, one should be able to make a ball with the soil that should stick together when tossing it in the air several times. Clay soils are plastic and stick together when pressed between the fingers. Such soils have great expansion capacity as shown with cracks when they dry out. In building ponds, the arable top soils with organic matter should be moved aside to be placed on top of the dikes and sown with grasses for ground cover to prevent erosion. 4. Pond Construction Methods Proper pond construction is essential for achieving good, profitable fish production. Ponds must be of the proper depths and dimensions as determined in part by the market demand. Up to some 1.5 m in depth, the deeper ponds produce more fish; a good maximum water depth is about 1.2 m. Ponds are not dug, they are constructed. Ponds may be constructed by hand labour or by use of bull dozers and other heavy equipment. The best management begins with well-built ponds or tanks. Ponds should have gentle slopes on dikes as depicted in Figure 1; these require minimal maintenance and
  16. 16. facilitate sampling and harvest of fish from the pond. Pond construction involves staking out pond dikes (tops and bottoms) and respecting the design of the pond as regards depths and heights of dikes. Earth used in pond construction should be compacted in layers of 15-20 cm. Work crews involved in building ponds require close supervision to ensure the pond is constructed right the first time around. Poorly built ponds may leak and cost the farmer money in low productions and high water use. The most efficient pond construction involves digging only as much soils as are required to build the dikes. In other words, “cut should equal fill.” Aquaculture (fish farming) activities can be carried out in earthen ponds, concrete tanks or a combination of both. To select sites for commercial fish production, attention should be given to cost of construction and cost of operation (i.e. economics of feeding and harvesting). An earthen pond cross section is presented in Figure 1. Some ponds are built in swamps and low-lying areas where the water table is near the surface. Such ponds often cannot be totally drained. Ponds should not be built in such areas and be built above the water table as ponds within the water table cannot be drained at will; a fish farmer should be able to drain his pond anytime as needed. Water entry and outlets should be by gravity flow and at the same location. A minimum of 1.5 m is required between the level of water supply and the drain
  17. 17. To facilitate harvest of fish, a harvest or catch basin is recommended. Pond construction is expensive and this has led many entrants to fish farming in Nigeria to build concrete tanks or to buy plastic tanks as production units. These are smaller units but are believed to be easier to manage as production units. Nigerian farmers have limited land and tank fish farming adapts well to their conditions, than larger, more expensive earthen ponds. It is also noted that the quantity of fish harvested from such smaller production units is more easily marketed than harvests from large fish ponds. a. Manual Labour Many ponds are built by hand labour and specialized work crews are now building ponds in some areas. With good supervision, they can be built to high standards with high functionality for easy management and harvest. Some 40 man days of labour are required for each 100 m 2 of pond area when using hand labour. When building pond dikes, it is necessary to compact fill soils in dikes in 15-20 cm layers to avoid seepage problems. Field trials in Uganda have shown that farmers with deeper ponds achieve greater fish productions. Some ponds are relatively shallow with maximum depths at 50 cm to 75 cm and this may result in stunted fish and facilitate bird predation. In Uganda, Isayagi et al (2009) recommended a depth of about 1.2 m should be in the deeper waters. It is
  18. 18. advised that the inlet and drain be at the same location in the pond (see Figure 3) as this will facilitate harvest. An incoming water supply above the drain area or catch basin can help reduce stress on fish during harvest. A photograph of a catch basin is shown in Photo 11; such a basin can greatly facilitate harvest of fish. b. Use of Earth Moving Equipment Use of bulldozers can greatly speed up pond construction. A D-6 bulldozer can move some 50-60 m3 of earth per hour and can construct ponds very well in a short amount of time. However close supervision by a specialist in use of heavy equipment for pond construction such as an engineer is required; topographic surveying is also required during all pond construction to ensure proper depths and slopes are achieved. Dikes made with gentle slopes of 2:1 to 3:1 cost a bit more but avoid maintenance problems over time. Best Management Practices for Sitting of Fish Farms and for Pond Construction A summary of best management practices for identification of sites for fish farms and for pond construction is presented in Table 6. Table 5. A summary of Best Management Practices for Siting a Fish Farm and Pond Construction. 5. Suitable Fish Species for Farming Note that the best fish for farming is one that does not reach sexual maturity until after reaching market size. The preference for catfish by consumers has determined the main fish for farming in Nigeria. Fortunately, Clarias catfish reach sexual maturity at some 600 g or more average weight, so
  19. 19. all food consumed by the fish to this weight goes for growth in body meat and not gonadal development. The preferred market size in most markets is around 1 kilogram. The Heterobranchus bidorsalis is another favoured catfish in Nigeria which can be crossed with Clarias to produce a “Heteroclarias” variety which is said to be faster growing than the parents. These fish are preferred in the SS states, while consumers in the SW prefer the popular Clarias gariepinus. Most markets seek larger fish so fish farmers seek to raise fish to one kilogram fish or more, but in some areas, demand is for smaller fish. Some consumers say the older, larger fish taste too oily or have a taste of bottom mud, whereas the smaller, younger fish are sweeter. To some extent the same applies to tilapia – Oreochromis niloticus. A few common carp, Cyprinus carpio, can be found in Nigeria and the “mirror carp” variety also exists along with grass carp, gold fish and koi carp. Other carp have been introduced but are no longer easily found. These fish grow very fast but have “floating bones” in their flanks (filets). There is a small ornamental fish industry in Nigeria, for export of indigenous species of Cichlids, Cyprinids and a variety of catfish and other local species.
  20. 20. SOURCE: Best Management Practices for Fish Farmers in Nigeria. USAID MARKETS. March 2010. 6. Feed Quality: “The high cost of cheap fish feeds”. a. High Quality Fish Feed Manufacture The best fish feeds produce the highest productions with limited environmental impact. High quality fish feeds are manufactured through extremely fine grinding, blending, conditioning and high temperatures (55- 65oC), which de-toxify some compounds in feed components (as with soy beans, cotton seed meal and ground nut meal) to make all nutrients more available for consumption and efficient digestion by fish. The high temperature gelatinizes starches to add binding properties creating pellets having physical strength as noted by water stability. It is the sudden release of the high pressure and subsequent rapid expansion of the pellets as they pass out of the die that creates floating pellets (Jauncey, Sorensen and Areola, 2008). The best manufactured feeds receive an oil coating as shown in Photo 17, which makes them more desirable and palatable to catfish. Soy beans are one of the best plant sources of amino acids and are an important ingredient in most animal feeds, however, they contain anti nutrients that need to be transformed though cooking at high temperatures and pelletisation. Fish feeds are fed in water and therefore must be stable in water for at least 15 minutes, to remain together for complete consumption of each pellet by fish.
  21. 21. b. Fish Feed Formulation Criteria Jauncey, Sorensen and Areola (2008) presented comprehensive information regarding fish feed formulation and feeding husbandry. Generally catfish feeds for fry contain up to 50% crude protein (CP), and their recommended level for fingerlings is 46% CP, with juveniles being fed 42% CP while growers receive feed rated at 38% CP. Of course the smallest pellets are fed to larvae and fry and pellet size or diameter increases with fish growth. Proximate analysis of catfish feeds should meet the following criteria: - Crude Protein – 38-50% depending on size of fish; some sources indicate levels at 32% for growers - Energy - 8.5-9.5 K calories/gram of protein - Fats - 4-6% increasing as protein increases - Carbohydrates- 20-35% - Fiber - < 4% Jauncey et al (2008) gave a good review of possible fish feed ingredients
  22. 22. c. Fish Feed Conversion Ratio A smaller quantity of high quality fish feed is required to produce one kilogram of fish than poor quality feeds. The ratio of fish feeds to gain in weight of fish is called the Feed Conversion Ratio (FCR) and is expressed as, for instance, 1.5 : 1, which is to say 1.5 kilos of feed are required to achieve one kilo gain in weight of fish. FCRs are used to compare the cost effectiveness of feeds as shown in Table 6. d. Water Stability Requirement Quality fish feeds must remain intact or be structurally water stable for at least one hour. Poor quality feeds have little water stability and start fragmenting and “falling apart” soon after entering the water. Such feeds may not be consumed by fish and thus become pollutants in the pond or tank. Many of the artisanal fish feeds made on-farm fall into this category. Farmers may invest in a dry pelletizing machine and produce a smooth pellet, but it crumbles easily and has no stability in water. Other farmers make their fish feeds using a cooking process with wet pelletization for sinking pellets; cooked feeds have better structural strength for water stability be they sinking or floating. However, such feeds made “on-farm” are often poorly dried retaining moisture greater than 10%, causing the feed to rapidly become mouldy and unfit for feeding fish. Some local artisanal feeds may contain vitamin C, but of the unstabilised quality which is largely destroyed in processing. Some fish farmers claim some imported feeds or feed ingredients have caused disease problems. as was reported by Jauncey, et al, (2008). The industry obviously needs to put in place quality control measures. e. Which type of feed to choose?
  23. 23. For some years, fish farmers in Nigeria have preferred high quality imported fish feeds, going along with the common belief, “if it is imported, it has to be better than locally made products”. However this preference is changing as the cost of imported feeds has increased and now high quality, lower priced locally manufactured fish feeds are becoming tested and proven by farmers. Increasingly such feeds are available and farmers are benefiting from their use. In spite of this, perhaps as many as 50% of fish farmers still make their own (artisanal) fish feeds (Aquaculture Director, Federal Department of Fisheries, pers. comm., 2010); some use high quality imported feeds for the first two months of growth, then switch over to their “home made” feeds. Many of these farmers do not keep records and fail to grasp their total expenditures and economic results be they positive or negative. By investing in low-cost feed milling equipment they feel they can save money but fail to realize the cost of their total investment in not only inferior equipment but also in a generator as they cannot rely on the national electrical grid of NEPA. One small fish hatchery operator was paying N118/hour to operate his generator while the same farmer stated his NEPA costs were only N8.3/hour. f. Opportunity Cost Added to these costs are the lost opportunity costs. Use of poor quality fish feeds may add 1.5 to 2.0 months to the production period as the fish grow more slowly. So the farmer may only obtain 1.5 production cycles per year instead of 2 to 3 with high quality feeds. Even if the poor quality feeds produced similar yield per cycle, the high quality feeds could have up to 50% greater annual production. This translates in significantly higher yields and offers the farmer much higher revenues, showing the “high cost of cheap fish feeds”. A comparison of cost effectiveness of artisanal fish feeds made on-farm with a locally produced high quality fish feed are presented below in Table 7.
  24. 24. Table 7. Comparison of cost effectiveness of artisanal and manufactured fish feeds. March 2010. These results show the high quality, more costly feed to actually produce a kilo of fish at N104 (USD 0.70) less than the cheaper feed made on the farm. This is significantly less expensive. On an annual basis more profit could be gained with the more expensive feeds because of the shorter production cycle, which allows more production periods during the year than the less expensive feeds which have a longer growing period. Farmers should judge fish feeds on performance and not simply cost. 7. Pond Carrying Capacity Each pond has a carrying capacity or production capacity based on species of fish, water quality, temperature and quality of fish feeds. All agricultural activities have such a carrying capacity. A maize farmer would space planting his seeds at certain distances apart to allow for maximum production; too many seeds planted too close together would produce a small crop. The same is true for fish. Under the best of conditions in static earthen ponds in Nigeria, catfish productions of 10-12 tons per hectare have been achieved although some farmers claim productions up to 50 tons per hectare. This is possible as Asian catfish farmers achieve productions up to 200 MT/ha/year. For yields of 50 MT, it is necessary to stock ponds with catfish at a density of 6 fish/m2. This would assume a mortality of up to 20% and harvested fish averaging about 1 kg each in weight. Still many ponds are routinely stocked at 5-10 fish/m2. During rearing of juveniles, densities may be 50 fish/m2
  25. 25. or even more as their density would be reduced upon stocking in production ponds. Many fish farmers rearing fish in concrete block tanks stock fish for grow out at 15 to 30 catfish/m2 and achieve total productions of 750 kg in six months from 3 tanks of about 50m2 total surface area. This extrapolates to a production of 300 MT/ha/year, but this is by using the tanks in a partial flow through system to remove wastes and foul water with regular flushing of water. The less hardy tilapias cannot be stocked at such densities as Clarias as their tolerance for limiting conditions of low oxygen and accumulation of waste are very limited in comparison with catfish. Table 8 presents the factors that must be brought together to create a successful fish farming enterprise.