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reLAKSation no 1127

Priorities: Fish Farming Expert have reported that the Scottish Environment Protection Agency (SEPA) has announced its priorities for 2023-2024. This includes “supporting sustainable aquaculture by implementing the new sea lice risk assessment framework with Scottish Government, abstractors and others.”

The purpose of SEPA’s priority is to protect wild salmon and sea trout from sea lice and whilst SEPA acknowledge that wild fish are at crisis point, they appear not to want to consider addressing the issue of dumped sewage into Scottish rivers as a priority. Earlier this year, the Daily Record reported that sewage was dumped in Scottish rivers more than 14,000 times in 2022 which equates to nearly 40 incidents every day.  Wild salmon campaigner Feargal Sharkey said that these figures laid bare the ‘full scale of horror and abuse of Scotland’s rivers’ especially as most of the sewage outflows are not even monitored. Is this because monitoring sewage is not a priority? Or is it because SEPA are too busy trying to impose an unnecessary and pointless framework on the salmon farming industry to bother looking at the real threats to wild fish. In my opinion, SEPA have got their priorities wrong.


Consultation: Welcome to SEPA Model Land. I recently wrote about a new book ‘Escape from Model Land’ and after looking through SEPA’s latest consultation about the sea lice risk framework, I can only conclude that SEPA are firmly stuck in Model Land with little grasp of the reality of sea lice science. Sadly, SEPA have made it clear that they are pursing this framework because the Minister told them to do so regardless of what the science or the facts actually say. I suspect that this latest consultation will be just a paper exercise so SEPA can say that they have gone through the process rather than actually considering the submissions.

This consultation is just the latest part of the crusade by MSS and now SEPA against the salmon farming industry. It is now widely acknowledged that wild salmon and sea trout are in crisis, although the will to address the issue is very mixed. Some years ago, Marine Scotland produced a list of pressures affecting wild salmon and consequently, they established a first working group to address one of these pressures – salmon farming. Yet subsequently no other working group was formed to address any of the other pressures. SEPA have been tasked to launch a sea lice risk framework to help protect wild salmon, yet there has been no attempt to launch any other initiative to protect these fish. In fact, it could be argued that there has been no change at all. The Wild Salmon Strategy, long in discussion, is still far from any progression. Meanwhile, another consultation to discuss making catch and release mandatory was rejected by anglers and thus despite salmon being in crisis, anglers continue to catch and kill the fish for sport.  This would have been a simple change that would have saved 2,966 wild fish from a premature end at the hands of the angling fraternity.

The big question arising from the proposed sea lice risk framework is how much of a risk are sea lice to wild fish? Even though Marine Scotland Science are coming to the end of a £3,689,599 project about sea lice, they are still unable to answer the question as to how many wild fish are supposedly dying from sea lice from salmon farms. If the number was shown to be no more than 2,966, then surely no risk framework should be necessary as clearly Marine Scotland consider this loss to be acceptable, otherwise, surely, they would have introduced mandatory catch and release.

Equally, SEPA appear to suggest that if sea lice levels on farm rise, then measures would be necessary to protect wild fish. In that scenario, if sea lice numbers on a farm were to rise by an order of one, how many more wild salmon would be expected to die from sea lice infestation and how many if the number rose by two and so on. It just seems that this framework is being imposed on the industry because there is a perception that sea lice from salmon farms are responsible for the decline of wild fish numbers. I probably don’t need to remind readers, that Peter Pollard, head of ecology at SEPA told the Scottish Parliament’s REC Committee that sea lice from salmon farms were not responsible for declines of wild fish. As part of the launch of this consultation, Peter Pollard has said that tighter lice control would benefit wild fish and the reputation of the industry. I look forward to hearing exactly how tighter controls would benefit wild fish. They certainly won’t help the reputation of the industry. Tighter controls would mean increased treatments and consequently higher mortality as a result of stress from increased treatments. Already those opposed to salmon farming have said that the framework doesn’t go far enough but then such critics are opposed to any salmon farming in Scotland.

As mentioned, SEPA aren’t really interested in the science, and they leave this to their partners at Marine Scotland Science.  Their document on sea lice impacts states that ‘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.’ However, as already highlighted, they make no attempt to quantify what this means.

More recently, they have suggested, without any attempt to qualify their claim, that mortality due to sea lice is 20%. It seems that this number is derived from two scientific papers one of which suggests mortality is 1% and the other 39% (1+39/2 = 20). The first figure comes from an Irish paper based on a long-term experimental project. The other comes from a group who claimed that the Irish work was wrong, and their interpretation of the data was a mortality level of 39%. The Irish Marine Institute explain that both sets of numbers show the same impact and that sea lice have a minimal impact on wild fish populations ( so I won’t repeat this here.

If 20% of wild salmon are dying around the salmon farming area as a result of sea lice, then Marine Scotland Science should be able to show that this is the case. They have over seventy years of catch data from all the rivers around salmon farms and should be able to link changes in salmon numbers due to the arrival of the local salmon farm.

The following graph shows that salmon catches actually increased after the arrival of the salmon farm in Loch Ewe. This is the same farm that anglers blame for the decline of Loch Maree sea trout.

Perhaps, Marine Scotland Science should have used some of the £3.6 million funding to investigate actual wild fish stocks rather than rely on the views from academic papers. The problem is that real data would undermine their established narrative.


What they don’t tell you 3: Wild fish are reportedly in crisis yet there has been no discussion or publicity about the 2022 Scottish catch statistics. This might be because the wild sector doesn’t want to draw attention to the fact that they continue to kill fish for sport, but more likely that they wish to avoid public scrutiny of the past discrepancies between the numbers presented by Fisheries Management Scotland and the official Scottish Government statistics despite both sets of data coming from the same sources. It does make one wonder about the other claims made about the marine environment if the numbers of fish caught cannot be counted accurately.

Anyway, I would like to continue my own examination of the data with a look at sea trout. One of the claims made by the wild fish sector is that wild fish stocks will recover if salmon farming is removed from Scottish waters. At the time, I argued that the removal of the salmon farm in Loch Ewe presented a unique opportunity to study any changes to the local environment. Unfortunately, my suggestion was not taken up and so I must rely on some basic catch statistics to draw any conclusions.

The following graph is the sea trout and finnock catches (finnock (young sea trout) were only recorded from 2004). This is taken from the latest 2022 catch statistics.

What is clear is that following the removal of the farm in November 2020, there has been no dramatic recovery in sea trout catches from Loch Maree. This is not unexpected because whilst the collapse of the Loch Maree sea trout fishery has been attributed by the wild fish sector to sea lice from salmon farming, they have yet to provide any evidence to support their claim.

The ‘scientific’ support for the claim against salmon farming comes from the 2006 Butler and Walker paper but the official catch data from the Loch Ewe system differs significantly from the Loch Maree Hotel data used in the paper.

The official statistics show that the immediate drop of catches simply didn’t happen as Butler and Walker claimed. Like most of the wild fish lobby at the time, they were too quick to blame salmon farming rather than consider any other explanation. For example, they did not look at the impact of the removal of the three- mile limit in 1984 on sea trout stocks. As I have shown previously, the collapse of sea trout closely mirrors that of other marine species.


Sea trout catches are represented by the solid line. Other species include cod, saithe and whiting. Interestingly, no-one has shown any interest in this relationship, even those campaigning for a return of the three-mile limit. I suspect that it is because the relationship has been identified by someone who is part of the salmon farming industry and there is a general reluctance to be seen to be collaborating with anyone working in aquaculture because the salmon farming sector is portrayed as having a negative impact on the environment, even when it is not.

Of course, the other reason why Loch Maree sea trout have not recovered is because sea trout across the west coast have been in decline for many years, even well before the arrival of salmon farming. I have presented the following graph many times previously asking for anyone to explain how salmon farming is perceived to be the cause of sea trout declines when the fish were in decline for at least thirty years prior to the arrival of salmon farming to the area. I am still waiting for an answer.

What everyone seems to ignore is that sea trout are in decline across all of Scotland. The graph produced by the Scottish Government to illustrate changes to sea trout catches clearly illustrates the problem.

Those providing the catch statistics offer no explanation for why sea trout are in decline. They simply point out that the 2022 catch is the fourth lowest on record. Equally, the statistics do not differentiate between west coast declines, which are blamed on salmon farming and those from the east coast where there are no salmon farms.

The graph of east coast declines is remarkably similar to the total Scottish catch which shows that east coast catches make up the majority of sea trout catches in Scotland. Rather surprisingly, I don’t hear any calls to help protect east coast sea trout but then there are no salmon farms to blame.

Back in 2016, Marine Scotland Science published a report that suggested the declines on the east and west coast may be for totally different reasons meaning that west coast declines must be due to salmon farming. However, no attempt was made to suggest any reason why east coast sea trout catches are in decline. It doesn’t seem to occur to any fishery manager or biologist that perhaps, sea trout may be in decline across Scotland for exactly the same reason; one that no-one can yet explain. The possibility that sea trout are in decline everywhere for the same reason has never been considered because salmon farming can not then be clamed for impacting wild fish.