At present, aquaculture in Syria is controlled by the GEF which has the biggest farms. The GEF intends to maintain this control and to programme the future development of aquaculture.
Inland aquaculture in Syria is divided into two principal types: coldwater fish culture in concrete basins with trout, and warmwater fish culture in earthen ponds with carp and tilapia.
Trout, although only recently introduced and not yet fully accepted by the market, could have good technical potential in Syria (the advisability of trout farming has been questioned on economic grounds by Lamendour1) considering the cold springs with constant suitable water temperature (14°C) near the Sin area and Zabadani as well as the new site at Rable, near Lebanon. Nevertheless, the present plants suffer constraints of both a technical and administrative nature.
The Nib Al Sin trout farm and to a greater extent Zabadani, are built in a bizarre fashion and their management is difficult.
In the present situation, given that extensive structural changes are not possible and that these plants must produce only the following managerial recommendations can be made to improve fish production:
the quality of the water should be checked and in particular the gases in the Sin and Zabadani springs must be recognized;
a degassing system must be inserted between the elevated tank and the rearing basins or underneath the inlet of the water in the tanks (over-layed screens, Japanese mill, etc.) to eliminate the excess gases and to increase the oxygen content;
the local production of eggs with domestic parents must be increased to substitute the more expensive imported eggs;
the introduction of adults from abroad must be excluded, to avoid the infection of fish-farms with VHS (Viral Haemorrhagic Septicaemia) (not yet observed).
These two species are well accepted on the market, especially in the inland region; their price is good and their body shape is familiar. The traditional pond farms find suitable land and water, especially in the spring area of the Al Ghab valley.
The present farms suffer from some technical problems (incorrect slope of canals, interruption of the water supply, impossibility of drying completely some of the ponds, etc.) but they suffer mainly from the managerial point of view. The following is there-fore recommended:
to investigate the best fertilization schedule in relation to the quality of the water and of the soil;
to respect the programmed order and time of all the following operations:
drying, treating with quicklime, filling with filtered water, fertilizing
and manuring
(It should be remembered that several consecutive fertilizations are
required for an optimum control of the productivity of the pond rather
than one single fertilization.)
to investigate the best combinations of species, density and sizes to obtain the best utilization of the productivity of the pond and the highest yield.
Good new sites for fish-farms are present in Syria both for trout, and carp and tilapia. Sometimes new plants are justified by the general policy of aquaculture, such as trout, rather than an effective demand from the market.
It is recommended that much more longterm information on water quality and quantity and soil quality, be collected, and that particular care be taken in projecting and building the farms.
Particular pathologies have not been found but it has been observed that there is a general situation of sufference in particular for trout, probably connected with the environmental stresses of overcrowding, lack of water supply, small basins, poor quality food. In this situation it is recommended that the overcrowding be checked and where possible the water supply be increased.
It is recommended that a prophylactic treatment be adopted against parasites (Gyrodactylus, Dactylogyrus, Trichodina, Chilodonella) before releasing the fish in the ponds and cages.
The introduction of new species must be the object of careful study. First, it is recommended that the production of the present species be improved and subsequently the role of the species at present secondary in fish culture but just accepted by the market, could be increased: the grass carp Ctenopharyngodon idella; the silver carp Hypophthalmichthys molitrix, the bighead carp Aristichthys nobilis; the African catfish Clarias lazera; the European catfish Silurus glanis, the mullet Mugil sp. and the eel Anguilla anguilla).
Moreover, it is recommended that only male tilapia be grown since they have a much greater growth capacity, and also to control proliferation. This can be done by sexing the juvenile fish (differences in their genital papillae) or by reversing the sex at an early age by feeding hormones. The tilapia stock could be maintained during the winter in floating cages directly put into the warm spring lakes or in warmed and protected basins with closed cycle and heating systems.
The use of warmwater discharged by the power station appears to be uneconomic for this purpose in freshwater, due to the high gradient in water level.
A better control of the water characteristics (T°C, DO, NH3) is recommended, both of the inlet waters and of the water in the rearing basins. In particular, it is recommended to identify the gases of the Zabadani spring and Masab Al Sin fish-farm complex spring and to prepare a stirring system.
In general, aquaculture in Syria suffers from a lack of theoretical and managerial knowledge. This problem may be solved by training both with seminars in fish-farms abroad and with courses in Syria by foreign experts. Studies should be included on the best fertilization schedule for ponds and the best composition of the polyculture to obtain the maximum yield.
Detailed recommendations are listed under each section.
