Importance of the conservation and management of freshwater to aquaculture

Inland fish farming contributes to the nutrition and livelihoods of many millions of people. Most fish are grown in constructed ponds or floating cages in natural or man-made water bodies. Freshwater fish farming is often integrated with the farming of crops, where wastes and by-products from one component are used as inputs for another. Developing technologies offer new opportunities to conserve water and increase the productivity of freshwater aquaculture. Recirculating aquaculture systems (RAS) have been developed with the potential to greatly reduce the water requirements and environmental impacts of fish farms. Biofloc technologies (BT) utilize in situ bacterial processes to maintain water quality and provide food for filter-feeding species of fish and crustaceans. Full integration of fish and vegetable production can be achieved through aquaponics, which combines aquaculture and hydroponic plant production within a recycled water system. This chapter reviews current developments in water recirculation techniques, biofloc technology and aquaponics against the background of increasing food security needs and water resource issues.