Recirculating Aquaculture Systems (RAS)
Designing Innovative Aquaculture Solutions
Recirculating Aquaculture Systems (RAS) are land-based, closed containment rearing systems with full water treatment and recycling technologies employed, that offer economic and fish husbandry benefits to the farmer. RAS systems have been used for fish farming for over 20 years in hatcheries and grow out systems for a wide variety of species. Increased demands for farmed fish combined with the challenges of access to new open water culture sites for traditional fish farming are now causing this market to explode.
ATI is developing RAS technologies for applications where water access is restricted or where limited water resources are available for land based farm consumption. RAS systems allow water quality of the rearing environment to be controlled, thus accelerating fish growth and crop turnover, while the entry of pathogens is minimized, as only small make up water flows need be treated.
The discharged water carrying nutrient goes through a series of purification and regulation treatments before being partially or totally reused. Water treatment processes include solids removal (waste and uneaten feed), biofiltration, gas balancing, oxygenation, and disinfection. For example, the high water quality is achieved by using drum filters, bio-filters, ultraviolet sterilization for pathogen control, as well as ozone filtration.
- Fish products can command premium pricing
- Improves feed conversion ratios
- Increases bio security
- Optimizes growth rates
- Provides consistent biomass once steady-state is reached
- Controls water temperature and salinity levels
CAD drawing courtesy of JLH Consulting Inc.