Centre for Closed-containment Aquaculture (CtrlAQUA)

CtrlAQUA aims to develop technological and biological innovations that will make closed containment systems for post-smolt up to 1 kg a reliable and economically viable technology. Common for closed facilities is that they have a physical barrier between fish and the external environment that prevents lice from meeting fish and fish from escaping. In CtrlAQUA, we have focused on land-based facilities where the water is recycled, so-called RAS. The other main type is floating semi-closed facilities at sea, where water is pumped into the system from water depths below the lice layer. In CtrlAQUA we have done research regarding welfare, preventive fish health and technology development on the fish's premises. To ensure good health and welfare throughout the life cycle, it is important to ensure that the fish are robust. CtrlAUQA have aimed to make the fish robust by defining factors that affect robustness and recommending optimizations. We have worked with gene markers for stress management and fish welfare. We have documented that immune genes are at a low level when the fish are between smolts and post-smolts, and that this gene expression, together with protective mucus layer, are strengthened after months in sea. We have also contributed to the development of a “health test”, that is a diagnostic test that measures the activity of 44 genes that are important for the immune system. Optimal smoltification protocols are important for robustness. With the use of controlled experiments where we followed the fish all the way to market size, we have had the possibility to see the final results of effects of industry relevant protocols where the input variables during two lifecycle experiments have been different durations of and time for introducing photoperiods, salinity and fish size at sea transfer. We already know that salmon have a health benefit from exercising, and we have shown that swimming speed in post-smolts of 1-1.5 BL / sec provides optimal growth and minimal welfare challenges such as poor skin health that can be observed at high water velocities. Partners in CtrlAQUA have asked for research on the effectiveness of disinfecting biofilters and the effect on fish. A published survey showed that peracetic acid is a common disinfectant in Norway and North America. Experiments with fish showed that periodic use of peracetic acid causes stress and mucus production, but that the fish show signs of adaptation. Thus, periodic use of peracetic acid can be recommended. Furthermore, we showed that the start-up time of biofilter after disinfection depends on disinfectants and methods. The most effective are chlorine and pH adjustment. Further research showed that biofilters in brackish water are more resistant to an increase in salinity than biofilters in fresh water. CtrlAQUA has previously mentioned that the use of ozone has advantages in fresh water, as it provides clearer and better water quality, while it may present challenges for the fish in seawater due to toxic bromides. CtrlAQUA research shows that ozone levels in brackish RAS of 330 - 350 mV can provide better gill health over time. Treatment of large amounts of intake water can be done with medium pressure UV. We have investigated how much UV it takes to eliminate 99.9% of several microorganisms with a real threat both in RAS and in SCCS. Much of the research in semi-closed facilities has taken place in time series, in the absence of replicates and good controls. After several generations with registrations in two of the prototypes, we have seen that the performance is very good in SCCS and also after the fish has been transferred to open net. In addition, the increased growth resulted in more biomass over the same period in SCCS compared with open net. With increasingly large and complex systems, good hydrodynamics are crucial for self-cleaning and optimal distribution of water and fish. In CtrlAQUA we have worked with empirical description and modelling for optimal design in RAS and SCCS. We also modelled the movements of different particles and how these affect the tank hydraulic. In the mid-term evaluation, we introduced three new focus areas that we have implemented in the work plans since 2020. These are the formation and analysis of hydrogen sulphide, factors that lead to early sexual maturation, and more knowledge of what causes kidney stones (nephrocalcinosis) and how we can detect and prevent this condition. For the latter, we have compared how early one can detect nephrocalcinosis using histology and X-ray, up against visual assessment, and we optimize the use of X-ray by validating against histology. Optimal water quality in RAS and SCCS have been important and CtrlAQUA made an overview of limit values for RAS with our own and others results. We have also worked with good measurement methods for water quality with the development of sensors and how these can be protected against fouling by using membranes.

CtrlAQUA has contributed to the development of technological and biological innovations to make closed-containment aquaculture systems a reliable and economically viable technology, for use in strategic parts of the Atlantic salmon production cycle, thus contributing to solving the challenges limiting the envisioned growth in aquaculture. From our perspective, we have achieved the goals of the centre. Through 15 innovations representing technology development and securing health and welfare in the systems, we have contributed to the development of RAS and semi-closed systems. There are still developmental needs to complete the systems to become “off-the-shelf” ready, especially for the semi-closed systems. Many of the challenges are on the regulatory side as the regulations prevent the systems to perform as intended. Also, there is need for further closing the systems with the development of treatment of inlet water and discharge to prevent pathogens and pollution. This will make the systems even more expensive, so to enable the full potential to prevent lice and escapees of these promising solutions, and thus to serve as sustainable solutions to the planned growth, appropriate regulations and conditions are required. The global impact of CtrlAQUA have been described by one of the industry partners: “RAS technology have become a more "of the shelf technology" in the SFI life span. RAS is now proven to work for smolt production, even though the cost issues for investment needed in systems and an energy cost remains to be improved. In the beginning of the SFI period, RAS technology had a lot more questions and uncertainties. Most of these issues have been addressed in the centre or in associated projects, leaving us in a much better position today when it comes to understanding and the use of the technology. On the other hand, the S-CCS technology for post-smolt have gone through much of the same journey, leaving us with a better insight now of what remains to be solved. The different speed of development for RAS and S-CCS reflects the regulatory regime that have been applied in Norway in the centre lifetime and is not only limited by the SFI's efforts to bring S-CCS up to the same insights as RAS”. CtrlAQUA has achieved the goals through 21 dedicated R&D and industry partners, 16 PhD and close to 60 MSc students. This has led to close to 100 peer-review publications and 42 factsheets. The knowledge transfer has also been done through internal and external meetings. Most students have graduated and are well situated in relevant positions in the industry or academia. The international collaboration including partners from USA and Sweden, and an international scientific advisory board has also contributed to the international impact. An important outcome for the partners is the long-lasting networking activities between partners and have resulted in partner visits for project work, but also for developing new ideas that has resulted in new projects.

The Norwegian Government and Atlantic salmon industry have a vision to increase the aquaculture production volume five-fold within 2050. However, there are increasing concerns related to the challenges in salmon aquaculture, with sea lice, infectious diseases, escapees, and the loss of 16% of all fish transferred to open sea-cages. To reach the envisioned goal of growth, a strong research-driven innovation effort is required to ensure minimal environmental impact and fish mortality, challenges that are limiting large-scale increases in production. The CtrlAQUA Centre will contribute solutions by innovating tomorrow's technology and knowledge necessary for using closed-containment systems (CCS), during strategic parts of the salmon production cycle. Our main innovation will be reliable, controllable and efficient production of post-smolts in CCS on land and at sea, thereby providing a realistic option for the aquaculture industry. The Centre will provide the industry with several technological or biological supportive innovations and educate 15 PhDs. CtrlAQUA will be a light-house for the industry and research community by providing solutions for production of healthy seafood with a low carbon footprint. The Centre will ensure improved fish welfare and sustainability through strongly reducing environmental impact by enabling reuse of waste nutrients, and minimize the risk for escapes or exchange of pathogens with wild salmonids. The willingness to invest in CCS will be assured by innovation of profitable systems by increasing feed efficiency, and substantial improvements in fish survival and welfare. Finally, CtrlAQUA will strongly contribute to economic and social sustainability for the Norwegian society, since CCS technology will contribute to making the vision of an eight-fold increase in value creation from aquaculture possible. Thus, CtrlAQUA will lead to a research-driven paradigm shift in the Norwegian aquaculture industry.