2. Recirculation aquaculture systems (RAS) for land based fish farming
Annual Conference for Trout Breeders
Gdynia, October 11, 2018
Recirculation aquaculture systems (RAS) for land based fish farming
Dr. Astrid Buran Holan, Senior Advisor, AquaOptima AS
Trondheim, Norway

3. AquaOptima AS Localised in Trondheim, Central station
Supplier of RAS since 1993 (spin-off of SINTEF)
Recently became a part of Steinsvik Group
Sister company with Aqualine (cage supplier) and
Steinsvik (water treatment, feeding systems, monitoring/
control systems, cameras, equipment for sea cages)
Agents/cooperating partners in Iran, Indonesia, Bangladesh,
Russia and Iceland
Atlantic Salmon
Tiger puffer fish
Sturgeon
Turbot
Pollock
Grouper
Halibut
Arctic Char
Pike Perch
Koi
Atlantic Cod
Rainbow trout
Whitefish
Seabass
Cobia
Seabream
Tilapia
Japanese flounder
Barramundi
Eel

4. Traditional flow through (FT) Recirculating Aquaculture System (RAS)
Fish tank
Large inlet of new water
Large outlet of waste water
Traditional flow through (FT)
Small inlet of new water
Small outlet of waste water
Recirculating Aquaculture System (RAS)
Treatment

5. Triggers for RAS Not enough water for expanded production
Advantage of steady and optimal temperature for growth throughout the year
Reduced total production time
Better utilization of the concessions in sea
Zero discharge possible
Waste can be used as fertilizer in agriculture
Cultivation of algae for production of biofuel or other products of industrial value
Ikke skalert til oppgaven, uhensiktsmessig utformet. Selv ikke verdens beste RAS kan håndtere mer fôrbelastning enn det er dimensjonert for
Minimal water discharge and collection of waste for further utilisation
Controlling the rearing environment and increasing the production
Independent of the surrounding environment

6. Water treatment steps in RAS -to create constant environment
Bacteria
Bioreactor
Stripper
Oxygen addition
Particle trap
Protein skimmer w ozone
Mechanical filter

7. Water quality requirements
Parameter Safe levels (salmonids)
TSS < 15 mg/L
TAN (NH4+-N plus NH3-N) < 2 mg/L
NH3 – N < – mg/L
NO2- - N < 0.1 mg/L
NO3- - N < 100 mg/L
Dissolved O % saturation
CO < 15 mg/L
pH – 7.5
Density < 80 kg/m3
Temperature °C for Atlantic salmon, °C for rainbow trout**
Ref: Timmons and Ebeling (2007), Thorarensen & Farrell (2011), *Terjesen et al. (2012), **Pers.com. DTU

8. Intake water control Waste Pathogenic microorganisms
Particles and organic material
Humus
Waste
Further utilisation
Sludge dewatering/concentration
Wastewater disinfection