Gulf of Gabes - Environment

The Gulf of Gabes is characterized by an arid to semi-arid climate with low rainfall and a moderate annual average temperature with daily peaks ranging from 41 to 48° in summer. The strongest winds (up to 25 knots) are from W to NW sectors.

The Gulf of Gabes has a very low slope and relief is quite absent which results in a very extended continental shelf (Ben Othman, 1973). The bottom is generally composed of sand, muddy sand and sandy mud (Ben Othman, 1971; Mould et al, 2003), composed of carbonate sediments of biogenic origin (Burollet et al, 1979). The water circulation in the Gulf of Gabes is the result of various hydrodynamic processes such as local coastal currents induced by wind, and tide and currents associated with the general circulation of the Mediterranean waters. The hydrodynamics in the Gulf of Gabes is mainly driven by the Atlantic current. The circulation is characterized by the existence of a local and permanent cyclonic circulation (Lacombe and Tchernia, 1972; Sammari and Gana 1995).

Vertically and during the summer, temperature distribution in the Gulf of Gabes is marked by a strong stratification, leading to two distinct water layers with very different thermohaline properties (Ben Ismail Hammouda et al, 2010).

The gulf is prone to different currents: coastal currents, general currents and tidal currents. Tidal currents are significant and particularly of interest in the Gulf of Gabes. They can reach 30 cm/ s near the coast and about 10 cm /s offshore (Sammari and Gana 1995) which is high compared to other areas of the Mediterranean. The tide is important and semi-diurnal, the maximum amplitude is 2m during spring tides (Serbaji, 2000).