NASCO follow up: Unusually, this year’s NASCO meeting attracted the interest of TV News, and the story has been posted on You Tube https://www.youtube.com/watch?v=8AcZNhTU9PM and lasts for two and half minutes. Included is an interview with the new head of NASCO, Dr Cathal Gallagher who explained that the meeting is where Governments outline their conservation policy aimed at protecting wild salmon. I mentioned in the last issue of reLAKSation that the Scottish Government failed to submit their plans in advance of the meeting.
Dr Gallagher told the reporter that the main impacts on wild fish are sea lice emanating from salmon farms and introgression from breeding between wild and farmed salmon which affect their genes. In response, Salmon Scotland told STV News that it is wrong to suggest salmon farming is driving the declines with steep decline on Scotland’s east coast and in England where there are no salmon farms. They continued by saying that unsupported allegations risk distracting from the need to address the many pressures affecting wild salmon.
The main question is that if Dr Gallagher and NASCO believe that salmon farming is the main driver of wild salmon declines, then why won’t they engage with the industry to discuss the impacts. Even though my own journey into wild fish interaction began with a debate with the then head of NASCO in 2010, NASCO have increasingly refused to discuss salmon farming with the salmon farmers, Last year they published their own review of the impacts of sea lice and escapes but it was extremely selective in the use of science. At the time, the head of the International Salmon Farmers Association was not allowed to address the meeting.
It is of no surprise that NASCO don’t want to talk about salmon farming, because despite talking about being an Inter-Governmental organisation, they are really just another representative group for salmon anglers. It is only necessary to look at the list of 40 non-governmental organisations that are accredited observers to see that they are almost all angling organisations https://nasco.int/about/nasco-observers/ . It is time that NASCO are called out for what they really are, not some organisation that really cares about the conservation of wild salmon, but an organisation that wants to conserve wild salmon so anglers can continue to catch and even kill them for sport.
Whilst Scotland failed to submit a conservation report to the latest NASCO meeting, it is interesting to refer to a document from the 2025 meeting for a special session of successful actions. In their document, the Scottish Government’s Marine Directorate stated three successful actions towards the pressures affecting wild salmon.
- A new risk assessment framework was introduced in February 2024 to manage impacts of sea lice from farmed fish on wild salmonids. It is interesting that the Marine Directorate consider this to be a success because like the angling fraternity, they too have consistently refused to look at evidence that shows sea lice are not the cause of the declines. At the same time, they appear to favour the views of the wild salmon sector as illustrated by the next two actions.
- The retention of all salmon in coastal waters continues to be prohibited. This prohibition began in 2016 nearly ten years ago after campaigns by the angling sector to stop such exploitation and since then salmon stocks have collapsed. How can this be considered to be a success?
- Vulnerable fish stocks are protected through statutory conservation measures to ensure no salmon is killed before April 1st (although 21 fish are recorded as having been killed before this period, but it wouldn’t be surprising if more have been despatched without any record). After April 1st rivers are reassessed annually as good, moderate or poor to manage exploitation by rod and line. In addition, there is now a well-established culture of catch and release (96% released) yet despite all these measures salmon catches are at an all-time low.
In my opinion, the problem for wild salmon is that the emphasis is too much towards wild salmon fisheries than the fish itself. The message from the above success stories is that they simply reflect the views of the angling sector rather than what either science or common sense would say. The successes are to hit the salmon farming industry with increased regulation and penalise a successful Scottish industry as well as banning exploitation by nets but not by rod and line. As I have repeated every year, the salmon conservation rules are designed to protect angling interests, not the salmon. This is ultimately why salmon catches are at the lowest number they have ever been.
I have recently become aware that Marine Directorate scientists have conducted some new research on sea lice infections. I don’t know what this work entails but surely, the priority for Scotland is to try to halt the decline of wild fish. How investing in more sea lice research will achieve this is unclear. Surely, they should be researching the real reasons why wild salmon are in crisis, not spending time and effort in trying to prove that sea lice are to blame, especially as they say, there is now a framework in place to regulate sea lice in Scottish seas – even though this framework will do absolutely nothing to protect wild salmon.
It’s time that the Marine Directorate engaged in a better dialogue with the salmon farming sector rather than listen to the vested interests of the salmon anglers, whether it is NASCO or any of the many Scottish observers to the NASCO meetings.
Dissent: Because the angling sector tends to hear only one point of view, there is almost unanimous dislike of the salmon farming industry by anglers. It is almost impossible to get any coverage in the angling press that salmon farming is not responsible for the current state of wild salmon stocks and equally, the representatives of the sector are not interested in hearing that they may be wrong. It was therefore very refreshing to read a commentary in Ilaks from someone who describes himself as a passionate salmon fisherman. He titled his commentary -The Great Salmon Fraud.
He begins:
“Every spring, the same ritualistic spectacle repeats itself in the Norwegian media. The headlines shine at us with words like “crisis,” “collapse,” and “extinction.” The Environment Agency applies panicked emergency brakes and closes rivers overnight, anglers are furious, and scientists point their entire hand at the fish farming industry’s cages. The narrative served to the public is simple, linear, and apocalyptic: The fish farming industry has halved the Norwegian wild salmon population, and the species is heading over the cliff.
There is only one problem with this narrative. It ignores the biology of salmon, distorts historical facts, and hides the management fraud that we actually have full control over solving.”
What this passionate angler suggests is a primary factor in the decline is that a perfect storm occurred in the late 1980s when ocean currents changed, temperatures rose and the population of redfish collapsed. It was these redfish that provided food for the salmon smolts, and their loss meant that salmon smolts starved to death.
At the same time, the parasite Gyrodactylus salaris was inadvertently spread into Norway’s rivers in the early 1980s and one of the actions to limit its impact was the closure of about 170 local hatcheries which had released about 15 million salmon fry a year to help boost salmon catches. The closure meant that the loss of these hatchery fish was first noticed in the late1980s just as smolts were starving out at sea.
The commentary continues that if there are hundreds of millions of farmed salmon pumping out sea lice, why have wild salmon not been eradicated, which is a valid question. Instead, the point is made that Norway has fallen in love with symptoms treatment with a focus on discussion of quotas, catch and release as well as counting lice until they are blue in the face while completely ignoring the underlying reasons why salmon are in decline.
The commentary concludes that the time has come to shift the focus from restriction and scaremongering to active action to halt the decline. In this case the idea is to ensure that as many fish leave their home rivers in the best of health and able to withstand the rigorous journey ahead. I am not sure that if this is the only answer, but there does need to be such debate rather than the usual finger pointing.
CSA continued: Following on from the RCT debate covered in a previous reLAKSation, the Chief Scientific Advisor to the Marine Directorate moves on the specific question of the Jackson Krkosek debate. He says that quantification of sea lice impacts on wild salmon has generated significant academic debate centred primarily on methodology approaches to analysing randomised control trials RCT data. This discourse has evolved from disagreements about statistical methodology and interpretation – there is no clear ‘right’ or ‘wrong’. However, there is a wrong when the statistics leads to the publication of misinformation in mainstream wrong.
The difference between the two camps (Jackson and Krkosek) is a large number (30% mortality due to sea lice) but is extremely simple to explain.
Jackson focused on the number of fish returning compared to how many released for each group and then compared the two groups, whilst Krkosek only considered the difference in how many returned between the two groups.
The CSA includes a graphic in his commentary to illustrate his thoughts. The same graphic can be used to demonstrate the difference between the two groups. The image shows that just one fish out of a hundred dies from sea lice (black square). Jackson looks at the comparison of the black square to the grey squares whilst Krkosek looks at the relationship with the white squares. It really makes no difference in the interpretation as one black square remains the fish deaths in both analyses. It is simply the way that they are presented that differs with one trying to overstate the problem compared to the other.
The CSA has followed the example of Krkosek by saying mortality is one out of six fish or 17%. He says is a realistic representation of the mortality due to sea lice, but I suspect he has been swayed by Gargan’s 2025 paper which suggests 18% reduction in recruitment due to sea lice, which is similar to 17%. The CSA has highlighted the Gargan paper more than once so appears to give great store to it. Unfortunately, I do not have the same confidence,
The reality is that 17% of fish do not die due to sea lice. This is the same confusion that occurred in 2013. At that time, the Irish sector put out a video explaining the differences and the confusion. This was posted on the Vimeo website and used to be easily accessed but now not so and consequently, I have reposted it on You Tube.
https://www.youtube.com/watch?v=kft00UJTtpM&t=2s
For those who prefer to read the explanation, I have copied the main points of the narrative as follows:
” When wild salmon smolts migrate from the river to the sea they encounter many forms of marine life not found in the rivers where they spawn. Among these natural marine life forms is the sea louse. Whilst the name might not be very pretty the sea lice is part of the natural marine ecosystem, and it lives on the skin of the salmon, and it is perfectly for salmon and other fish to have sea lice on their skin whilst they are at sea. However, they disappear once salmon swim back up the river because sea lice as the name suggests cannot live in freshwater.
Salmon and sea lice have co-existed for millions of years. However, whilst mature salmon can accommodate sea lice without any ill effects, the younger juvenile salmon or smolts can under certain circumstances be over-burdened.
Over the past thirty years, the number of salmon returning to our rivers have declined quite significantly. Up until the 1980s the numbers returning were between 20 and 25%. Today that number has fallen alarmingly to the extent that out of every 100 salmon leaving only about five come back. This has worried fishery scientists who have been searching for the cause of this decline. Some researchers have put forward a theory that sea lice infestation of the smolts could be a major factor in the decline of marine survival. It was also claimed that this was due to an increase in sea lice populations at river mouths due to salmon farming, If it was found to be true this would have serious implications for the survival of the Atlantic salmon as a wild species.
As the State Agency responsible for marine science and research in Ireland, the Marine Institute decided to test out the theory. It carried out a very long and very large series of experiments to test the impact of sea lice on the young salmon. It involved 350,000 salmon smolts released into eight different rivers over a nine-year period. One half the fish were treated with a veterinary medicine which protected them from sea lice for the first six weeks at sea whilst the other half were not.
The numbers of salmon from each batch of fish that returned to the rivers were noted and counted then the batches were compared to see if the protected fish did better than the others. The results were very interesting. There was a difference, but it was very small. On average across all the experiments it amounted to just 1%. In other words of every 100 fish leaving our rivers just one does not return because of sea lice. The other 94 that do not return are lost at sea for other reasons. An almost identical series of experiments carried out in Norway at around the same time came up with very similar findings also both experimental groups whether treated or not had a similar overall rate of loss to wild fish from the rivers showing they too were experiencing the same conditions. Interestingly the results were the same whether the rivers used to carry out the experiments had salmon farms at their mouths or not. Even when those farms reported a high incidence of lice, the results were the same indicating that there was no connection between the salmon farms and the survival patterns of smolts at sea. These two large scale independent studies clearly tell us that the reduction in the number off salmon returning to our rivers over the last thirty years is not due to sea lice and therefore can have little to do with salmon farming activity.
Based on this work, the Marine Institute of Ireland have been able to conclude that ‘sea lice are a minor and irregular component of the mortality of wild salmon at sea.’ They have also stated that the effect of sea lice is unlikely to be a significant factor influencing the conservation status of salmon stocks.
Not everybody agrees with this analysis. Another group of scientists analysed the Marine Institutes data using a different type of statistical analysis and reached the conclusion that the Marine Institute group had marginally underestimated the effect of sea lice. They calculated that it was closer to 2%. The important point is that whether it is 1% or 2%, it still remains a minor component of overall marine mortality. However, these scientists went a step further and tried to transfer this 2% over to make a comparison with the very small number of fish actually returning to the rivers. They reasoned that if the influence of sea lice was somehow eliminated then instead of 4 fish returning to the river, six would come back. They then suggested that this represented a 30% influence on salmon survival attributable to sea lice. This has caused a lot of confusion. The argument has been presented simplistically in the media with the Marine Institute saying sea lice cause 1% mortality and the other group saying that sea lice actually cause 30% mortality. People don’t know who to believe. In fact, if one compares like with like, both groups hardly differ at all. Both groups agree that the influence is small but by applying the effect to very low numbers of fish returning one group have grossly exaggerated their position.
It is not a valid scientific comparison to transfer the small influence caused by the sea lice on salmon going out to sea and then apply this to the very small numbers returning. Plainly we must now look elsewhere for the explanation for the steep decline in our salmon stocks. We do not know the exact answers to the question but it is clear that the focus of scientific research must now look beyond salmon farming if the cause of this mystery is to be uncovered and the trend of decreased salmon survival is to be reversed. The time has come to move beyond argument and find out what is really devastating our treasured wild salmon. “
The CSA says that the SEPA Framework is scientifically defensible, but based on the science he has presented, I would suggest that it is not