CtrlAqua is the Norwegian Centre for Research-based Innovation in Closed-Containment Aquaculture and is partnered by top Scandinavian universities, major players in the fish farming industry and pharmaceutical companies. CtrlAqua, who advise the Norwegian Government, has conducted 8 years of research on various types of closed containment systems.
CtrlAqua's 2022 annual report (published April 2023) and Final Report (published August 2023) very much underline the experimental nature of Loch Long Salmon (LLS)'s intended industrial-scale developments using "semi-closed" systems, one of which is going through a planning appeal process on Loch Long (Beinn Reithe), the second being that proposed for Lurignish on Loch Linnhe.
CtralAqua's press release of 24th April 2023 states "The semi-closed systems have developed a lot over the eight years, but there are still some uncertainties that mean that there is higher risk associated with working on such facilities compared to both traditional nets and RAS”. As CtrlAqua Chairperson Trond W. Rosten puts it "…semi-closed facilities at sea still have a way to go".
We would draw your attention to the following CtrlAqua Key Comments - our remarks are in italics (Long Live Loch Linnhe).
Due to the volatility of these systems, 24/7 monitoring and controlling is necessary. Operators are under a lot of pressure round the clock, and the technology is therefore especially vulnerable to human error.
Unchecked changes in oxygen or temperature levels can lead to fish sickness or even death, as happened in Clayoquot Sound in Canada where a technical failure in their experimental semi-closed containment system led to the fish dying in their own urine.
The stocking density means that the salmon are more prone to skin lesion and fin health issues, making them vulnerable to disease.
The RSPCA assured limit for stocking density in open net is 15kg/cubic metre. The density proposed by LLS in their system will be about 45kg/cubic metre.
Pathogens cannot be excluded.
The increased stocking density means that any disease may spread uncontrolled through the cages.
Sea lice are greatly reduced but not eliminated.
LLS state that the system will totally eliminate sea lice and that they will not, therefore, be applying for a chemicals licence. If they do get sea lice, eradication may require the use of chemicals, eg hydrogen peroxide, which is extremely harmful to crustaceans and humans. Note: LLS can apply for a chemicals licence after planning has been granted.
Solid waste extraction has not been adequately researched as it has not yet been implemented.
For their Loch Long proposal, LLS have obtained the necessary licence covering waste extraction from the Scottish Environmental Protection Agency known as a Controlled Activities Regulations (CAR) licence for their Loch Long proposal. However their licence application is based on mathematical modelling (called NewDEPOMOD) which does not consider the effect of the fish and water movement on the movement of the waste. Because of this, we consider this modelling to be insufficient - see references  and  below.
The inlet water is not treated. Taken from depth, CtrlAqua state only that it will contain LESS lice, LESS algae and LESS pathogens- they will not be eliminated.
Thousands of tonnes of urine will be going into the surrounding environment. This is likely to lead to eutrophication and compound the issues of algal blooms and micro jelly fish (hydrozoans) that were known to block the intakes on the same design of cage being trialled in Canada, causing mass mortalities.
Semi closed containment technology has only been successful in growing post smolts to around 500g, after which the fish are transferred to open cages to grow out.
We know that growing to harvest size is being trialled, however we have no data as to the success or commercial viability of these projects. Transferring such huge volumes of fish to open nets will have a cumulative effect on all the existing issues relative to open net – pollution, escapees, lice, disease etc.
Developers of semi-closed post-smolt production at sea have not had the same economic benefits and predictability as those who have built RAS on land.
There is the added benefit to land based RAS that pollution is completely kept out of the marine environment.
As far as we can assess, there is no independently verified available data to evidence the commercial success at scale of semi-closed containment systems, as they have so far only been trialled on a small scale due to the experimental nature of the technology.
 Dr. John Campbell C. Env., C. Chem, FRSC has written very detailed observations relating to these concerns in his correspondence reference the Loch Long (Beinn Reithe) proposal
 The only available data that we have been able to find on waste extraction efficiency are to be found in the Akvafuture 2020 Report (Akvafuture is another Norwegian company doing small scale trials on semi-closed containment). After two years of experimenting, the report shows that they achieved between 6-13% solid waste extraction. Loch Long Salmon say (this has not been verified) that after a further 3 years of research, they are now managing to extract 40% of the solid waste using their proprietary system. Loch Long Salmon’s proposed system is still on the drawing board so they have a long way to go before reaching the 85% that they claim.
Here are relevant excerpts, with highlighted sections to note:
• (Annual Report) Page 8: “RAS has almost become an off-the-shelf product, while semi-closed facilities at sea still have a way to go. “ According to Chairperson Trond W. Rosten, this is the status after eight years of intense research conducted on fish in closed fish farms in CtrlAQUA.
There are several suppliers of semi-closed systems at the Centre, such as Aquafarm Equipment, FishGLOBE and FiiZK. “The semi-closed systems have developed a lot over the eight years, but there are still some uncertainties that mean that there is higher risk associated with working on such facilities, compared to both traditional nets and RAS.”
• (Annual Report) Page 11: “At the same time, there are still problems associated with skin and wounds that have not yet been resolved."
• (Final Report) Page 8: "...most of the systems are still at the pilot stage."
• (Final Report) Page 13: “There are still developmental needs to complete the systems to become “off the shelf” ready, especially for the semi-closed systems.”
• (Final Report) Page 13: “Also there is the need for further closing the systems with the development of treatment of inlet and discharge to prevent pathogens and pollution.”
Facts about closed containment systems
“In closed-containment systems at sea, most systems are still semi-closed because they do not treat all inlet water or collect waste. Many farm smolt and potentially keep them there until they weigh 500-1000 grams. In practice, they currently work as an intermediate stage for post-smolt weighing <500 grams.
The advantages of such closed-containment systems at sea are that they may take in a lot of good seawater from the depths where there are less lice, less algae and fewer fish pathogens compared to the surface. A sealed wall separates the sea environment from the fish on the inside of the facility and prevents fish from escaping and lice from entering.”
The report then goes into detail re Preventive Fish Health and Technology & Environment which are being researched and are by no means optimised yet. Sea lice issues in SCCs seem unquestionably to be much improved but are not eliminated as claimed by Loch Long Salmon.
The SCCs are very much still in trial mode and as Rosten states …” have a long way to go”.
NB the FiiZK Certus SCC systems that LLS have so far been suggesting for deployment at Lurignish on Loch Linnhe have had various problems including two cages completely collapsing in November 2022 whilst being delivered to Norwegian salmon farming company Osland Havbruk. The two that were already on site were also rejected due to structural issues.
CtrlAqua works together with Scandinavian Universities and advises the Norwegian Government. Partners who have contributed to the Research over the 8 years include FiiZK and FishGlobe who have been mentioned by LLS.