Wrong fish: Fish Farming Expert reports that Salmon Scotland sent an open letter to the Convenor of the RAIC Committee highlighting that mortality had fallen across Scottish farms in 2023, but this improvement was not reflected in the committee’s final report. Salmon Scotland also pointed out that when there are problems in terrestrial agriculture, there are calls for governmental support and funding yet when it comes to salmon farming, there are no such calls, only continual criticism and demands for increased regulation.
It should not be forgotten that various Parliamentary inquiries were triggered by a petition from Salmon & Trout Conservation about the impact of sea lice on wild salmon stocks. The latest inquiry spent a lot of time discussing sea lice infestation on farms, yet the alleged impact on wild fish was not discussed. This is despite having Dr Alan Wells, the head of Fisheries Management Scotland as the sole witness for over an hour during one session. This would have been an ideal opportunity for the committee to learn exactly what impact the salmon farming industry has on wild salmon. Yet I suspect that Dr Wells would not have been able to provide any actual evidence on wild salmon mortality due to the impact of salmon farms. This is because any link is totally conjecture.
Whilst salmon farmers are expected to provide almost continual data on the status of farmed salmon, data about the wild salmon sector only appears when the wild sector feels it is ready to release it and then they never seem to be in any hurry.
Every year I comment on the fact that data on salmon catches takes at least five months to be processed. This is despite the fact this data is used to estimate the size of the salmon stock. In this day and age, there seems no reason why catches cannot be reported at least weekly and then annual totals be provided within a month of the season ending. How can the alleged impact of salmon farming be measured if this data is not published in good time. It already seems madness that the new fishing season is underway before the previous year’s catches are published. However, as Dr Wells told the committee, angling’s impact on wild salmon stocks is only one percent. When a scientific paper was published in 2013 claiming that the impact of sea lice on salmon farming was around one percent, there was a massive outcry because anglers couldn’t believe that there was such a small impact. This is despite actual evidence that shows this figure is probably correct. By comparison, it is difficult to understand how the premature deaths of nearly 6 million wild salmon and sea trout by anglers, as confirmed by the Scottish Government data can be described as a one percent impact.
Salmon farming has been blamed by the wild fish sector because back in the late 1980’s some wild sea trout were observed with high lice counts. Since 1997, the Scottish Government and the wild fish sector have been monitoring sea trout for lice counts but the conclusions drawn have been extremely tenuous. In 2023, the lice sampling by the Fisheries Trust biologists continued until the end of August except for one sampling that took place early in September. Presumably sampling occurred over the same period in 2024, however Fisheries Management Scotland have yet to publish the 2024 data on their website. It seems that as they feel the narrative against salmon farming is so strong, the provision of any up-to-date data is no longer required.
What is increasingly apparent is that the RAIC committee inquiries have been directed at the wrong fish. It is not farmed salmon that should be the subject of an inquiry but the wild fish. The committee should be asking what the wild fish sector has done over the last fifty years to try to halt the decline in numbers of returning wild salmon except to continue killing them.
Unsettled: In this issue of reLAKSation, I highlight two new papers that remind me that the science of sea lice is far from settled as the Scottish Government’s Marine Directorate claim it is.
One: In the last issue of reLAKSation I mentioned a new, soon to be published, paper from Canada that is effectively a critique of a review paper by Martin Krkosek and 15 others including anti-salmon farm activist Alexandra Morton. Their paper appeared in a special issue of Science Advances that was inherently negative towards aquaculture.
This week I received another paper that has just been published in Aquaculture Environment Interactions. This paper revisits sea trout in the River Erriff in Ireland by way as a comment on a paper by Dr Paddy Gargan of Inland Fisheries Ireland and others that was published in the same journal in 2016.
Whilst the forthcoming Canadian paper, now available as a preprint, has reviewed a paper from last October, the newly published Irish paper has reviewed a paper that was published nine years ago in December 2016. This may seem to be now somewhat out of date, however I have been led to believe that the paper was first submitted in 2017, soon after the original paper was published. This is well before the stated submission date of 2021, and even from then the paper has taken three years to come to publication. The question is why has it taken so long to come to print? The obvious reason is that sea lice reviewers come from a very small clique of scientists, most of whom have direct involvement in the research and thus are rarely favourable to papers that question their science. I know from my own experience that this is very much the case.
The 2016 paper states that the sea trout population in the river Erriff was analysed over a twenty-year period during which important life history changes were observed. The most dramatic of which occurred immediately after the commencement of salmon farming in the local estuary with significant decreases in number of sea trout caught by rod and line. In addition, they found a significant positive relationship between the number of sea lice in the local salmon farm and the number of lice found on sea trout in the local river. They concluded that the introduction of salmon farming most likely contributed to the observed changes to the sea trout population.
The findings of the new paper can be summed up very simply. The authors of the 2016 paper have not actually linked the collapse of sea trout to the presence of sea lice or salmon farming. The author of the new paper is clearly well qualified to comment on these changes as the 2016 paper includes an expression of gratitude to him for providing detailed assessments of the local sea trout stocks.
I am not going into details of the paper here, but the reality is that any linkage between the collapse of sea trout stock and the presence of salmon farming is simply conjecture. As in Scotland, observation of reduced catches, were at that time, simply blamed on the arrival of salmon farming to the west coast. That is now over thirty years ago, and I have yet to see any conclusive evidence of the link. In recent years, any evidence that has been provided comes from models and not the real world. Unfortunately, Model Land is now firmly established within SEPA’s Sea Lice Risk Framework, which is why they continue to refuse to talk to real world people.
What the abstract of the new paper highlights are errors on data presentation, interpretation of the data and weakness in the methods used. I have met the lead author Paddy Gargan more than once and so do not feel that I am speaking out of turn when I say that the claims made in the paper must be cause for concern, not about the science but because Paddy Gargan is listed as the coordinator of the NASCO Expert Group assigned to review the latest knowledge of the impacts of sea lice and farmed escapees.
The NASCO study was highlighted to me by Baroness Hayman of Ullock, the DEFRA Parliamentary Under-Secretary of State, in a letter in which she said that the study would use a weight of evidence approach to explore the presence and magnitude of any impact salmon aquaculture is having on wild populations. However, in my opinion, the researchers being coordinated by Paddy Gargan, with one possible exception, all have a very anti-salmon farming stance. None seem willing to engage in discussion of the science and evidence that shows salmon farming impacts are extremely small if at all.
Although it is not stated, NASCO are just another mouthpiece for the angling sector. In their twenty-year milestones and next steps document, NASCO mention a range of threats including salmon farming, Gyrodactylus, and mortality at sea. but do not include exploitation by rods as a threat. I cannot forget the 6 million wild salmon and sea trout that have been killed by rods in Scotland since 1952 and yet merit no mention at al. NASCO are viewed as a worthy organisation but if they want to protect wild salmon, then they should consider all impacts on wild salmon, not just those that involve blaming others.
I believe that Paddy Gargan has now retired form Inland Fisheries Ireland, an organisation that helps angling be recognised as a valuable national asset through its promotion as a leisure pursuit. They also have a protection role, but they seem to care very little about protecting salmon from angling, Finally, IFI also promote conservation as well as carrying out research including exploring environmental issues that have an impact on fish. As can be seen this is mainly focussed on researching the impacts of salmon farming.
This paper is not the first time that Paddy Gargan and Inland Fisheries Ireland have been involved in some contentious issues. In 1997, Professor Ian Cowx of Hull University was commissioned to conduct an independent review of sea lice sampling by members of IFI. It seems that records of sampled fish did not match with other data submitted. The overall conclusion of the report was that there were many problems and discrepancies in the data collection, collation and analysis although Professor Cowx did not apportion blame to any single source.
A final point of interest is that the last-named author on the 2016 paper was Ken Whelan who was amongst other things research director of the Atlantic Salmon Trust for thirteen years. The Atlantic Salmon Trust state on their website that:
‘‘It is beyond doubt that salmon and sea trout can suffer from the presence of open pen salmon aquaculture, due primarily to a combination of harm from sea lice infestations and interbreeding with farm escapees. These problems have severely impacted individual populations of wild salmon and sea trout.
Looking at the conclusions of the new paper, I would suggest that it is time that the Atlantic Salmon Trust revised their view on salmon farming and look elsewhere. The Missing Salmon Alliance website describes the AST as
“The Atlantic Salmon Trust (AST) was founded in 1967 in response to growing concerns about over exploitation of wild salmon”.
Perhaps they should be asking the question whether in these times that salmon have been classified as endangered, there should be any exploitation taking place at all.
Two: The Scottish wild salmon strategy (22 January 2022) includes a review of the pressures on wild salmon. These include:
“Salmon are consumed by many species of predator. Those considered to present the greatest risk include other fish (e.g., trout, pike, eels), birds (e.g., cormorants, goosanders) and mammals, including seals. The effects of predation can be exacerbated in the presence of anthropogenic pressures including barriers and impoundments that alter habitats and disrupt salmon migration.”
This statement reflects that the wild fish sector who drew up the strategy seem unable to look beyond the river mouth except in the case of salmon farms. Predation by seals does occur outside rivers but also very close to river mouths, Yet, once outside the immediate environments of the river estuaries, most things that happen in the sea are rarely considered. The view is that there are pressures that can be addressed and pressures that cannot. Those pressures that cannot be easily sorted and typically ignored. Yet, knowledge and understanding of such pressures is just as important as being able to remove a dam, plant a tree or blame salmon farming. Salmon have been in decline for over fifty years, and we still don’t know why.
A new paper from Norway is now adding to this knowledge. In this research, 70 tagged smolts were released at various points in the fjord system around Osteroy in Western Norway, part of which is a National Salmon Fjord where salmon farming is prohibited.
Seventy three percent (73%) of the smolts were eaten by predators before they left the inner fjord. However, the paper does not hypothesise as to which predators are consuming the fish except to say that cod and pollock tend to congregate under nearby salmon farms. The paper states that there are five salmon farms with a total allowable biomass of 13,650t between the first smolt release point and the outer fjord although the three highest up the fjord were fallow during the study.
It is not surprising that salmon farms are highlighted as attracting cod and saithe because the lead author of the paper is on the Sea Lice Expert Group and the Scientific Committee for Salmon Management. In 2023, he authored a paper that claimed lice induced mortality had been underestimated in the River Vosso. Now it seems that the high levels of mortality previously attributed to sea lice could be due to predation by marine fish species. The latest Norwegian Aquablogg commentary asks why the lead author, and his colleagues had not noticed that most of this mortality occurred during the early part of the long migration away from the Vosso.
Aquablogg also highlights that the estimated mortality is modelled and does not take into account other factors that might affect wild salmon. This paper shows that an important factor in mortality is predation within the fjords, something that was actually known about during the 1970s. According to Aquablogg, it was shown that smolt survival increased 2-3 times when the smolts were released past what is called in Norwegian the Seilbelte, which is an area rich in marine fish. However, Aquablogg says that the new generation of scientists were unaware of this and were subsequently convinced by anglers, based on no science at all, that the problem for smolts were sea lice from the newly established salmon farming industry. Since then, as Aquablogg rightly suggests, the sea lice story has dominated everything yet has been based on very little actual evidence.
As mentioned, the new paper does refer to salmon farming but if cod and saithe congregate under fish pens to eat surplus food etc, then they were unlikely to leave this food bounty to go off in search of salmon smolts.
Photo Aquablogg
H2O2: Wild Fish continue their crusade against the salmon farming industry with the publication of their new report The Reality Gap. Their key findings include that salmon farms reported the use of 1.38 tonnes of Hydrogen Peroxide during 2023. Wild Fish say that Hydrogen Peroxide is highly damaging to kelp and shrimp, although the science is not clear.
Wild Fish talk about misleading consumers, but they too are quick to mislead. 1.38 tonnes of H2O2 might sound a lot but typical annual UK usage is 110,000 tonnes much of which is used in wastewater treatment plants as a disinfectant. Salmon farms use only a tiny amount of the total that is discharged into the environment.