**2.2 Water potential and aquaculture sector in Tunisia**

According to the GDDLHW [21], the Tunisian water network extends over a total area estimated at 20,000 ha, retaining more than 4.2 billion m3 of water. This network consists mainly of dams, hill reservoirs and hill lakes generally located in the north and center of Tunisia. Eventually, the possibilities of development of the aquaculture sector are quite considerable. Indeed, Tunisia has significant natural potentials from north to south, distinguished by the presence of about 30 reservoirs and hill lakes, spread over 13 governorates between the north and center of the country. In addition, the south offers the opportunity to integrate fish farming with agriculture, where groundwater can efficiently contribute to the diversification and production of certain species in geothermal waters including Nile Tilapia. In fact, a great variety of hot water resources exists in southern Tunisia including the geothermal waters whose exploitable quantity is estimated at 737.8 Mm3 /year [13]. This potential consists of deep resources mainly distributed among three aquifers: Intercalary Continental, terminal complex aquifers and Jefarra Basin [15]. This prospect helped initiate endeavors for both tilapia farming and agriculture. Indeed, the idea has converged towards the diversification of breeding species with respect to those introduced in the reservoirs (mullet, pike perch, catfish). Thus, a twofold exploitation and valorization of geothermal water has been achieved as the same water is used for both agriculture and fish farming enriching the agricultural areas with nutrients and fish organic elements [15]. However, the type, accessibility and quantity of the water available, can constitute significant limiting factors for the initiation of tilapia production in the south [16].
