Recirculatory Aquaculture System (RAS)
Why in news?
India's first commercial-scale tropical RAS-based Rainbow Trout Aquaculture Farm and Research Institute by Smart Green Aquaculture Limited is inaugurated on January 5, 2026, in Hyderabad, Telangana.
About Recirculatory Aquaculture System (RAS)
- RAS is an intensive aquaculture method where fish are reared in tanks (indoor or outdoor) and the water is recycled after filtration.
- Core Principle: Instead of constantly replacing water, RAS uses mechanical and biological filters to remove waste, suspended matter, and metabolites.
- Water Use: Only small amounts of new water are added to compensate for evaporation, splashing, or flushing.
Key Components
- Culture Tanks: Where fish are stocked at high densities.
- Mechanical Filters: Remove solid waste (uneaten feed, feces).
- Biofilters: Convert toxic ammonia into less harmful nitrates via nitrifying bacteria.
- Aeration/Oxygenation Units: Maintain dissolved oxygen levels.
- UV/Ozone Treatment: Disinfect water and control pathogens.
- Pumps & Sensors: Ensure circulation and monitor water quality.
Advantages
- Water Efficiency: Uses up to 90–95% less water than traditional pond systems.
- Space Efficiency: Suitable for urban/backyard setups with limited land.
- Controlled Environment: Better disease management and year-round production.
- High Yield: Supports high stocking densities, making it economically viable.
- Species Flexibility: Can be adapted for freshwater or marine species.
Challenges
- High Initial Cost: Infrastructure and technology investment is significant.
- Energy Intensive: Pumps, aerators, and filters require continuous electricity.
- Technical Expertise: Requires skilled management to maintain water quality.
- Risk of System Failure: Any breakdown can quickly affect fish health.
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