Regress: A special issue of Science Advances has been dedicated to the subject of aquaculture but this issue would have been better published under the name of Science Regression. This is because the editors have collected together eleven papers that have all adopted a negative view of aquaculture covering subjects including the spread of pathogens, how the need for fishmeal is depleting wild fish stocks, animal welfare and the moral reckoning of farming fish. Most of the authors are associated with publishing critical reviews, especially of salmon farming and thus this special issue has nothing positive to say about the farming of fish at all. There is much that can be written to counter the many claims made in these papers, but I would like to focus on just one. This is ‘Pathogens from salmon aquaculture in relation to the conservation of wild salmon in Canada’ which has been written by a group of 16 authors, led by Martin Krkosek, a long-time associate of salmon farm critic Alexandra Morton, who is also listed as one of the authors.
The paper considers the impact of three pathogens, one of which is sea lice. However, the evidence cited that sea lice actually have an impact on wild salmon is actually rather weak. Firstly, the paper states that:
“Meta analyses of large-scale manipulative filed experiments in Europe have shown sea lice to be associated with reduced survival and recruitment of wild salmon.”
The paper cites two other papers as part of the evidence. The first is by Vollset et. al. (2016) which analysed a range of other works rather than attempting to conduct their own investigation. It really is just playing with the statistics. One of the listed authors is Martin Krkosek, lead author of this new paper. The second paper referenced is by Krkosek et. al. (2013)
The new paper then continues that “In BC stock-recruit fisheries models that include covariates for sea lice on farms near spawning rivers, or on juvenile wild salmon have provided evidence that sea lice on salmon farms are correlated with reduced population productivity for pink and coho salmon”. This claim is supported by three references. These are Krkosek et. al. (2011), Connors et. al. (2010) and Peacock et. al. (2013) in both of which Martin Krkosek is listed as the second lead author.
I sense a theme running through this evidence with Martin Krkosek, the lead author of this new paper, citing his own work as the only evidence that sea lice have an impact on wild salmon. Additionally, all the main papers were published over 10 years ago. There seems to be a lack of any recent evidence to support these claims. This is not surprising because having failed to provide convincing evidence about sea lice, Martin Krkosek’s mentor Alexandra Morton started to highlight scare stories about other pathogens allegedly having an impact on wild fish.
What Martin Krkosek has failed to recognise is that the real evidence collected in BC does not support his ‘science’. Analyses of sea lice infestation collected over twenty years from a variety of different sources shows that the majority of wild fish sampled (72.6% of 320,177 fish) were lice free and just 3% carried 5 lice or more. The interesting aspect of this work is that one of the sources of this sampling was the Salmon Coast Research Station (SCRS). This field laboratory had been founded by Alexandra Morton and at which Martin Krkosek was its first grad student. The SCRS contributed a total of 44,529 or 14% of the wild fish samplings to the wider analysis. What is interesting is that analysis of the SCFS sea lice data does not support the claims made by Martin Krkosek and four of the other directors of the Field Station.
In fact, six of the paper’s authors have affiliation to the SCFS including its founder, Alexandra Morton.
What is also interesting is that three of these authors have affiliation with the Pacific Salmon Foundation (PSF) along with four others meaning a total of seven of the authors have a connection to this organisation.
Prior to the publication of the Science Advances special issue, I had already intended to write about the state of salmon in BC because the PSF has recently published its 2024 of the State of Salmon report. This evaluates the current status of all six species (including steelhead) found along the Pacific seaboard. The PSF has provided a summary of four key findings for 2024.
- Declines in Pacific salmon abundance are widespread across BC and Yukon with 70% of the 41 region species combinations below their long-term average abundance.
- Chum salmon are doing the worst with abundances with the long-term average in all regions and across the whole Pacific rim.
- Northern regions have experienced the most widespread salmon declines including Yukon, Northern Transboundary, Haida Gwai and Central Coast.
- There are recent signs of recovery in some regions that provide hope for the future of salmon for example abundance of coho salmon in the Fraser River has increased above the long-term average for the first time in decades and Chinook spawners abundance around the Fraser, Vancouver Island and Mainland Inlets are above average.
The report goes into some detail for each region, but it is worth looking at the areas around where salmon farms operate, including Fraser and Vancouver Island.
As can be seen, some of the stocks are doing quite well and certainly there does not seem to be a negative impact from salmon farming. As previously mentioned, the worst performing stocks of Chum are doing badly across all of Canada and not just around salmon farms. Of course, critics will argue that much of the industry has been closed down and thus the pressure on wild fish is much less than it would have been otherwise, but these critics have never really provided any hard evidence that salmon farms were ever responsible for any negative impacts on wild fish. In BC, as in Scotland and Norway, the publication of a few images of wild fish with high lice numbers seems to be all that is required to damn the industry, despite the fact that it is entirely natural for parasites like sea lice to infest their hosts in really high numbers,
Whilst the sixteen authors of this paper are happy to point the finger at salmon farming, attempts to engage in a scientific discussion fall on deaf ears. They have their narrative and they want to stick to it regardless of how well or poorly salmon stocks are doing.
So wrong: If you read everything written, it would be easy to believe that salmon farming is the greatest environmental disaster to hit our planet since the atomic bomb was dropped at the end of the second world war. Whilst it was initially the angling fraternity that blamed salmon farming for the decline of wild salmon off Scotland’s west coast, others have jumped on the bandwagon. It is now fashionable to attack the salmon farming industry for any reason regardless of the accuracy of any claims made. It is often said that if a lie is repeated often enough it becomes the truth. Such ‘truths’ are often repeated by journalists working for both the mainstream and science press, probably because such untruths represent an easy story. This is the ‘truth’ that the aquaculture industry faces on a daily basis. However, it must be of real concern when journalists working within the fish and seafood sector also start to repeat the untruths believing that they are the truth.
It was really disappointing to read in Intrafish an article by long-time journalist Drew Cherry titled the critics are right, its time to close down salmon farms. He begins his commentary by saying that ‘A rash of stunningly bad news on sea lice should have salmon farmers around the world, not just in Norway, scrambling for solutions. He continues that even before sea lice counts hit record levels this year in Norway, financial losses from lice in the global salmon farming industry were astronomical. Drew argues that the best way for the salmon industry to secure control is moving towards semi-closed or closed containment systems.
My response to Mr Cherry is that he should go back to reporting facts and avoid expressing any view at all.
His commentary considers the move to introduce new technology which he admits will cost hundreds of millions of dollars. By comparison, I would argue that rather than rush to make such investments, the first step the industry should take is to ensure that the sea lice science that is enforced on the salmon farming industry is actually correct. Salmon farmers have seen mortality rise in recent years and at a huge cost, but in most cases, the mortality has been fuelled by the need to treat fish unnecessarily, simply to maintain sea lice at some arbitrary level set by government regulation, but which has no purpose other than to mollify the wild fish sector who have successfully deflected attention away from their own poor practices of wild salmon management.
The second step is to consider that closed containment was initially proposed by the wild fish sector for their own reasons, which certainly have nothing to do with the interests of salmon farmers. Why is closed containment considered the best option, because whilst it may remove one problem it can produce many more and for what reason?
The salmon farming industry needs a good reason to move from current forms of open pen farming, which effectively works well, if left to farmers to manage without undue interference. If the industry needs to consider new technology to improve on this successful method of production, then why not investigate technology that tweaks existing production rather thana change the method of production as Mr Cherry proposes.
I would argue that solutions are already available but perhaps with some tweaks. The issue with sea lice is that the larvae are attracted to light and thus are found towards the water surface. If they are present in large numbers, current feeding practices encourage the fish to rise to exactly where these larvae can be found.
Mr Cherry wants to convert the industry to some form of containment at huge cost but surely the simple answer is to stop the fish feeding at the surface. Long-time readers of reLAKSation may remember that this is not a new idea. Over thirty years ago, I proposed this concept, and a kindly feed equipment manufacturer made a prototype feed delivery system which worked well but at the time was never a practical option. Back then, I stressed to those who observed the prototype in operation, not to look at the equipment but simply to consider the concept. At the time, sea lice were less of an issue and the feed and farming companies were not even interested in the concept.
Now we are in 2024, the concept is more viable than ever and certainly a lot cheaper than changing the whole production method.
Surely, if fish are encouraged to feed deeper in the pens, staying out of the way of infectious lice larvae, then sea lice become less of an issue.
If any reader is interesting in watching a thirty-year-old video of the concept send a mail to relaks@callandermcdowell.co.uk and I’ll send a link.
The real problem affecting the salmon farming industry is that there seems to be an unwillingness to discuss the issues and hence the message that is sent out is that salmon farmers should listen to critics and close down the salmon farming industry as we know it today. What Mr Cherry fails to appreciate is that if salmon farms are shut down, many supply companies will follow including the news services employing journalists like Mr Cherry.
Fouled: In a previous issue of reLAKSation I discussed how the Scottish Environmental Protection Agency is to pay the Norwegian Institute of Marine Research (IMR) the sum of £200,000 to help them use sentinel cages as a way of validating their sea lice dispersal model, even though it is already clear that any data emanating from sentinel cage deployments can never be used in this way. However, a now greater concern about this arrangement is increasingly apparent. This is whether the science produced by IMR Can ever be considered impartial.
Salmon farm critics were quick to jump on a new report from IMR that stated that trace amounts of tralopyril, an anti-fouling agent, were detected in fillets of farmed salmon. Although the levels detected were extremely low, IMR have called the discovery concerning due to the lack of data on the impacts of tralopyril. They say this is because it is not naturally occurring, and no safety limits have been established for the product in human food or fish feed. According to Salmon Business, IMR say that this contrasts with other treatments used by the aquaculture industry, which have regulated safety levels. Apparently, only one study has taken place for comparison, and this was in rats. The levels found in salmon were significantly lower than that which caused any negative impacts on rats.
However, the Belgian supplier of tralopyril, Janssen PMP, told iLaks that whilst they do not question the findings of the IMR study they feel that some of the statements made by IMR were misleading. This is especially relevant to the claim that no other studies have been conducted on the product. In fact, Janssen PMP say they have carried out extensive studies to generate data documenting that the use of tralopyril is safe for the fish, for the environment, and for consumers and this data had already been assessed by the Norwegian Environment Agency. The NEA concluded that consumers exposure to tralopyril was 2700 times +lower that the established acceptable daily intake limit.
IMR had concluded in their study that there was an accumulation of tralopyril in salmon study whilst the trace levels found could not be regarded as an accumulation according to regulatory definitions.
Meanwhile, the primary author of the IMR report expressed his opinion in a commentary published by iLaks. He writes that previously no study had identified tralopyril in salmon flesh as well as in some other marine organisms. He said that these ‘alarming findings’ should be made known. He also writes that limit values have not been placed on the product in the environment and he says that there is a gap in the knowledge but that a lack of knowledge should not prevent them using the knowledge that they actually have. He argues that tralopyril belongs to a group that is an environmental toxin that is undesirable in the environment and that under unfavourable conditions, the amount of tralopyril can become very high.
He also writes that it is important that IMR publishes fresh research in areas where there are gaps in the knowledge so that both industry and the authorities can take into account what is actually known and perhaps avoid encountering the same problems that occurred with copper as an antifoulant. The commentary also says that fortunately the use of copper has declined sharply but it now seems that the alternative from Janssen PMP also has unwanted side effects.
He repeats comments made in another commentary that it is important that IMR’s integrity and trust can never be called into question and that their research is impartial. He also says that IMR has, and shall have, a free and independent role in all academic matters.
However, he also must admit, as highlighted in another commentary, that this study was part funded by a company called Netkem AS which produces copper impregnation, and who are a direct competitor to Janssen PMP. This information was included in the full report but was omitted from the press release, which is the main source of information.
Most of the criticism of salmon farming industry originates from summary press releases undermining any view that IMR are impartial. In my opinion they are far from impartial because if they were they would be more than willing to discuss issues such as the science of sea lice. Could this be because they are locked into lucrative contracts from which they want to benefit. This particular report does not mention how much Netkem AS contributed towards this research. I only know that SEPA plan to spend £200,000 with IMR due to a Freedom of Information request. If IMR are impartial, then they should be telling SEPA that they no longer rely on sentinel cage data to assess sea lice infestation as part of the Traffic Light System and thus they should advise SEPA to look for a better way to validate their model even though IMR have yet to validate their own similar model.
The problem is that this example is not just an isolated case. Another IMR study has come to light in which they looked at the ecological interactions between salmon farming and wild cod populations. Among some of the risks to wild cod identified is that the quality of salmon feed that was lost from a farm may alter wild cod’s physiological processes and cause mortality to vulnerable life stages.
The project was part funded by ‘Fram Research Program CLEAN’ who are interested in identifying the risk from stressors in the high north ecosystems. These include climate change, pollution, species invasions and human activities such as aquaculture. Of course, it is aquaculture that is highlighted in this paper from IMR.
According to Statistics Norway, in 2016, a total of 408,800 tonnes of cod was landed from Norwegian fishing boats and was the most important fishery accounting for 20% of the total catch. In 2018, the catch was 376,404 tonnes.
There is no way possible that the risk to wild cod from salmon farms can be even compared to the huge mortality of cod from fishing. Once again IMR appear to be working on a project that will always present salmon farming in a negative light. I may be wrong, but I suspect IMR have never undertaken a project criticising the fishing industry for depleting wild cod stocks in Norwegian waters. After all, I have yet to see criticism of the angling sector for continuing to kill wild salmon, despite an ever-declining population.