Examination arrangement

Course content

Virtually all new land-based aquaculture systems built in Norway are recirculating aquaculture systems (RAS), and in addition, many of the old flow through systems are being converted to RAS. Recirculation significantly reduces water demand, increases control over water quality, provides opportunities for rapid growth at stable temperatures all year round, makes it easier to handle and utilize waste, facilitates a good bacterial environment, and provides a basis for a more controlled and predictable production both in freshwater and seawater. The course will give a broad introduction to recirculating systems for aquaculture and how the correct water treatment contributes to creating a stable and optimal water environment in the system. Design, dimensioning, start-up, operation, digitalization, and automation will be covered. The course will maintain an interdisciplinary profile where technological function and the importance of biological, chemical, and physical factors are put in context. The course will provide insight into how the requirements for technology and treatment methods change depending on the species and life-stage. The course has a laboratory part where students will gain practical experience through starting and operating model RAS.

Learning outcome

The student should be able to list the most important parameters for water quality, interpret limit values for the most important water quality parameters and assess if the water quality is acceptable for the productino organism. The student should be able to list the different forms of physical, chemical and biological water treatment that are necessary in a recirculation plant. The student should be able to design a simple RAS, with proper dimensioning of biofilter and CO2 removal with regard to a given feeding regime, and state the reason for the how the order for water treatment components is chosen.

The student should be able to provide an overview of available technological solutions and the principle for how the water treatment components work, critical factors for functionality and how the water treatment components affect each other. More specifically, the student should be able to explains the function and effect of a drum filter, a protein skimmer, a hydrocyclone, a membrane filter, a fixed bed biofilter, a moving bed biofilter, UV desinfection, desinfection with an oxidative agent and a CO2 aerator. The student should be able to explain how change of pH affect alkalinity and toxicity of CO2, ammonia and H2S, as well as effectivity of the biofilter and CO2 aerator.

The student should be able to provide an overview of the most important factors during startup and operation of RAS. The student should be able to assess where to start troubleshooting when encountering specific problems durin operatino of a RAS. The student should be able to discuss and suggest measures and action plans when water tratment components fail, when fish show symptoms of disease or when one or more of the most important water quality parameters are outside limit values ofr the organism.

The student should be able to list different types of sensors and methods to measure the most important water quality parameters. The student should be able to use correct measuring methods and measuring information to assess the need for and the effect of different types of water treatment and measures in RAS. The student should be able to give a reason for where to to perform measuring in the plant and to make a plan for measuring of water quality and maintenance of sensors in a RAS.

The student should be able to provide an overview for how physiochemical and biological factors can threaten the health of the farmed organism in RAS. The student should be able to explain the contribution of the ammonium oxidising and nitrite oxidising bacteria in the biofilter and how they compete with the heterotrophic bacteria. The student shoudl also explain how the most important water quality parameters affect these bacterial groups and the efficiency of the biofilter.

The student should be able to estimate amount and form (dissolved in water, as gas or as a particle) of the most important waste products from a given amount of feed in RAS, and to suggest management or use of the waste streams. The student should be able to discuss different alternative for disposal and use of waster from RAS in an economical, practical and environmental perspective. The student should be able to use RAS terminology and communicate well with the industry designing, building and operating RAS.

In the laboratory part of the course the students will do a startup and measure the water quality of a model systen. They will document that the water quality is acceptable before fish may be added. The will set up a simple regulation of a process in the system (i.e. buffer dosing or pump frequency regulated by pH measurement). A laboratory report will be produced by students in groups.

The course will be taught in Norwegian.

Learning methods and activities

The course consists of lectures (40 hours), laboratory assignment (50 hours), excursion (10 hours), and self-study (100 hours). Total workload is estimated to 200 hours.

Compulsory assignments

• Laboratory and laboratory report

Specific conditions