In accordance with a request from the Government of Israel for assistance in oyster culture at Elat, the Food and Agriculture Organization of the United Nations, under the United Nations Development Programme (Technical Assistance Sector), appointed Dr. P.R. Walne as a consultant. Dr. Walne served in Israel from 6 November 1971 to 29 December 1971. His terms of reference were to formulate and initiate a research programme in oyster culture at Elat (Israel). In particular he was: (a) to assist in surveying sites for oyster culture and the planning of pilot scale experiments, and (b) to provide guidance in the practical aspects of oyster rearing to Government counterpart personnel.
Research into oyster culture at Elat is being undertaken by the government-owned company - the Oceanographic and Limnological Research Co. (OLRC). This company, with the head office in Haifa, is gradually taking over responsibility for most fishery research (freshwater and marine) in Israel.
The terms of reference required that the consultant should survey sites at Elat for oyster culture and to assist in the planning of a research programme. His preliminary studies, however, showed that the more immediate requirement was to investigate the suitability of the area for oyster culture. For this reason the programme of work was extended to include a survey of the potential of Elat for the culture of oysters or other animals with similar biological requirements as well as recommending programmes of research.
FAO is greatly indebted to the many people who collaborated with the consultant during his assignment and who offered their helpful advice and assistance and especially to members of the Oceanographic and Limnological Research Co. - Vice-Admiral Yochay Ben-Nun, (Director-General) and Dr. Abraham Golik (Chief Scientific Adviser). The counterpart personnel, Mr. Hillel Gordin and Mr. W.L. Hughes-Games gave valuable assistance and thanks are also due to Professor Dov Per (Director) and to the staff of the Marine Biological Laboratory of the Hebrew University of Jerusalem who provided working space and other facilities for the consultant.
The Gulf of Aqaba, situated at the north-eastern extremity of the Red Sea, has a length of 150 km and an average width of 16 km. Geologically it is a segment of the African rift system which extends from East Africa to the Dead Sea. The maximum depth of water is 1 829 m from which the sides rise steeply and continue into the surrounding mountains. A sill with a depth of 340 m separates the water of the Gulf from the Red Sea at the Straits of Tiran. The shallow water adjacent to the shore is very restricted. The semi-diurnal tides have a range of 60–80 cm and these are probably considerably affected by weather conditions. The small tides and steep shores make the inter-tidal zone of negligible extent. From time to time a combination of weather and the low water of spring tides causes the top of the fringing coral reef to be exposed.
The whole region is arid; no rivers flow into the Gulf and the surrounding land is mountainous and devoid of plant cover. The average annual rainfall at Elat is about 25 mm but may range between 7.1 mm (1956) and 96.9 mm (1954). Most of the rain comes in short local storms yielding 8–10 mm of rain which can lead to severe flooding. The absence of land drainage leads to a stable but very high salinity of 40–41 percent.
The weather is predominantly sunny, although the average hours of sunshine over a ten-year period at Elat (as registered by a Campbell-Stokes recorder, Table 1) are less than would be expected for the latitude (29°N), because of the shielding effect of mountains to the east and west. Air temperatures are high in August, the hottest month, having a mean of 33.4°C. Detailed water temperatures are not available; the mean values of a number of daily observations taken in the port of Elat are given in Table 1. The bottom water of the Gulf is said to be colder, more saline and more oxygenated than in the Red Sea proper (Morcos, 1970). There is a thermocline at a depth of about 200 m and it has been suggested that there is little or no mixing with the surface water.
A persistent northerly wind is an obvious feature of Elat and this is believed to blow throughout the length of the Gulf. Detailed information on wind strength and direction is available for Elat and a summary for over a ten-year period is presented in Table 2. Southerly storms, associated with depressions in the eastern Mediterranean occur from time to time; easterly winds are very rare. Southerly winds, with speeds exceeding 10 kn lead to a moderate degree of wave action in the vicinity of Elat. The fact that the wind speed exceeds 10 kn from a particular direction for 15 percent of the time combined with the generally exposed shores, bordered by coarse sand or rocks, is an adverse feature of the area for oyster culture. Information on the nutrient content of the water is lacking.
The coastline of Israel at Elat (population 13 000) extends over about 12 km and nearly all is utilized. Starting at the Jordan frontier, the first stretch has been developed as a tourist zone, followed by a military port at the North Quay. The South Quay is used for commercial traffic, an oil terminal and finally, a stretch of coral reef is zoned as a nature reserve. The oil terminal is very active with an average of one or two tankers arriving each day; some are in excess of 200 000 tons. During his stay the consultant saw as many as six tankers anchored within 5 km of Elat awaiting their turn to unload. The anchorage area, marked on the Israel Admiralty Chart, extends all along the north beach up to the Jordan frontier. It approximately follows the 10 m line which is not more than 250 m from the shore. Evidence of pollution, including oil spillage, is not easily seen but clearly this, coupled with the wastes from the adjacent town and port of Aqaba (Jordon) present some risk. The degree of development of the shore line and the necessity for providing sea room for the navigation of large vessels makes it difficult to see how room could be found for the large-scale development of aquaculture.
