Dept. of Civil & Environmental Eng.,Technion, Israel Inst. Of Technology
Haifa, 32000, Israel
Production of tilapia, for home or local consumption and for export, has been raised tremendously in the last few decades. The tonnage of world wide tilapia production (in 2010, about 3 million tons) is second, among fish, only to carps. Global production of tilapia was estimated to be 2.5 billion US$ in 2010. The present trends indicate a continuous growth of production and expanded penetration of that fish to a variety of markets, from expensive restaurants to local households all around the world.
Higher production levels are needed and anticipated; however, increasing aquaculture production is limited, globally, by the severe limitations of water and availability of suitable land. The only feasible and environmentally acceptable way to raise aquaculture production is by the use of intensive systems. The choice of suitable intensive systems to produce commodity fish is limited due to the need to produce the fish at a cost lower than the market price. One of the systems that enable intensification at a relatively reasonable investment and running costs is biofloc technology.
Biofloc technology is based upon the running of the pond using minimal water exchange, subsequent development of dense microbial population and managing the microbial population through the adjustment of the C/N ratio so that it controls inorganic nitrogen concentration in the water. The bacteria, forming bioflocs, assimilate TAN, produce microbial proteins and enable to recycle the unused feed protein. BFT systems are widely used for shrimp production world wide. (For more details: Yoram Avnimelech, Biofloc Technology, A Practical Handbook, World Aquaculture Soc. 2010). Tilapia is ideally adapted to BFT systems. It is herbivore, essentially a filter-feeder adapted to the harvest of bioflocs suspended in the water, it can grow and flourish in dense systems and is overall a strong and stable fish. Using BFT systems for tilapia production is an obvious choice.