During the later stages of its investigations, the study group reviewed in some detail the conditions affecting the availability of the more important inputs into aquaculture. This Annex contains the (slightly edited) notes of these discussions.
1. LAND FOR FRESHWATER PONDS
1.1 Observations
It is easiest to construct fish ponds in impervious soils. The more fertile the soil is the better for the pond owners. However, ponds can be constructed in poorer soils in which case the lack of fertility is compensated by application of fertilizers; the porus soil is either replaced or lined. Nevertheless, as a rule the better the soil is for agriculture, the better usually is as a medium for pond construction.
Even slightly saline soils can be used for pond construction if they can be supplied with fresh water
Jamaica has some 100 000 acres of land under sugar-cane. This is some 30 000 acres less than in the 1960's. Most of this land has such characteristics that fish ponds can easily be constructed.
1.2 Conclusions
In Jamaica, it is not land as such which prevents an increase in the number of freshwater ponds, but the access to the land and the long-run availability of suitable water.
1.3 Recommendations
In areas where water supplies have been identified as adequate, the Government should let the capacity to pay for the land decide who has access and use of marginal sugar-cane lands (eliminating any distortions that present subsidies might introduce).
Given the overall pressure on agriculture land (exemplified by the large part of the agricultural population which is exploiting the rather meagre hillsides), large extensive fish ponds should be avoided. Ponds larger than five acres should be constructed only when Government approval has been obtained.
2. FRESH WATER
2.1 Observations
Increasing demand for fresh water for all uses is leading to diminishing availability of water for agriculture (and also for aquaculture) in some areas, notably the coastal areas of St. Catherine and Clarendon.
Absence of large freshwater bodies (natural lakes or reservoirs).
There are few perennial rivers; most streams are seasonal in nature.
In coastal areas the water table is high; permissions to drill wells are hard to obtain (from the Underground Water Authority) and, in any case, the risk of obtaining brackish water is considerable.
The waters available in or coming out of the island's morasses seem suitable for aquaculture purposes.
Pumping, either for pond filling or pond drainage, is a common practice amongst aquaculturists.
At present, irrigation authorities do not charge but a fraction of the real cost of irrigation water. It is rumoured amongst knowledgeable persons that water charges will increase considerably in the near future.
Fresh water drained from tilapia or macrobrachium ponds can be used for irrigation purposes.
Fish farmers having ponds in former, or alongside existing irrigated sugarcane lands, normally restitute water to the irrigation system. However, this operation then usually involves pumping, either for filling or for drainage.
There is a total of 16 microdans (January 1983) with a total water surface area of about 35 ha (at main water level). There is little information available on typical seasonal changes in the water level in the dams.
The geology of the coastal areas is such that a considerable part of the runoff from the hilly areas is channelled into underground streams, most of which reappear only just above the shore.
Sections of some rivers, such as Martha Brae, Black River and Great River are likely to have conditions (depth, current and little pollution) suitable for culture of fish in floating cages.
2.2 Conclusions
Although man can perhaps harness rain in Jamaica better than is now the case, in the long run availability of water for use (as opposed to on loan) is likely to decrease. To the extent that the scarcity of water will be allowed to reflect in its monetary price, this means that aquaculture technology which makes little use of water (raceways, cages, pens) will be favoured (economically) over those which make relatively large use of water (pond-based aquaculture).
The absence of large freshwater bodies makes it unrealistic to expect a significant development (in terms of 1 000 t of fish produced per year) in Jamaica, from cage or pen culture in freshwater bodies.
Presently available incentives for fish farmers do not direct them towards a use of water which is efficient for the whole of the agricultural area of which they are a part.
2.3 Recommendations
Do not increase fish pond areas in regions close to present urban/industrial areas or areas expected to have such development within the next two decades. As pond construction is expensive, ponds have an economic lifetime of decades, and once constructed, they have little other use. Therefore, they should not be constructed if there is a likelihood that water will not be available in a couple of years' time.
All fish ponds located in irrigation areas (or areas likely to be so developed) should be provided with physical facilities and equipment ensuring that water let out of ponds will be channelled back to irrigation systems.
Owners of fish ponds for which pumping is required should have an incentive to drain by pumping. In this way, the need for daily pumping is avoided, as is the pumping of water which subsequently is lost to irrigation and seepage.
Fish ponds located in irrigation areas should be made to pay only for the water they use (i.e., the water lost to evaporation and seepage and any water let out of ponds and not let back into the irrigation system), and not for the volume of water let into the ponds (the same principle should hold true for water use in aquaculture raceways).
Water flow should preferably be by gravity, whether for filling or drainage.
Microdams should be stocked with appropriate fish.
3. SHELTERED MARINE WATERS (BAYS AND COVES)
3.1 Observations
With the exception of the Portland Bight, the marine bays along the Jamaica coastline are relatively small. Port Morant with an estimated surface area of about 450 ha is the largest. The bays number 16.
The bays are not equally suitable for mariculture. About four have been identified as suitable for grow-out of oysters (although predators and spat fall has not be considered in this selection process), six for marine cages and seven for fish pens.
Virtually all the bays (the only real exception is Port Morant) are located on the north and western coasts, that is, in the area between Port Antonio and Negril. This is the tourist area par excellence of Jamaica. Therefore, access to these protected bay waters is sought by tourists. Salt March Bay may be an exception.
3.2 Conclusions
The development of mariculture in the smaller sheltered bays will face competition for space from tourists.
The development of mariculture in the Portland Bight region faces the problem of (i) poor access, (ii) pollution in part of the bay, and (iii) likelihood of vandalism and theft.
The development of mariculture in the smaller bays could be promoted during the next few years, given the short lead time for mariculture activities and the relatively modest investments. However, mariculture (in pens or cages) in the long run is unlikely to take precedence over tourist activities, or significantly increase fish production in the bays of the north coast.
3.3 Recommendations
Concentrate the development of mariculture, as far as possible, to the southern coast with emphasis on Port Morant and the Portland Bight area.
Maintain ecological balance in the Portland Bight area and in Port Morant by preventing man-made changes in the extent, or hydrological conditions of the mangrove swamps.
Bay-water pollution originating in agro-industry should be evaluated and minimized.
4. LAND AREAS FOR POND-BASED MARICULTURE
4.1 Observations
There are few typically ideal areas for pond based mariculture in Jamaica. Apart from having impervious soils, the location should have ample water supply to permit the dilution of seawater, necessary to obtain optimum salinity for the growth of penaeid shrimp. There may be 8–10 areas in total.
4.2 Conclusions
The study group believes that the area on the coast just southeast of the mouth of Black River has the best potential as a site for marine shrimp culture. The location could possibly hold some 100 hectares of land that are suitable. The other 8 to 10 areas (mostly marginal agricultural land close to the sea) are each likely to be smaller in extent than the area identified at Black River.
4.3 Recommendations
If government promotes a pilot project for pond-based marine shrimp culture, it should (a) be located in Black River, (b) not exceed more than 10 hectares in area, and (c) have at least some 100 hectares nearby for possible expansion.
5. FISH FEED
5.1 Observations
Virtually all (non-subsistence) tilapia producers rely on pelleted fish feeds to obtain good growth rates. In 1982, about 500 t of fish feeds were used in Jamaica. They were produced mainly by one animal feed manufacturer.
The animal feed industry in Jamaica in 1981 produced about 205 000 t. Thus, fish feeds made up less than 1 percent of the total production of the industry.
The presently manufactured fish feed is based on ingredients, the majority of which are animal feed (or food) industry by-products (an estimated 95 percent in volume and 68 percent in value for the typical feed).
If the study group's projections for aquaculture production in 1986 and 1991 turn out to be accurate, 3 100 t and 9 100 t would be needed respectively in those two years.
Tilapia feeds do not necessarily need animal protein as ingredients. However, the fish feed presently produced in Jamaica has a protein content of 28–30 percent, of which about 50 percent are of animal origin. The use of tilapia feed with proteins of animal origin has been observed to lead to shorter growing cycles (which is equivalent to faster growth rates).
A few fish farmers currently provide feed to tilapia in such quantities that part of the feed becomes fertilizer.
5.2 Conclusions
Although a large part of fish feed components originate in imported materials, it is incorrect to consider fish feed to cause a foreign exchange drain (the by-products, if not used, would have been valueless and their non-use would not have reduced the original foreign exchange costs).
Fish feed is at present a very minor business for Jamaican animal feed manufacturers. It is likely to remain that way (the projected production for 1991 would have occupied about 5 percent of the 1981 output).
The fact that by-products of foreign origin account for more than half the cost of fish feed means that it is unlikely that costs of fish feed will undergo drastic changes, while the demand for the originally imported feed, or food, product is maintained.
5.3 Recommendations
As feed costs are important for most aquaculture production, a policy of full-cost payment by aquaculturists will help to ensure that aquaculture farms are economically sound from the national point of view.
It is recommended that the Government urgently investigate the possibilities and economic viability of using the following substances as fish feed ingredients: brewery waste, brewery yeast, slaughterhouse offal (blood, bones, discarded animal carcasses).
Trials should be carried out to determine the optimum (economic) combination of feed and fertilizers in tilapia pond cultures.
6. FERTILIZER
6.1 Observations
The practice on large fish farms is to use mainly chemical fertilizers.
Ingredients for chemical fertilizers are imported. The part of total imports that is used in fish culture is, naturally, minuscule.
Fish farmers who have access to free manures frequently use them as fertilizers. However, generally chicken farmers find few outlets for their chicken manure as few fish farmers buy manures.
6.2 Conclusions
Availability of fertilizers will not slow down expansion of aquaculture in Jamaica.
There is nothing in the present aquaculture development policy that encourages the fish farm to save foreign exchange by using organic fertilizers.
6.3 Recommendations
The Government should study ways of encouraging the use of organic fertilizer, in particular chicken manure, as a replacement for chemical fertilizers.
7. POST LARVAE OF M. ROSENBERGII
7.1 Observations
A local hatchery (Aqua-Farms Ltd.) is producing post larvae of M. rosenbergii and its management is advertising their availability. The hatchery has installations which would allow it to produce 3–4 million post larvae per year.
The nature of hatchery operations are such that high utilization of capacity is essential in order to keep unit costs low.
Jamaican aquaculturists are not familiar with hatchery technology and management of M. rosenbergii and therefore the IFU cannot effectively advise entrepreneurs interested in establishing such hatcheries.
7.2 Conclusions
The post larvae required for grow-out trials can be obtained through contract with the functioning hatchery.
The lack of local staff with know-how in hatchery technology severely limits the possibilities to produce post larvae outside the existing hatchery.
7.3 Recommendations
The Government should arrange for the training of at least two practising aquaculturists in the practical and theoretical aspects of M. rosenbergii juvenile production (e.g. through on-the-job training in Thailand and/or Hawaii).
Given the availability of commercially produced juveniles, there is no need for the Government to construct immediately its own hatchery in order to be able to conduct grow-out trials.
8. FINGERLINGS FOR TILAPIA CULTURE
8.1 Observations
In early 1983, IFU sold fingerlings to aquaculturists at the price of J$ 0.12 each, delivered at the pond site. This price does not cover all the cost of producing a male, 25–30 g, Tilapia nilotica. The study group has calculated the costs for a 1 million fingerlings per year commercial hatchery at J$ 0.18–0.20 for each male.
The private sector is increasingly producing its own fingerlings starting from mixed sex fry provided by IFU. In 1982 the private sector is believed by the IFU to have produced 0.5 million male fingerlings. In the same year the total supply of male T. nilotica fingerlings was about 1.4 million. The projections for 1986 would point to a need of about 10 million.
Sex reversal, through the use of hormones, appears as a possible way to significantly reduce the manpower input into the production process. However, to date the experiments conducted by IFU have not led to a commercially satisfactory system.
Hybridization for production of predominantly male (at least 95 percent) fingerlings has not been tried in Jamaica. The system is technically feasible. However, the practical difficulty of keeping parent stocks pure has meant that it has not been adopted elsewhere as a commercial system to produce male fingerlings on a large scale.
The Government presently uses a large share of its IFU resources to produce fingerlings. It does not plan to expand its fingerling production facilities in the near future.
8.2 Conclusions
As long as the IFU sells fingerlings at a price remaining significantly below the real cost of production, private entrepreneurs will be discouraged from establishing commercial fingerling production units.
Present Government fingerling production facilities cannot produce the number of fingerlings required by 1986.
If sex-reversal by use of hormones is successful, it is expected that the real cost of male fingerlings can be reduced by up to one-third, which in turn might lead to a 10 percent reduction in production costs at the farm level.
8.3 Recommendations
It is recommended that the unit price of male Tilapia nilotica fingerlings be gradually increased to their real cost, i.e., about J$ 0.18 each in 1983.
The Government should facilitate the establishment of commercial fingerling production units.
Given the possibility to reduce the cost of male tilapia fingerlings through sex-reversal techniques, the Government should intensify research efforts aimed at developing a commercially satisfactory technique.
