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History of Recirculation Aquaculture Systems (RAS) in European Aquaculture Focus on Technology and Fish Welfare Your Aquaculture Technology and Service Partner Statement Recirculation technology is not about fish farming, it is about managing the water for the well-being of the fish. Your Aquaculture Technology and Service Partner Your Aquaculture Technology and Service Partner Fish welfare in the EU STANDING COMMITTEE OF THE EUROPEAN CONVENTION FOR THE PROTECTION OF ANIMALS KEPT FOR FARMING PURPOSES (T-AP) RECOMMENDATION CONCERNING FARMED FISH adopted by the Standing Committee on 5 December 2005 (In accordance with Article 9, paragraph 3 of the Convention, entered into force on 5 June 2006) Your Aquaculture Technology and Service Partner Example from the recommendation Your Aquaculture Technology and Service Partner Norwegian salmonid welfare Parameter Level pH level in inlet to fish tanks 6,2 – 7,8 Oxygen level in fish tanks Not more than 100% * Oxygen saturation in outlet of fish tanks Not less than 80% Carbondioxide level - Salmon Less than 15 mg/L Carbondioxide level - Rainbows Less than 10 mg/L Nitrite – fresh water Less than 0,1 mg/L Nitrite - saltwater Less than 0,5 mg/L Total-N Less than 2 mg/L Ammonia Less than 0,002 mg/L *) Super-saturated zones in fish tanks must be avoided when dissolving pure oxygen in tank inlets Norway, Mattilsynet 17.06.2008 Your Aquaculture Technology and Service Partner Your Aquaculture Technology and Service Partner Mechanical Filtration First step in the treatment of water coming from the fish tanks The purpose is to clean the water for faeces from the fish The filter removes particles larger than 40-50 micron (µm) Mechanical filtration is important for the biofilter performance The dirty fraction is washed out of the RAS for external water treatment Your Aquaculture Technology and Service Partner Biofilter The biofilter is most often split into multiple chambers to ensure optimal conditions for different biological processes Fixed bed technology or moving bed technology or a combination between the two types Organic material is consumed by heterotrophic bacteria in the first chambers The following chambers will perform optimally for nitrification (converting ammonia to nitrate) Ammonia (NH4) Nitrite (NO2) Your Aquaculture Technology and Service Partner Nitrate (NO3) Degasser ꞊ CO2-stripper ꞊ trickling filter Effective CO2 removal is crucial for fish welfare, optimal growth and reduced feed conversion rate (FCR) CO2 degasser must be extremely efficient, and can be dimensioned to any CO2 concentration Your Aquaculture Technology and Service Partner UV-disinfection UV treatment is especially recommended when growing small fish – 100% treatment In grow-out systems, the concept of partly UV treatment will stabilise bacterial dynamics The harmless bacteria will be favoured and outcompete pathogenic bacteria that might enter the system (pro-biotic concept) Your Aquaculture Technology and Service Partner Oxygenation Pure oxygen is injected to the process water to enhance the availability of oxygen for the fish Sufficient oxygen levels are needed for the wellbeing of the fish and for optimal feed conversion High oxygen saturation throughout the RAS is crucial for overall system performance Injection is most often done by the use of high pressure oxygen cones Other oxygenation methods are available: Low head oxygenation, venturi injection etc. Your Aquaculture Technology and Service Partner Pumps Only one point of lifting the entire water volume of process water saves energy Custom designed for each project to optimise efficiency and reduce running cost Pumps also necessary for injection of pure oxygen, back-washing of biofilters and pressurised cleaning of the mechanical filter Your Aquaculture Technology and Service Partner RAS cost distribution – portion trout Note: Energy costs are 7% only Your Aquaculture Technology and Service Partner Principle lay-out of a RAS Your Aquaculture Technology and Service Partner Desktop and mobile Client Your Aquaculture Technology and Service Partner 16 Continous logging Your Aquaculture Technology and Service Partner 17 Your Aquaculture Technology and Service Partner System configuration Growout 0.400. System Data Sheet Item Group Item Name Specification System Primary tanks Circular Fish tank, ø9m standard version 10 pc at 170,0 m3 2,06 exchanges/hr Total system volume (excluding reservoir) 2.550 m3 Total system flow 3.500 m3/hr Total tank flow 3.500 m3/hr Total biofilter flow 2.900 m3/hr Total biomedia surface area 510.000 m2 Performance Peak feed capacity (according to specified comp.) Peak water exchange Your Aquaculture Technology and Service Partner 1.802 kg/day 14,7 m3/hr Concluding remarks • • • • • • The technology works Complete control of the production environment Good water quality for both fresh water and saltwater systems Fish are growing well and have good health standards Need for better understanding of conditions for fish welfare More applied research needed Your Aquaculture Technology and Service Partner Thank you for your attention Your Aquaculture Technology and Service Partner