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reLAKSation no 1088

SEPA response: My commentary entitled ‘Sloppy Science’ was written prior to the publication of the SEPA consultation response later this week. The document is over sixty pages long and is accompanied by over sixty responses and clearly will take some time to review for further comment.

However, the published overview caught my attention and as it is extremely relevant to this week’s other commentaries, I wanted to respond now

The Overview begins:

“Scotland is renowned worldwide for the quality of its rivers, lochs and seas. Despite this, in nearly 60% of salmon rivers across Scotland including on the west coast and Western Isles, salmon populations are in poor conservation status. “

This is simply incorrect, and I detailed why on the first page of my response, but it seems that SEPA have chosen to ignore my explanation because they have repeated the 60% figure in their overview.

I am not surprised because the 60% figure (now 65%) comes from Marine Scotland Science and naturally in my opinion, SEPA will prefer to believe MSS’s data than mine. After all, MSS have worked closely with MSS to develop this risk-based framework. It is their science.

The consultation response does refer to challenges to the underpinning science (let alone my challenge to the simplistic maths) but the reality is that the science is irrelevant as SEPA have made it clear that the reason they are progressing this risk-based framework is because the Minister has told them to do so.

Of course, the only reason the Minister has made such a proposal is because of the advice given by Marine Scotland Science, as detailed in their summary of the science (although I have been informed the summary of science has not informed Government policy, but there is no clarification of what science does).

We do know wild salmon stocks are significantly threatened yet the only remedial measure of note is catch and release, which is yet unproven at stopping any declines. We also know that salmon farming is not to blame.

The reality is that neither 60% nor 65% of Scottish salmon populations are in poor conservation status as claimed by MSS because these are percentages of arbitrary numbers. The river gradings based on actual salmon habitat actually tell a very different story. The problem is these gradings have little to do with salmon conservation and more to do keeping the angling sector happy. At the same time, the summary of the science relating to sea lice is extremely selective, which is why SEPA’s consultation response summarises the response from the farming sector as: not believe that there is any sound scientific evidence behind this proposal, which appears to be based on pure conjecture..

I would be more than happy to discuss these issues with MMS, but they are extremely reluctant to do so. I only know that if anyone would challenge my view of the science, I would be more than willing to stand up and defend myself. I fail to understand why there cannot be a full and frank discussion about the science between MSS and the industry before SEPA continue their pointless journey to curtail a sector that is so important to the Scottish economy. Surely, if MSS are so confident that their science is correct, then their scientists should have no difficulty in explaining why to a bunch of salmon farming folk.


Sloppy science: Following on from my comments about the proposed river gradings for 2023 in the last issue of reLAKSation, Marine Scotland have stated on the Scottish Government website that:

‘in the proposed river gradings for the 2023 season 113 out of 173 stocks have been assessed to be in poor conservation status’ (

Yet, it is not this statement which is of concern. It is the fact that the statement is followed by the figure (65%). Mathematically, this is correct, but in terms of determining the conservation status of salmon rivers in Scotland it is extremely misleading. I would even argue that this is an example of sloppy science. It is all to easy to say that 65% out of 173 salmon stocks in Scotland are of poor conservation status without bothering to examine salmon’s true status.

The problem with this ultra-simplification of the status of Scottish salmon stocks is the impression that all 173 stocks are similar, when they are not. The extreme example of this is that one of the stocks is the Lealt River on the Isle of Skye. The area of its’ salmon habitat is 4,200 m2. By comparison, the River Tweed has an area of 16,229,600 m2, which means that the salmon habitat in the Tweed is approximately 3,864 times greater than that of the Lealt River. How can these stocks be realistically compared against each other, when they are classed equally as two of the 173 stocks?

When the river gradings were first launched, the assessment related solely to the existing fishery districts, and whilst these are not of equal size too, they do tend to relate to a whole river system. However, many anglers complained the gradings ascribed to the whole fishery districts did not reflect the conservation status of their specific part of the district. Consequently, Marine Scotland Science expanded the assessments on request to look at different river’s systems within the districts. This means that there are now 173 stocks instead of the original 109, many of which are relatively small.  Surely, any assessment of Scotland’s salmon rivers should cover all 300 plus rivers or just the fishery districts and not some random mixture of the two?

Instead of taking such a simplistic view of stocks, a better comparison would be to use the size of each river, fishery, or district. This information is available as it is already used as part of the assessment process.

According to the Scottish Government interpretation of the data, the percentage of the stocks with the three different grades are as follows:


% of number Grade 1 Grade 2 Grade 3
16.7 17.9 65.3


If the percentage of grades are calculated based on area of salmon habitat, then breakdown would be:


% of area Grade 1 Grade 2 Grade 3
50.9 17.7 31.3


Clearly, this provides a completely different picture of the conservation status of Scottish salmon stocks. The impression is now that instead of two thirds of stocks being of poor conservation status, two thirds are of sufficient status that they can be legally exploited. Surely, this cannot be correct. It is only a short time ago that the Scottish Government had announced that the 2021 rod catch was the lowest on record and back in June, Fisheries Management Scotland called for action to help halt the decline. Yet, the conservation status of stocks based on area would suggest that such concerns might be somewhat premature. It’s therefore not surprising that exploitation of angling by rod and line continues regardless.

Before I consider the discrepancy between these different methods of assessment, I would like to mention the gradings relating to the west coast. In terms of total area of salmon habitat as expressed in square metres, the west coast represents 23% of all of Scotland, yet, in terms of the number of areas, the percentage is 54%. Clearly, using number of stocks, the west coast receives a disproportionate amount of attention. Perhaps, this is why SEPA has been charged with launching a risk-based framework to help protect wild salmon from salmon farming. However, the reality is just 8.7% of Grade 3 stocks, based on the total area of salmon habitat, are located in the west coast Aquaculture Zone.  It would seem that the planned SEPA measures are akin to using a sledgehammer to crack a nut.

When just the Grade 3 stocks are considered on their own, then 28% of all Grade 3 stocks are found in the west coast, whilst 72% are located elsewhere. If the SEPA framework is being introduced to help stocks of poor conservation status along the west coast, then what equivalent measures are to be used to protect equally vulnerable stocks elsewhere, especially as there is a much greater spread outside the Aquaculture Zone? It seems that the only measure is voluntary catch and release.

The lack of any alternative solution is explained in the review of salmon stock status published alongside the new gradings. This states that the declines in spawning stock (producing the eggs on which rivers are assessed) show no signs of ceasing and there is concern over the limited management actions available to counteract the continuing declines in the number of spawners. Perhaps the availability of limited actions may be because nothing was done when there was more opportunity to do so.

The reason why spawners are in decline now is because since 1971, when numbers were first recorded, the number of fish returning to Scottish waters (and elsewhere) have also been in decline. It is suspected that this decline is being driven by changes in oceanic conditions, but any evidence is rather sparce. There has been very little research about salmon at sea which is why we don’t know what is happening now. The problem is that the wild fish sector has always claimed that they should focus on the things they can change rather than things they can’t, and of course this means salmon farming. However, problems at sea can never be changed (or adapted to) if the reasons for the problems are not known.

The main mitigation has been a reduction in exploitation or a change to catch and release, which as mentioned in previous issues of reLAKSation using the example of the River Dee, does not appear to be a solution. Up to 2010, there was little real concern because the reduced exploitation meant that the number of spawners increased. It is only in the last ten years, that the impact of these long-term changes has been manifested. Both returning fish and spawners (effectively the same fish) have declined. The concern should be that it is now just too late to do anything.

Perhaps, many years ago, NASCO should have been commissioning and coordinating international research from their membership to investigate what has been going wrong for salmon out at sea. We are now paying the price for such failure. Meanwhile, NASCO have this year commissioned a new review of salmon farming on wild fish. It’s not surprising that wild salmon remain under threat, when clearly salmon farming isn’t the reason why wild fish are in decline.


Action: The Daily Record reports that a new group has been formed to help protect salmon in a Perthshire river said to be in crisis. They intend to push for urgent action from the Scottish Government by lobbying Government agencies and ministers to act on its Wild Salmo Strategy which was unveiled earlier this year.

The new Ericht Focus Group is backed by the Tay Salmon Fisheries Board after one of its members outlined the multiple threats facing salmon swimming in the river. The group says that the crisis facing Ericht salmon is all man-made. There is nothing natural about it. They add that this is not just about the local water channels, water abstractions or a couple of decrepit weirs but rather what man has done and is doing to a barometer species, a special area of conservation, to income, to jobs, to Scottish tourism, hospitality, biodiversity, and the natural environment.

And I thought it was all about protecting the salmon. Perhaps a clue to the intentions of the group is that the driver of this group is Jerry Saunders, the angling representative on the Tay Salmon Fishery Board and the group consists of members of the Board and the Blairgowrie and Rattray District Angling Association (BRDAA). Of course, one of the man-made impacts on the river that is not mentioned is the impact of angling. As usual it is everyone else’s fault. Mr Saunders especially highlights the amount of water abstracted from the river during low flows, which he says is more than is responsible and acceptable to protect the River Ericht’s valuable ecology. That is the same valuable ecology that the BRDAA target for their sport.

News of the formation of this group comes at the same time that the Tay Salmon Fishery Board have announced their river management plan for 2022 -2024 (, the introduction of which states:

“The Board itself cannot do much to influence what happens at sea, where salmon do have problems currently, therefore, must do all it can to help the salmon when they are in our care in our rivers.”

The statement puts into words the fundamental problem with the wild fish sector. The real issue with wild salmon is what happens at sea and because over many years any attempt to understand what is happening to wild salmon at sea has simply been dismissed as being outside their capability and thus nothing has ever been done, including exploring the opportunities for both national and international collaborative research. Instead, the focus is always blinkered towards local matters and reading through the list, they are all exactly that and unlikely to do anything towards reversing the continued decline of migratory wild fish.

The River Ericht is mentioned four times in the wider Tay river management plan. Three relate to smolt passage, but these are mentioned as part of the 2022 projects already underway. The first of these is that the weir and fish pass under the road bridge in Blairgowrie is disintegrating and there could be potential for salmon being obstructed if the pass becomes blocked. The second and third relate to a fish farm in Blairgowrie (inevitably) that abstracts from the river and despite a recent SEPA review, there are still concerns. This is a small flow through farm producing trout for restocking i.e. for angling.

The final mention is the only one about the river Ericht for projects to be started in 2023 or 2024. This is about the spread of invasive non-native species, and this covers a number of rivers including the Ericht. The concern relates to American signal crayfish, although the Board says that their impact on salmon is uncertain.

Clearly, the Tay Fishery Salmon Board’s concerns about the Ericht are not as great as those of the local angling association.

Other areas to be addressed in the coming years are habitat improvement, predation and smolt passage. Finally, the Board want to build an evidence base through coordinated scientific research and monitoring about the health of the river.

And yet, wild salmon are supposed to be in crisis. There appears to be no urgency in this plan and why should it be after all, this is a Grade One river with an 87.08% chance of meeting its conservation requirement.

What is less well advertised is that the River Earn, one of the Tay’s tributaries is classified as Grade Three with only a 46% chance of meeting its conservation status. The River Eden, another tributary is also Grade Three but has only a 20.23% chance of attaining its requirements. Could it be that the status of the main river has masked the real problems elsewhere. Perhaps the time has come to follow the lead set by Norway and Ireland and close all these Grade Three rivers to any form of exploitation. As highlighted previously, this would only cover around 30% of Scotland’s salmon habitat and not 65% as claimed by the Scottish Government.