Recirculating Aquaculture System RAS Technology Global Development Advantages and Challenges

What is RAS?  

Recirculating Aquaculture System (RAS) is an advanced aquaculture technology. It recycles water and uses mechanical/biological filtration, disinfection, and oxygenation to create a stable environment for fish growth.  

Core Features  

• 1. Recovers up to 99.7% of water, cutting freshwater use drastically.  

• 2. Enables high-density farming through precise water quality control (boosts yields).  

• 3. Reduces wastewater discharge, lowering pollution to oceans and rivers.  

• 4. Operates year-round, unaffected by seasons or climate.  

Key Technical Modules  

RAS relies on these systems to function:  

• 1. Mechanical filtration: Removes solid waste.  

• 2. Biological filtration: Treats ammonia and nitrites.  

• 3. Disinfection: Uses UV or ozone to kill pathogens.  

• 4. Degassing: Removes excess CO₂ and supersaturated gases.  

• 5. Heating/cooling: Maintains stable water temperature.  

• 6. Oxygenation: Ensures adequate oxygen supply.  

Global RAS Development  

• 1. ~350 commercial RAS projects worldwide (excluding hatcheries), focused in Europe (notably Norway), North America, Asia, and South America.  

• 2. Scales vary: from small modular systems (e.g., AquaFounders Capital’s “Farm in a Box”) to large facilities (e.g., Japan’s Proximar Seafood AS, producing 5,300 tons annually).  

• 3. Shrimp RAS: Currently achieves 50 tons per system; plans to expand to 1,000–2,000 tons.  

• 4. Norway (2022): 16% of total salmon fry output (67.5 million fry over 250g) came from RAS—showing its role in seedling production.  

Advantages & Challenges

Advantages 

• 1. Efficient and sustainable.  

• 2. Delivers stable, consistent yields.  

Challenges

• 1. High energy use (for water treatment and temperature control, especially in harsh climates).  

• 2. High upfront construction costs.  

• 3. Requires advanced technical expertise to operate.  

• 4. Sludge/waste treatment is costly—mismanagement can lead to project failure.