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reLAKSation no 1177

Trout too: In the last issue of reLAKSation I examined the salmon & sea trout catch statistics and pointed out amongst other things that the decline in the salmon catch from Scottish rivers outside the west coast Aquaculture Zone matched that of catches from rivers within the salmon farming area. From this, it can be concluded that the decline in salmon numbers is similar across all of Scotland and that the claimed impact on wild salmon numbers from salmon farming is simply not reflected in the catch data.

I have now carried out a similar analysis of sea trout numbers and if anything, the decline of sea trout catches is slightly less in the salmon farming zone than elsewhere.

However, there is no doubt that overall, the declines of sea trout catches are very similar between fish caught from within and outside the Aquaculture Zone.

I have tracked sea trout catches for the whole time series from 1952 and continue to do so. However, the then Marine Scotland Science began including finnock (very small sea trout) alongside the sea trout data from 2004. I have not added these together in my main analysis because it clearly will affect the long-term data series. However, I do not believe that combining sea trout and finnock catches together is a problem when examining shorter term data for example from 2011 which is seven years after finnock were first recorded.

When combined sea trout and finnock catches are plotted, the decline of catches from within the Aquaculture Zone and elsewhere in Scotland is parallel.

The question for Scottish Government scientists, SEPA and the wild fish sector is if sea lice from salmon farms are killing sea trout, then how can the catches show almost identical rates of decline? I won’t be holding my breath waiting for an answer,


NASCO: Its nearly 14 years since I had my first (and last) encounter with someone from the North Atlantic Salmon Conservation Organisation (NASCO). This was the Aquaculture Debate meeting that took place in Fishmongers Hall in October 2010. I had been asked to be involved as a favour as no-one else was interested in participating, probably because they didn’t want the grief. The agenda was that someone from the aquaculture industry (me) would debate the impacts with a representative of the wild fish sector and that was Dr Malcolm Windsor of NASCO. It was this meeting that started me off on my journey to investigate sea lice.

Since that meeting, I have made several requests to meet with their General Secretary and all have been rebuffed for some reason or other. I have offered to speak at their general meeting but again my offers have been rebuffed. I don’t bother asking anymore.

NASCO was established in 1984 under the Convention for the Conservation of Salmon in the North Atlantic Ocean. The objective of NASCO is to contribute, through international consultation and cooperation, to the conservation, restoration, enhancement, and rational management of salmon in the North Atlantic Ocean. The publication of the latest Scottish salmon catch data, which I discussed in the last issue of reLAKSation, and which is the worst on record, would suggest that NASCO have not been very good at reaching their objectives. To me, this is not surprising since NASCO is dominated by angling interests and as anglers maintain that the poor state of wild fish stocks is everyone else’s fault, but their own, wild salmon’s future will remain bleak.

In common with all the wild fish organisations, NASCO have a very negative view on salmon farming. In 2021, it agreed to fund a study of the latest scientific knowledge on the impacts of sea lice and escaped farmed salmon with a combined budget of €83,000. Why they need to spend this amount of money on this research is a mystery because the outcome is a forgone conclusion. Despite claims that the approach will be structured in a rigorous and transparent way, most of those taking part have published scientific works implicating salmon farming in the decline of wild salmon despite a lack of any hard evidence to support their claims. In addition, and from my perspective, none of them have been willing to discuss the science.

NASCO have just published an update on the current position of this review (May 2024 CNL (24) 12) and the section on sea lice is apparently progressing well. A protocol was developed entitled ‘Impacts of sea lice from aquaculture on wild Atlantic salmon: – Does exposure to sea lice from aquaculture have a population-reducing effect on Wild Atlantic salmon’ and this protocol achieved the following results:

A total of 2784 papers and documents were screened with 1931 been deemed as relevant. A further 293 papers were drawn from the grey literature with another 560 from other searches.

In total 17 papers included primary data of which 10 had data worthy of extraction

Just seven papers included observational studies with four using control-impact multisite with or without aquaculture: one with ‘before and after’ and two with time series studies.

Clearly, NASCO have not shared details of which papers have been identified but it is noteworthy that just 17 papers out of 1931 contained data worth considering.

It is also interesting that the ‘expert’ group have recruited four sea lice “experts” to participate in the review process. Two are from Norway, one from Ireland and the other from Scotland. The sea lice “expert” from Scotland works for the Marine Directorate, whose scientists have been unwilling to engage in any discussion about sea lice, seemingly unless it is to confirm that sea lice have a negative impact on wild fish. All these scientists are happy to be involved in the NASCO process but are not willing to engage in any discussion that might highlight the possibility that their prospective findings may be totally wrong.


Old Found Narrative: According to the Canadian Press, a new study says that aquaculture is likely driving wild salmon extinction in Newfoundland. The first thing that jumps out of this work for me is that one of the authors is also a member of NASCO’s expert group. If he believes that aquaculture is driving wild salmon towards extinction in his home locality, then he is unlikely to think differently about salmon farming elsewhere. This is why the NASCO review is a pointless waste of time.

This latest paper considers a wide range of factors that could be implicated in wild salmon’s decline, but the authors select aquaculture as the prime suspect based not on any hard evidence but simply on a review of selected papers, the first of which is a paper based on the annual report from the Norwegian scientific committee on wild salmon management. I have personally challenged the accuracy of the committee’s findings every time they publish a new annual report but none of the committee members is keen to stand up and tell me that I am wrong. I suspect they assume that the power of collective research institutions outweighs a lone voice, irrespective of whether the science is right or wrong.

However, the paper focuses more on escapes than sea lice. The suggestion is that interbreeding weakens the fish and leads to increased mortality. However, the authors ignore an important point. In their discussion, they say that ultimately, the greatest impact on wild salmon will be in rivers with small or depressed populations. What they don’t say is why these populations are now small or depressed. It is the same story in Scotland where a sea lice risk framework is being imposed to protect wild salmon stocks, only because wild salmon stocks are now so low. No effort has been made to address why these stocks are low in the first place – and it isn’t salmon farming.

According to Fish Farming Expert, two of the paper’s authors, including the one involved with NASCO, made speculative statements to the media regarding their view of why salmon have declined in the Connie river. In response, the Atlantic Canada Fish Farming Association has called for a retraction of their statements arguing their claims are unfounded. The ACFFA says that:

  1. Wild Atlantic salmon populations had been in decline long before the advent of salmon farming.
  2. Very few farmed salmon have been detected in the Connie river which is located 15-20 km from the nearest salmon farm.
  3. The salmon farming industry adheres to strict containment protocols with escape rates at less than 1% since 1995.
  4. Sea lice are not a significant issue due to low salinity levels in the locality.
  5. Federal and provincial reviews over the last twenty years have concluded that salmon farming has minimal impact on wild salmonids.

I would hope that the ACFFA might demand that that scientists justify their claims face to face with the industry. For far too long, such scientists have made unjustified claims about salmon farming yet remained hidden away avoiding any challenge. If they are convinced that salmon farming is to blame, they should be willing to stand up and defend their claims in public.

Finally, it is worth mentioning that access to the full paper costs £45. If these scientists want to criticise salmon farming, then they should be willing to pay for open access and allow anyone to see for themselves the weakness of their arguments.


Challenge: Fish Farmer included an interesting article in its latest issue. This was a report of a meeting about preparing aquaculture for climate change. Back in April over seventy people attended a workshop which was a joint initiative between the University of Stirling and NOFIMA, which was held at NOFIMA’s offices in Norway.

I was struck by the report of the meeting that said the schedule encouraged important discussions that inspired new perspectives and thought-provoking comments that brought the presenters, panellists and audience together.

The meeting also stressed the need to bring stakeholders together and the meeting showed how these stakeholders engaged in enthusiastic discussion at every opportunity.

The final panel of the day was how to move forward, and this surprisingly involved the scientist who is the Scottish Marine Directorate’s sea lice expert! Perhaps climate change is a less contentious issue!

I have regularly suggested that a similar meeting should take place focussing on the issue of whether sea lice have an impact on wild salmon population. I fail to understand why there is such a reluctance from the scientific community to want to participate in such an event. After all sea lice have been a controversial issue for much longer than climate change, despite a lack of hard evidence to support the negative narrative against salmon farming. Is the case against salmon farming built on just 17 out of 1931 scientific papers, as identified by NASCO? I suspect that if details of these papers were made public, I could make a case for why some of them might also be discounted.

As I have mentioned, the Scottish industry is now subject to SEPA’s sea lice risk framework, yet SEPA, like the scientific community refuse to consider the science. Instead, they maintain that they must pursue this framework regardless because the Minister told them to.  Given that Scottish Ministers rely on advice from the Marine Directorate’s scientists, it is not surprising that the industry is subject to this ill-conceived and pointless regulation. Perhaps, it’s now time that Scottish Government scientists stand up in the public arena, such as a meeting similar to the one of climate change and justified their narrative.


Outrageous: The June Issue of Fly Fishing and Fly-Tying magazine includes an article claiming that fish farmers have lobbied the Scottish Government over twenty times in the last year in an outrageous attempt to delay or block plans for sea lice control.

I agree with FFFT that it is outrageous that the industry has lobbied the Scottish Government twenty times. They should have lobbied much more because SEPA’s framework is based on flawed science and a lack of any hard evidence. At the same time, the Marine Directorate has succumbed to lobbying by the wild fish sector to maintain angling regulations at their current level despite salmon now being classified as endangered and wild salmon catches being at an all-time low. The SEPA sea lice framework is simply an attempt to deflect attention away from other factors as to why wild salmon are in decline.

Whilst salmon farmers will be subjected to controls to protect every wild fish, last year anglers killed 38 salmon from rivers in and around the salmon farming zone and they were allowed to kill more. By comparison, 2021 salmon were caught and released which rather suggests that there are more salmon on the west coast than the wild fish sector would have anyone believe.

Rachel Mulrenan of Wild Fish (Salmon & Trout Association) told FFFT that her organisation has no links to the Scottish Government implying this of all the wild fish sector which is clearly untrue. Wild Fish have excluded themselves from the wild fish discussions otherwise not the other way round. Otherwise, it is likely they would be lobbying just as hard as everyone else.