Increasing requirements on freshwater use for agricultural, industrial and domestic reasons are gradually limiting aquaculture based on freshwater, especially in tropical arid and rainfed areas. An essential option is the efficient use of marine and brackish water settings for aquaculture. With its euryhaline features and remarkable ability to flourish in saline settings, several tilapia species have been subjected to vigorous brackish and seawater research and culture testing (Lotan, 1960). While salinization of secondary level in many arid and semi-arid regions of the world is a significant environmental problem, affecting up to 380 million hectares of soil, involving 100 million hectares of cultivable land (Ghassemi et al., 1995; Lambers, 2003). Fish farming in brackish water is a scheme of aquaculture that make attention on the manufacture of fin and shell fish of good quality that reside in the, lagoons, creeks and estuaries by rational rearing (Anyanwu et al., 2007). It has ability of connecting wide distance in fish requirement and supply. Fish rearing in artificial or natural water bodies by manipulating environment with the concept of enhanced production more than natural limit is aquaculture. (Jamu and Ayinla, 2003).
There has been a gradual decrease in fish catches and landings in latest decades as a result of pollution, over fishing and the increase in criminal activity in the region of Nigeria (Akinrotimi, 2011). Thus, a viable alternative to fish production is needed to increase the dwindling supply of fish in these coastal areas, and brackish aquaculture fits into this. Brackish water fishing in Nigeria includes the cultivation of fine and shellfish discovered in the coastal environment (Anyanwu et al., 2007). It has the ability to regularly supply the food required, thus contributing to food safety through supplemented feeding and other food-based policies (Klennert, 2009). Brackish water aquaculture plays a key role in the periodic supply and accessibility of fish to improve food security in the coastal regions of Nigeria. The most consumed fish is Tilapia species (Akinrotimi et al., 2015). Tilapia can tolerate, grow and even reproduce in saline waters, although under elevated salinity circumstances this ability is somewhat offset. They are especially susceptible to handling and produce secondary diseases in salinities of seawater. However. It is technically possible to generate seed in salinities less than 18 ppt using clutch-removal management method and to increase the danger in 35 ppt (Suresh and Lin, 1992). By using an adequate climate-friendly production system, trout farming in brackish water is a cost-effective procedure for development of inland aquaculture in Iran (Alizadeh et al., 2016).
In salt affected area, inland saline aquaculture has economic, social and environmental values from groundwater. The problems are tightly connected. At salt affected farms, reduction in crops yield, decreased salary and abridged capital value cause most of farmers to leave their land so affecting the structure and ability of rural areas (Anyanwu et al., 2007). Enhanced cases of stress and depression in rural societies are observed due to economic effects of salinization. Inland saline aquaculture is the economically profitable industry, which is helping the rural societies (Beresford et al., 2001). From an environmental outlook, inland saline aquaculture outcome is usually an adaptive technique for salinity (Braaten and Flaherty, 2002; Starcevich et al., 2003). Salt-affected land is considerably inexpensive than other lands and of additional advantage that it is usually freehold. At the site of successful integration of inland saline aquaculture with salinity capturing arrangements, costs of pumping water can be joined so result in reserves for both enterprises (Doupé et al., 2003). The separation of pathogens and parasites froms inland farms give extra economic advantages by reducing or eradication of disease epidemics and the manufacture of proficient seed stock of disease-free type. Moreover, the incidence or cruelties of some diseases that happen in fresh water can occasionally abridges by enhancing salinity (Altinok and Grizzle, 2001).
In marine or brackish coastal waters, over half of the aquaculture production is taking place worldwide currently (Partridge et al., 2008). Quantity of existing energy for fishes growth can be alter by salinity by changing the ionic and osmotic regulation energetic cost; though, the connection of salinity and growth is multifaceted and not rapidly estimated (Iwama, 1996).
The significant conditions in fish species selection appropriate for commercial-scale, inland saline aquaculture are fundamentally the same for any of aquaculture industry. The nominated species must be healthy, having a fast growing rate, well-established hatchery practices and noble market approval. Rainbow trout seems to be well adjusted to quick variations in salinity and are mostly moved directly from fresh to ocean water in aquaculture grow-out circumstances (Crespi and Lovatelli, 2011). A lot of work is available on the use of GIS and distant recognition in aquaculture (Kapetsky et al., 1988; Aguilar- Manjarrez and Ross, 1995; Aguilar-Manjarrez and Nath, 1998; Arnold et al., 2000; McLeod et al., 2002; Rowe et al., 2002; Salam et al., 2003). Use of GIS, distant recognition and GPS approaches can be used in selection of site of brackish water aquaculture (Gupta, 1995; Ramesh and Rajkumar, 1996).