The conclusion presented in Section 4 of this report was that the fanning of prawns in Sindh is economically feasible but that the major constraints to its development were the lack of hatchery seed and the need to disseminate the necessary technology to the private sector. The establishment of a small government hatchery, together with facilities to rear postlarval prawns to a suitable stocking size, and the ability to demonstrate grow-out technology, is critical to the development of commercial prawn culture. Site selection for this unit, probably split between a hatchery and a nursery and grow-out site, has been suggested in Section 5 above. The current section of the report lays out the scale of these facilities, the technology and design to be employed, and the costs of establishment, together with some suggestions regarding project implementation.
As noted earlier in the report, the consultant had originally intended to suggest facilities which were half the size of those costed in Section 6.3 below. The current scale of the project was set by the GOS. It is important that the government facilities should not be larger than those proposed below. These are adequate for demonstrating nursery and grow-out technology, for providing a small income for the unit, and for producing postlarvae and juveniles for supply to the private sector to stimulate the development of prawn farming. It is equally important that the hatchery should not be too large, partly because it should demonstrate small-scale, not large-scale, hatchery technology and partly because it should not be seen as a potential competitor to the private hatcheries which it is intended to stimulate.
The facilities have therefore been designed to produce sufficient postlarval prawns to stock nursery ponds for the production of enough juveniles to supply the requirements of private farmers wishing to stock up to 10 ha of ponds at 5 juveniles per m2. The hatchery will also produce enough stock to service the concomitant government nursery and grow-out demonstration and training activities. The demonstration ponds (2 ha) should also produce up to 3 t of marketable prawns annually. The assumption is that recommendations on siting will be accepted, namely that the hatchery will be at, or adjacent to, the MFD Hawkes Bay site and that the nursery and grow-out facilities will be established within the GOS Chilya site. Private farmers receiving instruction in nursery and grow-out technology and being supplied with juvenile prawns for stocking would therefore only need to visit Chilya, following the tradition in existing carp seed supply. Only those farmers who (hopefully) will wish to establish their own hatcheries might need to visit the Hawkes Bay site.
The consultant's Terms of Reference called for recommendations on “appropriate technology packages and preliminary design for freshwater prawn hatcheries, both pilot and commercial”. The technology and design included in this section refers only to a pilot hatchery (and to grow-out demonstration facilities). A technology and design package for commercial hatcheries has not been provided because it is inappropriate at this stage. First, the establishment of a large commercial hatchery is not advisable; so-called “back-yard” hatcheries are more appropriate and have generally proved to be more sustainable for prawn farming elsewhere. Second, the design of private “back-yard” hatcheries will evolve from the successful operation of the government hatchery. No two private (or government) hatcheries are alike; every hatchery manager has different ideas on what constitutes optimum design and technology. The technological and design details and the preliminary cost estimates provided in this report are descriptive in nature. Should a project subsequently be approved, the local survey department can utilize the information provided here to prepare detailed drawings and construction budgets.
In designing the government facilities, it has been envisaged that private farmers would be supplied with 3 g juveniles to stock their grow-out ponds. Later, some farmers may prefer to receive postlarval prawns, which would be less costly, and to operate their own nursery ponds. The facilities and technology discussed here could easily be adapted for this purpose.
In general, the technology utilized by the government unit should follow that laid out in detail by New and Singholka (1984), with a number of specific choices from the various alternatives presented in that manual and some modifications which reflect current practices in prawn farming elsewhere.
Thus, because of the climatic conditions in Sindh, continuous culture in grow-out ponds is not suggested. Grow-out technology should be based on modified batch culture; prawns should be harvested by culling, to remove the faster-growing animals, with a final drain harvest at the end of the season, thus maximizing the production of market sized animals. It has been assumed that the average market size will be a modest 40 g. When grow-out ponds are stocked with juveniles at 5/m2, a production of 1 500 kg/ha/year should be achievable.
Nursery ponds should be stocked with pl-15 postlarvae at 50/m2 and 3 g juveniles should be available within two months.
The initial supply of broodstock (females) required for the first year of operations in the hatchery must be obtained abroad, probably from Thailand. The numbers will be quite small, about 50–60 in total. Prawn brooders can be obtained at the normal price for marketable prawns (unlike marine shrimp broodstock) so the main cost is transport. The import of broodstock requires detailed and careful planning, to ensure that mortalities do not occur during transfer. After the first year of operations, a ready supply of berried females should be obtainable from the grow-out ponds of the government unit at first, and later from those of private farms.
The government hatchery should operate on a “clearwater” system (i.e., without the use of phytoplankton, the so-called “greenwater” system). The “clearwater” system is the one most in commercial use globally (New, 1995); the “greenwater” system complicates hatchery management and has not been shown to confer any advantages (Cook and De-Baissac, 1994). A two-phase rearing system should be employed, to conserve space, equipment and water and feed consumption. This is quite different to the system laid out in the manual of New and Singholka (1984). Newly hatched larvae should be stocked at 250/l into phase-I tanks and reared for 10 days, before transfer to phase-n tanks stocked at 50/l. [Note: higher larval stocking rates are applied in Brazil for example, but are not suggested in the initial stages of development.] Metamorphosis of most of the larvae into postlarvae should be achieved within 25 days of phase-II stocking, at which time the batch should be harvested. Newly metamorphosed postlarvae should be held for a further 15 days in postlarval tanks stocked at 5/l, before transport for stocking into nursery ponds.
The government facilities necessary to achieve these objectives, using these methods of rearing, are detailed in Appendix 6. In particular, that appendix specifies the numbers and sizes of tanks and ponds required.
Combining the unit costs for construction, equipment and operation provided in Appendix 4 with the assumptions of scale given in Appendix 6, cost estimates for the government facilities have been derived. These costs are provided in detail in Appendix 7.
Assuming that existing government sites are utilized, as recommended, no land costs have been inserted in the estimates presented in Appendix 7. Sufficient land exists within the current MFD and GOS sites at Hawkes Bay and Chilya respectively.
Total construction costs at the two sites are estimated to be PRs 4 152 000 ($US 121 226), while equipment costs are estimated at PRs 5 104 000 ($US 149 022). The total capital cost should therefore be less than PRs 10 million ($US 292 000).
Recurring costs are estimated to total PRs 1 674 000/year ($US 48 876/year), nearly 40% of which are staff costs. Apart from staff costs, the largest recurring costs would be feed and fertilizers (28%).
Assuming that the juveniles which are produced are sold at PRs 1.0 each, and that PRs 135/kg is obtained for the market-sized animals harvested from the demonstration grow-out ponds, the facilities would generate an income of PRs 905 000/year ($US 26 423/year). However, it would be unwise to rely on this income, since experimental work may reduce the production of marketable animals and it may be decided that, to stimulate the development of the private sector (as recommended), juveniles should be given away to new farmers for their first stocking, rather than sold. Thus, it would be prudent to estimate that the government prawn hatchery, complete with nursery and grow-out demonstration and training facilities, will cost up to PRs 1 700 000/year (about $US 50 000/year) to operate, excluding capital costs.
During briefing, and during most of the mission, it was assumed that, if prawn fanning in Sindh appeared to be feasible and that the establishment of government facilities would be advisable, the ensuing project would be operated by the GOS. Indeed, this was still the assumption during debriefing with GOS staff. However, during debriefing with the Secretary of the Ministry of Agriculture, Food and Livestock (GOP), the possibility of it becoming a Federal project emerged. As a result, a request for an application for Federal funding for a project to establish a freshwater prawn hatchery and grow-out demonstration farm in Sindh has been initiated. The application procedure may take up to one year to complete.
The establishment of a Federal project would offer several advantages, which should ensure the ultimate success of prawn farming in Pakistan, including the following:
- the recommendation on facility siting, namely to have the hatchery at Hawkes Bay and the nursery and grow-out ponds at Chilya, would become possible;
- synergy between the staff and operations of the upcoming MFD marine shrimp and finfish hatchery and the prawn hatchery would undoubtedly benefit the project;
- cooperation between GOP and GOS staff would be engendered;
- smooth implementation would be more likely, since GOP funding seems more readily available than GOS funding;
- the project would be able to access the knowledge and experience in freshwater prawn farming which already exists within PARC, which is already a GOP establishment. This will ensure cooperation between future research work on this topic at PARC (which is essential) and the development work in Sindh;
- benefits by other Provinces of Pakistan, notably Punjab, would more easily accrue from a Federal project. Once the technology has been demonstrated and initial supplies of seed become available, it is believed that there would be private sector interest in prawn farming in Punjab, as well as Sindh.
An application for Federal funding for the establishment of a hatchery in Sindh has already been tabled by PARC (PARC, 1995). In this, it was envisaged that the hatchery might be sited at the University of Karachi. It is recommended that the GOP consider these two projects together, with the possible objective of combining them or, at least, ensuring that their activities are complementary. Continuing research as well as developmental activities, are essential to ensure that prawn farming is sustainable in Pakistan. The PARC research programme should include not only the general objective of developing technology but also aim to anticipate the needs of the future private sector culture of Macrobrachium rosenbergii relating to water quality, health management, and feed requirements. In addition, it should continue to explore the value of culturing the indigenous species, Macrobrachium malcolmsonii.
While it appears that the granting of government funding for the implementation of this project is likely, some further external assistance would also be beneficial. Training for project staff (whether newly recruited or transferred from other aquaculture activities) would be essential for the successful implementation of the project but should not be provided by sending staff abroad. Far greater benefits would accrue if on-site training were provided by individuals with detailed practical experience, particularly of modern hatchery technology, recruited from other countries where prawn farming is already established, such as Thailand or Brazil. Such trainers should be on-site during at least one, preferably two complete larval rearing cycles. It is therefore recommended that external development assistance should be sought to provide the services of a practical prawn hatchery technologist, for a continuous period of not less than three months. Assistance in this respect might be sought from the Network of Aquaculture Centres in Asia (NACA); similar assistance is already being provided by NACA to the MFD marine shrimp and finfish hatchery project.
The establishment of prawn farming in the private sector will require considerable government stimulation, not only through the provision of the hatchery and demonstration facilities proposed in this report but also through extension services. It may be wise for government to consider providing prawn juveniles free, at least for the first grow-out cycle, to new farmers, a practice which has been found effective in other countries where prawn farming is now a significant industry. Some 45 extension staff, all of Assistant Director level, exist in Sindh. There are three each in Thatta and Badin. Experience in Thailand has shown that adequate extension is critically important for the successful introduction of prawn farming. New farmers, unused to the behaviour of prawns, are often alarmed that they do not observe any prawns at first, after stocking. They then cease feeding, thinking that all the animals have died, or escaped. Later, when prawns are observed again, feeding is re-commenced. However, by this time, considerable growth potential has been lost. This is a common management phenomenon during the first cycle. It is cited here because it illustrates the fact that close cooperation between extension agents and farmers is essential before, during and after stocking as well as during harvesting.
It was not within the consultant's remit to delve deeply into the quality of the fisheries and aquaculture extension services currently provided. However, some concern was raised by the following quotation from the Eighth Five-Year Plan (GOP, 1995): ”(a) major deficiency in extension is because of a poor career structure for the field staff which results in low morale and lack of motivation“. Solving this problem, which is clearly already recognized by the government, will be as essential for the success of prawn farming as for other agricultural and fisheries developments.
