Recirculating aquaculture systems (RAS) are used in home aquaria and for fish production where water exchange is limited and the use of biofiltration is required to reduce ammonia toxicity.Other types of filtration and environmental control are often also necessary to maintain clean water and provide a suitable habitat for fish. The main benefit of RAS is the ability to reduce the need for fresh, clean water while still maintaining a healthy environment for fish. To be operated economically commercial RAS must have high fish stocking densities, and many researchers are currently conducting studies to determine if RAS is a viable form of intensive aquaculture.
RAS water treatment processes :
- Solids removal
- pH control
- Temperature control
- Reduced water requirements as compared to raceway or pond aquaculture systems.
- Reduced land needs due to the high stocking density
- Site selection flexibility and independence from a large, clean water source.
- Reduction in wastewater effluent volume.
- Increased biosecurity and ease in treating disease outbreaks.
- Ability to closely monitor and control environmental conditions to maximize production efficiency. Similarly, independence from weather and variable environmental conditions.
- High upfront investment in materials and infrastructure.
- High operating costs mostly due to electricity, and system maintenance.
- A need for highly trained staff to monitor and operate the system.
Recirculating aquaculture is emerging at a good time to meet market demands for seafood and to serve the changing needs of land-based farming operations. The world’s ever-increasing seafood demands are depleting the oceans’ resources.