An aquaculture plan and a policy for its implementation should not be developed until all potential types of culture have been appraised. The appraisal should include economic viability, possible extent of culture and social relevance. As the number of possible culture systems is very large, the mission initially considered them either in groups of culture systems or in relation to a particular species or species group.
The systems considered for marine fish-farming in the Mediterranean are:
extensive systems: lagoon or estuary management
semi-intensive systems: enclosures; valliculture; pondculture
intensive systems: cages; raceways
(a) Extensive systems
There are no lagoons and no large estuarine areas in Syria; such systems are therefore not considered.
(b) Semi-intensive systems
Enclosures: successful establishment of the marine fish in enclosures requires areas well protected against wind and current, and a shallow depth. These conditions do not exist in Syria and this system cannot be considered.
Valliculture: “valli” culture is practised mainly in Italy. The mouth (or mouths) of a suitable lagoon is closed off by screened weirs incorporating fish traps so that tidal flow in and out of the lagoon can be controlled by operating the weirs or sluices. All the flow can be made to pass through the fish traps. The operator therefore, has control of the water and of the entry of aquatic animals of a size that cannot readily pass the screens or traps; the fish which grow in the lagoon are trapped when they try to make for the open sea. For the abovementioned reasons such a system cannot be considered.
Pond-culture: a pond is an area closed by a dike in which fish is reared in a limited density (1–10 t/ha) and feed exclusively or partly on natural productivity of the water which can be increased by fertilization; complementary feed can be distributed, and water change is usually limited to, e.g., once a month or every 3 months.
There are no technical obstacles to the commercial culture of fish in ponds in Syria. Large areas at sea level exist especially in the south near Tartous. The required inputs (apart from an adequate supply of fingerlings) are available but the costs and benefits should be examined and compared (Appendix 7 contains an appraisal of a pond fish-farm).
As far as can be estimated in the light of information at present available in other, Mediterranean countries, economic conditions seem favourable for pondculture of selected species (mullets, sea-breams). In addition, it is noted that Syria has gained a first experience in pond polyculture (carps, mullets and tilapia). One of the largest farms (Sin) is situated near the sea and could change to brackishwater farming, with little additional investment; this is an interesting possibility as, should there be a lack of fresh water in the future, the water-spring supplying the farm could also be diverted for agriculture and urban uses.
(c) Intensive systems
Such systems do not use the natural productivity of water (water is used only for fish sustaining), and feeding is necessary. In addition, oxygen supply and elimination of wastes require a permanent waterflow.
Cages: cages require conditions similar to enclosures, being protected against waves, wind, etc. While this system is well adapted to large freshwater bodies (e.g., Lake Assad), it cannot be considered along the Syrian coast.
Raceways: this system can be implemented everywhere in the Mediterranean; the main problems to be considered are the permanent consumption of energy and necessary use of feed. The advantages are a better control of water quality, easier stock management and a very high production per surface unit. In Syria, cost of energy is low and seems to be economically supported by fish production; feed costs are no higher than in other Mediterranean countries (apart from imported feed), and local ingredients could be used to compensate for imported feedstuffs. Intensive culture of marine fish could be economically profitable.
(see Appendix 6A)
All the marine fish in Syria fetch very high prices (from £S 25 to 70/kg). The selection of species suitable for marine aquaculture should be based mainly on technical criteria (state of knowledge in farming the concerned species, availability of material for stocking, biological characteristics of species), rather than on economic factors.
(a) Mullets (Mugil sp.)
In Syria the price of mullet is fairly high. The fry occurs along the Syrian coast in small river mouths, and is still collected (at a pilot-scale level) to supply a few ponds in freshwater farms. Several species are present, and it is difficult to cull the less desirable species until the fingerling stage. Since suitable sites for ponds exist, monoculture of mullet in seawater or in brackishwater ponds could be economical. Adaptation of experience gained, either in freshwater farms in Syria or in brackishwater in other Mediterranean countries, should be considered, through trials on an experimental or pilot scale. Mullet production could also be experimented in polyculture (see below 3.4).
(b) Sparids (Sparus aurata, Diplodus sp., Pagellus sp.)
Sea-breams fetch high prices both nationally and in neighbouring countries (Lebanon). Production is not sufficient to cover the demand, and imports from Turkey or other countries are very important. Sparids could be produced, either in intensive raceway culture, or in semi-intensive pond production. In the Mediterranean, culture technologies (controlled breeding, feed production) are available for Sparus and Diplodus. Commercial production exists only in semi-intensive systems (valliculture; pond culture). Depending on the limited production of fingerlings by hatcheries, intensive production of sea-breams has not yet been achieved in Syria and is only 2 or 5 t per production unit. Trials should be carried out on these species and at the same time surveys conducted to assess the availability of sparid fry from the wild.
(c) Groupers and Seabass (Dicentrarchus labrax)
One of the favourite fish is the grouper (Epinephelus sp.). They find a ready market, not only in Syria but also in Lebanon, and command a very high price. Similar species are grown commercially in floating cages in Hong Kong and in earthen ponds in Thailand and Malaysia; all these systems rely upon capture of wild fry and it is doubtful that this would be possible in Syria given the scarcity of fry or mature adult groupers caught today.
Seabass is much more common in Mediterranean aquaculture and is already in commercial production, using hatcheries. Optimal temperatures are between 19° and 23°C, but good results are also obtained between 15° and 28°C. Such temperatures prevail in Syria for 10 months of the year instead of the 5–6 months of the northern and western Mediterranean. Seabass was usually present in Syrian coastal waters but overfishing occurred in the 1960s and this species now is very rare; however, fry could be easily obtained from other Mediterranean countries, and as technology is well known, this species is recommended for initiating an aquaculture project.
(d) Amberjack or Yellowtail (Seriola dumerilii)
This species is common enough along the Syrian coast and its market price is high. Similar species are grown in floating cages in Japan; however, this culture also relies upon capture of wild fry, and is successful only if they feed on fresh trashfish or proteinrich feed. This species is not recommended for culture during the next few years.
(e) Tilapia (see Appendix 6B)
Tilapia is a species will suited to freshwater farming because of its tolerance to varying water quality, its easy reproduction, and a good utilization of natural or artificial food. The only constraint for tilapia farming is the temperature; at less than 16°–17°C tilapia does not feed and it dies at temperatures lower than 10°–12°C. Tilapia farming in seawater is now conducted in several countries, with salinity-tolerant species: on-growing is carried out, either in monoculture or in polyculture, e.g., with mullets.
The only crustaceans of interest for aquaculture in Syria are penaeid shrimps. They fetch very high prices, the highest among the fish products. They are caught by traps and sold alive or very fresh. There is much interest in the possibilities of shrimp culture, especially because of the temperature range (above 20°C) suitable for shrimp culture for 8 months of the year. Species to be considered are Penaeus japonicus, P. kerathurus and P. semisulcatus.
The culture of shrimp on an artisanal scale using rather simple techniques is widely practised in southeast Asia. More sophisticated systems are in operation in Japan and Taiwan. Hatchery techniques are well developed. Direct adoption of the simpler techniques in Syria is hindered by the small tidal range which makes pond filling and refreshment impracticable except by pump. More should be known about the geographical distribution and abundance of the various species of shrimps and the seasonal availability of breeders.
In order to appraise the viability of penaeid shrimp culture, two types of culture are considered - in monoculture and in polyculture with fish.
(a) Monoculture of penaeids
There would be only one production cycle a year (two cycles may be possible but insufficient data are available to be sure of this possibility). Post-larvae would be produced in a hatchery in March–April; and, after 30 days in nursery ponds, would be released into the rearing ponds at a rate of 50 000–100 000/ha. The yield could be between 1 and 3 t/ha/year, average weight 30–35 g, at a food conversion ratio of 3.5:1 (dry pellets).
(b) Polyculture with fish
This system is used in southeast Asia with milkfish. It could also be used with mullets, but no commercial enterprise practising such a system is reported to date. The main advantage consists of a better use of the ponds and for a longer period throughout the whole year. Another advantage, especially in Syria, would be to produce a highly-prized product (shrimp) together with a fish of larger consumption (mullet). Technical and economic appraisals should be obtained through trials (see Appendix 9).
There are no molluscs on the market in Syria. However, such a production could find a limited outlet in tourist hotels and restaurants. The main problems (molluscs are organic and plancton feeders) are the poor water quality and the lack of wild mollusc populations along the Syrian coast. The only way to develop such a culture would be to use water effluents from intensive fish-farms, and imported spat. Trials could be carried out, but commercial development will be very limited.
Integrated aquaculture is a system which attains the twofold result of obtaining high production and developing natural productivity. Farms of this type consist of intensive fish-farming sectors (raceways) and semi-intensive ones (ponds). The former produces autonomously from the latter, with external inputs, and by using their effluents as fertilizer for the extensive system.
In addition, the intensive sectors give the semi-intensive ones the “semi-cultivated” fish material in optimal biological and operational condition in relation to environmental productivity, and also transmit to them a sizeable proportion of “recuperated” energy represented by the waterflow and culture catabolites.
The semi-intensive sectors are not limited to “receiving” but play an active role, performing various cultivation operations mainly in relation to water management, oxygenation, preparation of bottom grounds, additional fertilization, etc.
In order to create as favourable an overall energy balance as possible, care should be taken to establish rational proportions between the intensive sectors; adopt the approprivate cultivation operations for the semi-intensive sector; and make the application of supplementary energy commensurate with the results that can be obtained.
All of this should lead to:
attaining as rapid a production rate as possible;
utilization of all the available energy for production purposes;
limiting dispersion of energy to the external ecosystem within well defined levels.
In Syria, such a system could be adapted to intensive culture of seabass and seabreams; and semi-intensive culture of seabream, mullets and tilapias.
Investments are higher (per ton of fish produced) than in intensive systems, but costs of production and especially of inputs (energy, feed) are much lower. Production of 1–1.5 t/ha/year should be obtained in the semi-intensive farming ponds without any supplementary inputs using the effluents from 2–3 t of seabass cultivated in raceways.
Most of the aquaculture systems proposed, with the exception of mullets, require reproduction facilities: intensive fish-farming, shrimp farming, polyculture, integrated aquaculture. Hatcheries have to be built step-by-step to supply the grow-out farms. These facilities are expensive, require skilled manpower, and cannot be implemented immediately on a large scale. Close to the hatchery, fry-rearing raceways are needed to produce fingerlings of 1–5 g. At this size, they can be transferred to grow-out facilities (see Appendix 10). The use of heated water in winter, especially for fingerlings production (or for intensive grow-out operations), could be advantageous and such a possibility exists at the Baniyas power station (see Appendix 14).
Section 3 reviews the economic potential of culture of various marine species, in different culture systems. Because of the physical characteristics of the coastline and the economic characteristics of the market, the five following systems are recommended:
intensive culture of finfish in receways
semi-intensive culture of mullets in ponds
culture of shrimps in ponds
polyculture of fish and shrimps in ponds
integrated systems of intensive luxury fish culture and semi-intensive cheaper fish culture.
It has appeared that the first two systems and the last are technically and economically suitable for Syria. The other two systems, involving shrimps, would require more basic data and experiments would be necessary.
All the other systems which the mission assesses to be of no economic interest during the next few years will not be considered further.
