The long–term objectives of aquaculture development in Thailand are intended, in general, to maximize the production of aqua–farms and to establish and economically viable industry with the view of increasing employment, generating the development of anciliary industries and increasing foreign exchange earnings. In order to achieve these objectives, marine shrimp and freshwater prawn (Macrobrachium rosenbergii) culture have been selected by the government as two of the most important species for development.
Freshwater prawns including many species of Macrobrachium, have been commercially harvested in the lakes and rivers in Thailand. The annual catch from natural waters peaked in 1974 but has declined since then (Annex 3). To satisfy the local demand, Macrobrachium is now being imported, mainly from Burma, at an amount of at least 150 tons annually (see Section 3 of this report). The high demand for this species, both locally and abroad, and the success in developing techniques for both post-larvae production and grow-out systems for Macrobrachium rosenbergii has stimulated the rapid expansion of freshwater prawn farming in Thailand. Current statistics indicates that the freshwater prawn industry in Thailand consists of about 59 hatcheries and at least 455 farms utilizing about 2,346 rai (375 hectares) of agricultural land. Freshwater prawn farming in Thailand is already on a larger scale than in any country including Hawaii.
Unfortunately, little is known and documented concerning the economic aspects of this growing industry in Thailand except one case study (Wetchgarun and Uraironk, 1980). The economic analysis of this industry is important for intended investors as well as policy makers. The purpose of this section is to evaluate the economic status of large, medium and small hatcheries and grow–out farms for Macrobrachium rosenbergii in Thailand.
Economic data used in this section were collected mainly from a field survey of hatcheries and farms in various sizes (see questionnaires in Annexes 4 and 5). The samples were selected randomly from a list of hatcheries and farms prepared by a government fisheries station. Because of the time limitation coupled with the flood problems during the period of this study, many farms, especially small ones, could not be visited. Among the hatcheries and farms interviewed, only 9 hatcheries and 14 farms provided enough data for economic evaluation. The hatcheries interviewed are located mainly in the Chacheongsao province, while the farms visited are scattered in the areas of Chacheongsao, Suphanburi, Nakornsawan, and Chiang Mai.
Culture practices and economic status of hatchery operation and of grow-out farms are assessed separately in this report. Since the details of culture practices are described in another paper (New, et al., 1980), only brief reviews are provided here.
The number of freshwater prawn hatcheries in Thailand increased from about 12 in 1978 to 59 at the present time while the annual production increased from 2.6 million post–larvae to about 26 million (Annex 6), with a potential production of over 100 million annually. Among these hatcheries, there are two government owned hatcheries - Chacheongsao and Songkhla. Chacheongsao Fisheries Station, producing and distributing post–larvae and also providing training and extension work in larval and post–larvae rearing, plays a major role in stimulating the expansion of the industry. Post–larvae produced in Songkhla Fisheries Station are mainly for stocking in pens in the Songkhla Lake and also in ponds in the surrounding area.
Out of the 59 hatcheries, 64 percent are small, with an annual production of less than one million post–larvae, 31 percent medium and only 3 percent large. Nearly all of the small hatcheries and some of the medium ones are inland rather than on the coast. The sea water required is either transported by the hatchery operators or purchased from a supplier. A salinity of 12 ppt is generally used. Fresh water is obtained from tap water for most of the small hatcheries and from wells for the large ones. Gravid female prawns (brood stocks) are obtained from the rearing ponds or from natural waters. The facilities used for larval rearing are mostly concrete tanks. A variety of larval feeds are used including Artemia nauplii, and prepared feeds consisting of fish flesh, mussel flesh, egg, etc. The estimated survival rate of juveniles is in the range of 10–50%. Each production cycle lasts about 30–40 days. Actually, 10 cycles a year can be produced, but many small hatcheries stop producing during the dry season months (February-May) when the demand for post–larvae is relatively low because of the shortage of water for the rearing ponds. Post–larvae are transported by road, rail and air throughout Thailand. Inflated plastic bags containing water are usually used.
Initial investment in a hatchery ranges from less than ฿20,000 ($1,000) for small to ฿250,000 ($12,500) for medium and to more than ฿1,000,000 ($50,000) for a large size units (Annex 7). Breeding and nursery tanks, water storage tanks, pumps, the air blower, generator, pvc piping etc., are the major cost items.
Annual operating costs are high when compared to initial investment. These account for about 5.6 times the initial investment, on the average, for small size hatcheries, 1.8 times for medium size and about the same amount for large ones. Feed (mainly Artemia), labor and sea water are the major operating costs, jointly accounting for about 69, 57 and 42 percent of the total annual operating expenses, respectively, for small, medium and large hatcheries (Annex 7). For large hatcheries, depreciation on facilities and equipment and interest on initial investment are also important cost items which jointly account for about 30 percent of the annual operating expenses.
All of the hatcheries interviewed are doing well from an economic point of view. Annual profits range from about ฿44,000 ($2,200) for small hatcheries, to ฿392,000 ($19,600) for medium size and to about ฿744,000 ($37,200) for the large ones. Small hatcheries have the highest rate of return on initial investment (236%), mainly because of their low initial investment, followed by medium (154%) and large (62%) hatcheries. These figures indicate that the initial investment can be paid off within the first year of operation for small and medium size hatcheries and within the second year of operation for the large ones. The rate of return on operating cost, however, is much lower than the rate of return on initial investment, except for the large hatcheries, mainly due to high annual operating expenses.
On average, the cost of production per 1,000 post–larvae is estimated to be about ฿230, ฿180 and ฿200 ($11.5, $9.0, $10.0) for small, medium and large hatheries, respectively. Medium size hatcheries have the lowest cost of production per unit of output and appear to be more efficient in production at the present time. Small size hatcheries tend to use more feed and labor per unit of output while large size hatcheries have high overhead costs.
It is important to note that the cost of production per 1,000 of postlarvae can be ฿40–50 ($2.0–2.5) less when the hatchery is located near the sea, mainly because of the saving on sea water. Also, an integrated hatchery operation and grow-out pond production would reduce the cost of production of both post–larvae and marketable prawns. Labor, facilities, and equipment can be shared by each operation and can be used more efficiently. For instance, a case study of an integrated hatchery and pond operation in Annex 8 indicates that the cost of production per 1,000 post-larvae is about ฿120 ($6.0), compared to ฿180–230 ($9.0–11.5) for those hatcheries without their own growout ponds, while the cost of production per kg of marketable prawns is about ฿49 ($2.45), compared to ฿59–90 ($2.95–4.50) for those farms without their own hatcheries.
The survival rate of juveniles from hatching is very low (as low as 5–10 percent) for some of the small hatcheries (Singholka, 1976). Several of the hatcheries interviewed indicated a 100 percent mortality rate for some of their rearing cycles. This high mortality rate could be caused by human mistake, diseases and/or low water quality. Many hatcheries, especially the small ones, use raw and simply treated natural waters, both fresh and sea water. To solve this problem, technical assistance from the government fisheries stations seems necessary.
The demand for post–larvae is usually low during the dry season (February–May) mainly because of the shortage of freshwater for growout ponds. Many hatcheries have to stop or reduce the scale of their operation during this period if they do not have their own rearing ponds. This situation has resulted in low productivity of hatcheries and inefficiency in resources utilization. Measures to reduce the water shortage problem for rearing ponds during the dry season will increase the demand for post–larvae, which will be discussed in the later section (2.3). It may also be feasible for the government fisheries stations to purchase excess post–larvae from private hatcheries at a reasonable price and to re–sell them domestically or to foreign countries, or even to stock them in natural waters. However, the feasibility of these alternatives should be assessed in the future.
Artemia is the most important item of the operating cost of a hatchery. However, the efficiency of Artemia utilization in Thailand is relatively low. Based on the field survey, one kg of Artemia can feed only 21,000 post–larvae on average in Thailand compared to about 45,000 post–larvae in Hawaii. Improvements in the efficiency of Artemia utilization should reduce the cost of production of post–larvae significantly. To achieve that, technical assistance from the government fisheries stations is also necessary.
The government fisheries stations play an important role in stimulating the expansion of the freshwater prawn industry by providing free or cheaper (than commercial hatcheries) post–larvae and extension service. It is the opinion of the team that only those farmers whose farms are small and who are beginners in prawn farming should have the priority to receive the government subsidy (free or cheaper post–larvae) in order to reduce their cost of production and to give them a chance of success in this new venture. It is recommended that a well defined government policy or criteria should be established regarding the distribution of post–larvae produced by government hatcheries.
Freshwater prawns are cultured in ditches, in natural waters, but mostly in ponds which have spread in at least 40 provinces in Thailand with the largest number being in the Central Plain area. The number of freshwater prawn farms has almost doubled between 1978 and 1980 while the total area increased more than six times (Annex 9). Currently, there are at least 455 farms utilizing about 2,346 rai (375 hectares) of agricultural land and producing about 350 tons of prawn annually with a retail value of approximately ฿70 million ($3.5 million).
The size of individual farms ranges from a minimum of less than one rai (0.16 hectare) to a maximum of 250 rai (40 hectares). Approximately 90 percent (or 408 farms) of the existing farms are less than 10 rai (1.6 hectares), 8 percent (or 35 farms) in the size of 10–40 rai (1.6– 6.4 hectares) and only 2 percent (or 12 farms) over 40 rai (6.4 hectares). Most of the farm owners have other business or grow other crops, such as rice, fruits, other fish species, etc. Except for a few farm owners, who have had more than five years experience in freshwater prawn farming, the majority began operation with the past three years.
The shape of individual ponds varies but mostly they are rectangular with water areas from less than one rai to about 15 rai (2.4 hectares). The ponds are constructed by pushing excavated dirt to the sides to form bunds. Except for a few large farms which have concrete sluice gates, most are simply constructed with pipe inlets and outlets. Water supply is obtained from rivers, water falls, wells, but mostly irrigation canals and is not normally filtered other than by screen. Regular flow-through is not usually practised. Only evaporative losses are replaced with an occasional flushing of the ponds (New, et al., 1980). The depth of water in ponds is about 1.0–1.5 meters. Most of the ponds are protected by fences of nylon netting from natural predators.
In most cases the stocking rate is in the range of 4–7 post–larvae per square meter (m2) but some farms use a much higher stocking density, more than 10/m2. A low stocking density normally results a greater proportion of market size prawns. Based on the field survey, large size farms tend to have a higher stocking rate per unit of pond (Annex 10). Stocking is normally done on a crop basis during the rainy season (June- October).
A variety of feed is used for freshwater prawns in Thailand, including broiler chicken starter pellets, chopped fish, broken rice–rice branfish meal mixtures, etc. Feeding is normally done twice a day at rates depending on demand. Some farms feed daily about 3 percent of the body weight of the stock in the pond while a majority of the farms feed by observation. The amount of feed given per pond can be either increased if the food disappeares within a day or decreased if leftovers are evident.
Harvesting of market sized prawns, 10–15/kg, head on, usually begins 6 months after initial stocking using a 3.81–5.08 cm mesh stretched monofilament net or using a regular round fish cast–net, or even by hand. Prawns below market size are mostly left in the same pond for future harvest. The number harvested per pond depends mainly on demand. Some farms harvest a small amount every day to meet the demand from local restaurants, some harvest every two–three weeks, while some farms harvest all of the prawns at one time after 6–8 months of initial stocking. At the end of a crop, ponds are usually dried and treated with lime before re–stocking.
Annual production per rai varies from less than 100 kg to over 300 kg with an average of about 170 kg (1,063 kg/ha). Prawns are usually sold at the farm gate at a price of ฿130–170 ($6.5–8.5) per kg depending on size. Larger size prawns command a higher price.
Initial investment in pond grow–out averages about ฿16,000–18,000 per rai ($5,000–5,635/ha) depending on pond design and farm size, excluding land cost (Annex 10). A simply constructed pond with pipe inlets and outlets costs much less (about ฿10,000 per rai or $3,125/ha) than a well designed pond with a concrete sluice gate and drainage system (about ฿20,000 per rai or $6,250/ha). For the same type of pond design, the construction cost per rai is relatively lower for larger due to the economies of scale. Land costs very between ฿10,000 and 16,000 per rai ($3,125–5,000/ha).
Annual operating costs average about ฿14,068, ฿10,621 and ฿13,521 per rai ($4,396, $3,319 and $4,225) for small, medium and large farms, respectively. Post–larvae, feed, labor, depreciation and interest are the major cost items, which jointly account for more than 80 percent of the total operating expenses. Post–larvae from government owned hatcheries were originally distributed free. A price of ฿250 ($12.5) per 1,000 is now charged to those farmers deemed to be able to pay. The price of post-larvae from private hatcheries varies from ฿300 to 500 ($15–25) per 1,000 depending on the age of the juveniles and the profit margin. As mentioned earlier, some medium and large farms own their own hatcheries and can produce their own post–larvae much cheaper than market price.
Most of the small farms are run by family labor as a part–time occupation. A salary of ฿1,500 ($75), including meals, per man–month was applied in the calculation. Most of the farms interviewed own their own land and use their own savings. But land lease and interest on initial investment (12%) were included in the calculation as opportunity costs (which means forgone income for prawn production instead of other alternatives). Depreciation costs were calculated based on the economic life of the facilities and equipment. The straight–line depreciation method was used. An earhern pond can last a very long time with proper pond maintenance. Since the cost of pond maintenance was included in the annual operating cost, no depreciation charge was applied to the pond.
Many factors affects the level of production and the cost of production per unit of pond. Experience in freshwater prawn farming, water quality and the management system are the major ones affecting the economics of production. It is the impression from field interviews that most farms with two or more years experience in prawn farming and with good water quality and proper management are doing better than the others.
Again, as with hatcheries, all of the farms interviewed are making a profit. The annual profit per rai averages about ฿8,812, ฿17,379 and ฿10,479 ($2,754, $5,431, and $3,275/ha), for small, medium and large farms respectively. On the average, small farms use more feed and labor, on a per rai basis, than other farms. The average production per rai is in the order of 176 kg, 180 kg, and 150 kg (1,100 kg, 1,125 kg and 938 kg/ha) for small, medium and large farms respectively.
The rate of return on initial investment averages about 51, 108 and 58 percent for small, medium and large farms respectively. These figures indicate that the initial investment can be paid off within the first year of operation for medium size farms and within the second year of operation for small and large ones.
The cost of production per kg of marketable prawn may be used as a rough indicator of farming efficiency. Farms with a relatively low cost of production per unit of output are usually the ones using inputs more efficiently. The cost of production per kg of marketable prawn is the lowest for medium size farms (฿59 or $2.95) followed by small (฿80 or $4.00) and large farms (฿90 or $4.50).
Given the farm price of prawn and the production costs (as listed in Annex 10), the break–even production level per rai - the level of production at a given farm price of prawn that just covers the cost of production without any profit - can be calculated by dividing the annual operating cost by the average farm price of prawn/kg. The break–even production level per rai decreases with the increase in farm price of prawn (Annex 11). For instance, the estimated breakeven production for small farms decreases from 176 kg/rai (1,100 kg/ha) at a given farm price of ฿80/kg ($4/kg) to 70kg/rai (438 kg/ha) at a farm price of ฿200/kg ($10/kg). Also, at a given farm price, the break–even production varies among farm size groups. At the prevailing average farm price of ฿150/kg ($7.5/kg), the estimated break-even production/rai is about 94 kg, 71 kg, and 90 kg (588 kg, 444 kg, and 563 kg/ha) of prawn for small, medium and large farms, respectively. At a given farm price of prawn, farms in respective size groups are making profits when their actual productions are higher than those levels listed in Annex 11. Generally speaking, at the prevailing average farm price of prawn, farms with an annual production of 100 kg or more per rai (625 kg/ha) are profitable.
As mentioned earlier, many farms rely on surface waters and produce only one crop a year because of the shortage of water in the rearing ponds during the dry season. This is reflected in slow growth rates, low productivity of the pond, and inefficiency of resources utilization. In addition, water pollution from industry, households and from chemicals used in agriculture have created problems for many prawn farmers. These problems may be solved or reduced by constructing a well (s) for water supply if feasible. From an economic point of view, it is feasible to construct a well as long as the costs of construcion and operation are less than the benefit derived in the form of increased production and, hence, revenue. The construction cost of a well, together with pumps and pipes, varies manily with its size and depth. It cost one of the largest prawn farms in Thailand about ฿143,000 ($7,150) for a well with a capacity capable of supplying the water requirement for 23 rai (3.68 ha) of rearing pond in 1979, or about ฿6,217 per ($1,943/ha). In another case, one medium size farm paid about ฿80,000 ($4,000) for well construction, together with pumping equipment, with the capacity to provide the water requirement for 17 rai (2.27 ha) in 1979, or about ฿4,706 per rai ($1,471/ha). An average, it costs about ฿5,500 per rai ($1,719/ha) for well construction. A well can last for 15 years or more and, therefore, its annual depreciation is less than ฿400 ($20) per rai. The cost of electricity or fuel for pumping was estimated to be about ฿300 ($15) per month per rai during the dry season. Adding the cost of depreciation for a well and the cost of pumping for 7 months (a crop) amounted to about ฿2,500 per rai ($781/ha). Based on the above calculations, an additional cost of ฿2,500 ($781/ha) for well construction and operation may generate an additional revenue of about ฿22,500 per rai ($7,031/ha) per year (a second crop of 150 kg per rai at ฿150 per kg).
Building small reservoirs may be another measure to solve the water shortage problem during the dry season, if feasible. To study the feasibility of such a project needs detailed technical and economic data and is beyond the scope of this mission.
Many farms interviewed indicated that they do not have enough postlarvae during the rainy season. The inadequacy of seed results in low stocking rates, low productivity of the farm, low revenue and inefficiency of resources utilization. Recently, a few new development programs may help to reduce the shortage of seed. The facilities at the Chacheongsao Fisheries Station are being improved so that the potential production of 20 million post–larvae per year can be achieved within two years. A site for a new government hatchery east of Bangkok is being sought. Another new hatchery with a potential production of 20 million post–larvae per year will be built near Songkhla Lake through the financial of the Asian Development Bank. In addition to these programs, public support in improving the production and distribution efficiencies of private hatcheries seems necessary. This can be done in the form of technical assistance and of the coordination of the production and distribution of post–larvae.
Several farms interviewed also indicated that they need credit but do not know where it is available. Freshwater prawn farming is a relatively new business. Lack of experience in managing this aquatic species, the fact that water quality cannot be fully controlled (especially where surface waters are used), and the problem of insecurity against hazards and predation, all contribute to its high risk factor. Coupled with the high risk, commercial banks are not too familiar with the scientific and technical aspects of this species and lack the expertise to evaluate investment projects in this new field. They have not yet been therefore in offering credit to prawn farmers. However, because many farms are dong well in their prawn business and because the industry is expanding rapidly, some of the banks, such as the Bangkok Bank, the Thai Farmers Bank, the Bank of Agriculture and Agricultural Cooperatives (BAAC), the Krung Thai Bank, Ltd., and the Industrial Finance Corporation of Thailand, have started, or are interested in offering, short and medium term loans to capable prawn farmers up to 70 percent of the total investment at an interest rate of 15–17 percent per annum, except BAAC. Most of these financial institutions offer credit mainly for the purpose of expansion and improvement of existing farms rather than for staring a new farm. Farm owners are required to be resident farmers with at least 2 or 3 years experience in prawn farming and with the ability to repay the loans. These practices leave those subsistence farmers who are interested in prawn farming without financial support from institutional credit sources to start their business. Often they have no alternative but to borrow from non–institutional sources at high cost. Among the banks mentioned above, the Bank of Agriculture and Agricultural Cooperatives (BAAC) was established by the Thai Government in 1966 to provide short, medium and long term credit to individual farmers and to farmers organizations at a much lower interest rate (12%) than commercial banks (see BAAC, 1978 for the terms and the qualification of loans). Credit services are provided to farmers directly through BAAC's 409 field offices. The total loanable funds available from BAAC, however, seems in adequate to meet the farmer's demands. Government support for credit to the small farmers and to the development of the industry as a whole seems necessary and should be considered in the future Aquaculture Development Plan. It is recommended that the Government should set aside sufficient funds in the budget for this purpose. If it is necessary, the Government should approach the World Bank, the Asian Development Bank or other international sources for additional funds.
The efficiency of freshwater prawn production in Thailand is much lower than in Hawaii. On average, the stocking rate and the production level per unit of pond area in Thailand is les than one-third of that in Hawaii (Shang, 1980). Improvements in pond management undoubtedly will increase the productivity of the ponds. Continuous stocking and harvesting rather than stocking once, establishment of nursery ponds in order to reduce the mortality of post–larvae at the early stage of rearing period, polyculture of prawn with herbivorous species, frequent change of water in rearing ponds, and control of predators and pollution are some of the measures required to increase the productivity of a pond. These research programs should be coordinated and carried out by the government fisheries stations, the National Inland Fisheries Institute and the local universities. If necesaary, external assistance should be acquired. The economics of these different management systems should also be assessed in order to determine their economic feasibilities.
In addition to those used in pond production, post–larvae of Macrobrachium rosenbergii have been stocked in natural waters consisting of reservoirs and lakes. From an economic point of view, stocking in natural waters is justified as long as its cost can be covered by the revenue generated. In the evaluation of the economic feasibility of this activity, both direct and indirect (social) costs and benefits should be considered. Direct costs of stocking natural waters include manily the costs of post–larvae, transportation and labor, while the direct benefit would be the total value of the catch from natural waters. Indirect costs and benefits should be assessed under two conditions. First, where there is an excess supply of post–larvae, especially during the dry season, the excess post-larvae may be exported or stocked in natural waters. The indirect costs and benefits in this case would be the difference in the values of production and in job opportunities (hence in income) generated between these two alternatives. The one in a favorable condition generates indirect benefits; otherwise, it may create indirect costs. For instance, if the export of post-larvae earns more income than stocking natural waters, then the difference in earnings between these two alternatives would be the indirect cost (in terms of opportunity cost) of stocking natural waters. However, if stocking natural waters generates more job opportunities in the rural area, then the difference in job opportunities (and hence in income) created between these two alternatives would be the indirect benefit of stocking natural waters. Second, if there is no excess supply of post–larvae (that means post-larvae can be stocked either in commercial prawn ponds or in natural waters), the indirect costs and benefits should be assessed again, according to whether the differences in total values of marketable prawn produced and in job opportunities (an hence income) created are greater or smaller than the other alternatives.
The government fisheries stations have stocked over one million postlarvae of Macrobrachium rosenbergii in natural waters since 1978. The stocking in kwan pa–yao reservoir (10,600 rai) alone was about 250,000 post–larvae by the end of June 1978 and about 200,000 in the middle of April 1979. Post–larvae cost about ฿250 per 1,000 and the cost of transportation was about ฿5,000 per trip. However, little is known about the total catch from this reservoir; therefore the economic feasibility of such an activity cannot be assessed. Without futher information, especially on indirect costs and benefits, one simple way to evaluate this activity is to consider that if all of these post-larvae (450,000) were stocked in commercial ponds, they were enough for stocking 45 rai of prawn ponds and could produce about 6.750 kg of marketable prawn worth about one million Baht. The stocking of this reservoir would be economically feasible only if it earns more net income than stocking commercial ponds. However, if those postlarvae stocked in this reservoir were excess supplies, then the economic feasibility of stocking this reservoir should be evaluated by considering whether the total value of the catch was greater than the cost of stocking and catching.
To conclude, detailed records on catches and the job opportunities created should be kept in order to evaluate the economic feasibility of stocking natural waters in the future.
Freshwater prawn farming is a rapidly expanding industry in Thailand. Thailand is already a leader in terms of total land area used for prawn production. However, the average production per unit of pond area in Thailand is only about one-thrid of that in Hawaii. Fortunately, the low cost of labor, land and other inputs and the prevailing high price of marketable prawn in Thailand have made the industry economically viable based on the results of our field survey. The average rate of return on initital investment is high for both hatchery operation and pond production for all size groops (small, medium and large). On average, the initial investment can be paid off within the second year of operation. This situtation, however, will change when the production exceeds the market demand, resulting in a lower price for prawns.
Based on data collected from field interviews, medium size hatcheries and farms are more efficient, at least at the present time, in producing post-larvae and marketable prawn, respectively, than other size groups. Again, this situation may change when those large hatcheries and farms have gained more experience and improved their management efficiency in the future. Government support to establish a freshwater prawn farmers association, which may help to make small farms more competitive with larger ones, provided it is well organised.
The high profitability of freshwater prawn farming and government support in the improvement and expansion of hatchery operations will further stimulate the expansion of this industry, if a potentially large market, either domestic or export or both, exists for locally produced prawn, which will be discussed in Section 3 of this report. At present, more than 300 potential farmers are on the waiting list of the Chacheongsao Fisheries Station, demanding post–larvae, and many freshwater fish farmers intend to convert to freshwater prawn production. In addition, many exisiting freshwater prawn farmers have plans to expand their operation (Tiandum, personal communication). The government seeks to stimulate an increase in the total potential production of post-larvae of freshwater prawn to 250 million per year within 5 years (New, et al., 1980). At present stocking rates and production levels, this output would be sufficient to stock at least 20,000 rai of prawn pond with an annual production of at least 3,000 tons of prawn and a retail value of about 450 million Baht ($22.5 million). Improvements in pond management could double these figures. However, from the production (not marketing) point of view, this industry will expand only if the suitable production resources, such as land, water, labor and capital, are available at reasonable prices.
Land resources are abundant in Thailand and are not expected to be in short supply for freshwater prawn farming paddy fields and fish ponds for other freshwater species can be easily converted into prawn ponds as long as prawn farming is more profitable. No government restriction exists for such conversions.
Water poses some problems for freshwater prawn farming. Heavy rains during the rainy season creates floods while a shortage of water in the rearing ponds occurs during the dry season. Water pollution also creates problems for many farmers who are relying on surface waters for prawn farming. Construction of small reservoirs, pollution control, and well construction, are some measures for reducing water problems.
Labor resouces are abundant in Thailand. Like many developing countries, unemployment exists, mostly in the rural areas. These under-employed labor forces can be used for prawn farming with minimum training. The lack of qualified extension workers, however, appears to be a constraint for accelerated development.
Capital does not appear to be a significant constraint for the development of the freshwater prawn industry at the present time, but adequate financial support from government agencies, in the form of providing adequate credit to small farm owners, free or cheap post-larvae from government hatcheries, intensified extension and training services, applied research, and other infrastructures, are needed in the future in order to accelerate the development of this relatively young industry.
Finally, it must be said that changes in the prices of inputs and outputs and in culture practices will out-date any economic study. Therefore, the economic evaluation of this industry, (including social aspects), should be up-dated periodically to reflect the true situation. If resources permit, the future up–dating of this economic analvsis should be based on a much larger sample size selected by the stratified (by farm size) random sampling method. The analysis should place emphasis on the major factors, such as farming experience, farm size, levels of major inputs, management systems, etc., affecting the levels and costs of production. In addition, the economic feasibility of different management systems and economic comparisons of the production of freshwater prawn with other selected species and agricultural crops, in terms of returns to land, labor and capital, should be studied. These studies can be carried out by local economists at the Department of Fisheries and the universities. If necessary, foreign expertise should be recruited on a short–term basis to assist in the planning and supervising of such studies.
