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reLAKSation no 1125

What they don’t tell you: On May 17th, Marine Scotland published the salmon and sea trout catch data for 2022. It was published without any fanfare and not even the usual advisory email. It came with a statement saying that this was all the information available, and the next update would not be until 2024.

The usual two summary sheets, one for salmon and the other for sea trout have been merged into one and this tells us that a total of 42,204 salmon were caught by rod of which 1,461 were retained. This equates to about 3% of the total catch.

Sea trout catches totalled 14,509 of which 1,372 were retained. A further 8,069 finnock (small sea trout) were caught of which 133 were retained.

By comparison, the salmon catch for 2021 was 35,693 fish whilst 12,636 sea trout were caught with an additional 6,067 finnock. In 2021, 1,619 salmon were caught and killed whilst the numbers of sea trout and finnock caught and killed were 1,600 and 267 respectively.

Marine Scotland also provide a little information about the number of spring salmon caught which is expressed as a percentage of previous catches and is relatively meaningless as the spring catch is now such a small part of the total catch.

Finally, Marine Scotland say that the total reported catch of salmon is the fourth lowest since 1952 but it is an increase of 16% compared to 2021.

In addition, to the summary review of catches, Marine Scotland also update the spreadsheet detailing the numbers of rod caught fish from each of the fishery districts. Although I would like to see catch data provided for individual rivers, the spreadsheet does provide some detailed data.  I am always surprised by how little analysis Marine Scotland undertakes from this data and because I conduct these analyses myself, how little effort it takes to obtain some key information.

Given the amount of time and effort Marine Scotland invests in researching and developing policy on salmon farming, it does seem odd that they do not analyse the catch data specifically in the areas where salmon farming is conducted. After all, if, as Marine Scotland Science clearly states: “the body of scientific information indicates that there is a risk that sea lice from aquaculture facilities negatively affect populations of salmon and sea trout on the west coast of Scotland”, then this negative impact should be apparent from the catch data.

This data relates specifically to the areas where salmon farming occurs, not the west coast as a whole. In 2022, 3,807 salmon and grilse were caught from rivers around salmon farms. This compares with 2,756 fish in 2021. This represents an increase of 1,051 fish or 38%. At this point it is worth mentioning that fish catches in non-salmon farming areas also increased, but by just 12%. (combined 16%).

More interestingly, the number of salmon and grilse caught and retained (killed) increased from 66 fish in 2021 to 112 in 2022. For sea trout and finnock, the numbers are 188 and 163 respectively. The fall in the number of sea trout is accounted for by a reduction in the killing of the much smaller finnock. The number of sea trout killed is relatively similar for both years. It seems that the Scottish Government’s call for restraint on the killing of wild fish for sport has not been heard in the rural areas. The total number of wild fish killed across Scotland is 2,922 fish or about 4.5%. It still remains a puzzle why, when the wild fish lobby says that wild fish are in crisis, they continue to kill any of these fish, especially on the west coast.

However, the real message from this catch data is that based on Marine Scotland Science’s estimation of stock size, then the Aquaculture Zone wild salmon population, which according to an anti-salmon farming critic from the angling sector, stood at 20,000 fish has now increased to over 38,000 fish.

Is it not surprising that no-one other than myself bothers to analyse this data because clearly, it doesn’t support the many claims made against the salmon farming industry. Relying on the science is one thing but looking at the hard evidence is something very different.


Escapes again: Mention was made again during the recent Scottish Parliament Rural Affairs Committee of the possibility of financial penalties being imposed on salmon farming companies that allow their fish to escape. This is because as the anti-salmon farm lobby would have everyone believe, farmed salmon which escape and then breed with wild salmon produce offspring that risk undermining the genetic integrity of the wild salmon stock. They argue that aggressive farmed salmon will displace wild salmon during breeding, but their offspring will be weak and inferior and consequently, the salmon stock will head towards extinction.

There are research reports that support this view such as one from the Norwegian Institute for Nature Research (NINA)

Unfortunately, it seems that not many of the wild fish lobby nor some of these scientists have heard of Charles Darwin and his theories about survival of the fittest. If the offspring of these very rare mating are weak and inferior, then they won’t survive to pass on their genes. In addition, most escaped salmon swim out to sea never to be seen again.

Now, a new paper that is in the process of publication and co-authored by two of the authors of the NINA report appears to question the view that changes to salmon populations are due to the impact of farmed salmon escapes. report about a new study that suggests that changes to the genetic makeup of wild salmon populations may have been brought about by changes in the environment.

The paper is available as a preprint and is titled – Overruled by nature: A plastic response to an ecological regime shift disconnects a gene and its trait.

The researchers compared the genetic material from 1,500 salmon fished during 1983/4 with salmon caught in traps between 2013 and 2016. They found that the share of grilse fell from 63% in the 1980s to 34% in 2010s. For females that drop was from 68% to just 8% whilst males fell from 75% to 56%. The researchers concluded that the genes that control sexual maturation were overridden by environmental changes in the ocean. They say that the impact of farmed salmon escapes could not explain the observations.

The researchers conclude that the salmon populations in the North-East Atlantic were subjected to an ecological regime shift leading to consistently reduced growth rates and increased age at maturation. They say that the growth driven plasticity has completely by-passed the combined influence of the two key genes for maturation.

Aquablogg asks whether the scientists who previously promoted the claim that local adaption to a specific home river and that these unique genetic pools are being damaged by escaped farmed salmon now correct their previous assertions. We can live in hope! At the same time, there should now be a major rethink about why salmon farmers should be penalised when escaped fish have such minimal impact on wild stocks, if any.


Rural Affairs: It struck me as I watched the Scottish Parliament’s Rural Affairs Committee meeting on salmon farming that here was a group of people talking about an important part of Scotland’s rural economy and community and yet there was not one representative from that sector present who could respond to questions or correct any misleading information. The Cabinet Secretary was accompanied by two civil servants who work on aquaculture issues, but they do not represent the industry. They also rely on advice from other parts of the civil service to help form policy.

However, as I have discussed previously, this advice can be questionable. This is certainly the case in relation to sea lice. I would argue that Scotland is heading down a pointless path to try to protect wild salmon with the forthcoming introduction of SEPA’s sea lice risk framework. In the most-simplest terms, how can sea lice be a risk to wild salmon when Marine Scotland Science can’t actually find any in the sea, even though their modelling predicts exactly where these sea lice should be?

Although open discussion through Parliamentary Committees is an essential part of Government, the lack of anyone with specific knowledge was sadly apparent. One example relates to sea temperatures and whether the Cabinet Secretary should be instigating plans for when climate change impacts the salmon farming industry. A question was posed that suggested that when sea temperatures hit 18oc salmon will stop feeding and at 21oc they will start to die.

There has been some discussion about salmon freshwater subjected to increased temperature, hence plans to plant thousands of trees, although there has not been much discussion yet as to whether anglers should stop fishing if the water temperatures get too high.

However, the temperature of the sea is a different matter. Average temperatures for the sea off Oban are shown in the following graph with a maximum of 14oc. A report commissioned by the UK Government with reference to biological responses to ocean warming suggests that sea temperatures have already risen by 0.7oc over the last 100 years and predicts rise in global sea temperatures of 0.8oc by 2050 and 1.2oc by 2100.

However, what is really clear is that if sea temperatures should reach 21oC and salmon start dying, the whole Scottish marine ecosystem will have already suffered catastrophic changes that dying salmon will be the last of the Scottish Government’s concerns.

Another question posed to the Cabinet Secretary as what local communities can do to ensure that the salmon farming industry does not completely wreck the inshore waters of the west coast? Perhaps the first thing that such communities could do is to provide some real evidence that salmon farming is wrecking any part of the west coast at all. Given that the industry covers an area equivalent of two eighteen-hole golf courses, it would seem extremely difficult to for the industry to wreck part of the coast let alone the whole coast.

I appreciate that MSP’s receive much correspondence about the impacts of salmon farming but as Professor Griggs observed these can be entrenched polarised views. Perhaps MSPs might encourage discussion and debate between their constituents and the industry as a positive way forward rather than allow these polarised views to persist in the Committee room.


Protest: The Sustainable Aquaculture Innovation Centre held a conference in Glasgow last week. I was unable to attend due to a prior commitment but one person who said that he was going to be there was anti-salmon farming campaigner Don Staniford.  On April 6th, he tweeted; “Please join a protest against welfare abuse of salmon farms – meet outside the Technology and innovation Centre in Glasgow on 17 May (from 8.45 am). I am reliably informed that Mr Staniford failed to appear, as did anyone else.

A protest did occur the previous evening when a single lady in a swimming costume appeared with a banner saying ‘Silver Swimmer says no Fish Farms’.

However, the real point is that whilst there is a very vocal minority against salmon farming, seemingly none of them feel strongly enough to get out from behind their computers and express their views in person. The planned protest simply failed to materialise.

MSP’s should take note.