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reLAKSation no 1111

SPILLS: The SPILLS report was due to be published this week but as the Cabinet Secretary was unwell the publication was delayed. I certainly wish the Cabinet Secretary a speedy return to full health. I’m not quite sure why the Minister needs to launch this publication except possibly in an attempt to give it more credibility than it might otherwise deserve. As readers of reLAKSation are already aware, my analyses of the available data would suggest that the sea lice dispersal models have not been validated by this project.


John & Rachel: John Aitchison of Coastal Communities Network and Rachel Mulrenan of Wild Fish have become unlikely bed fellows in joining together to write an opinion piece for the Press & Journal in which they accuse the salmon industry of greenwashing because of their wild fish support fund.

This is not surprising because in their eyes nothing the salmon farming sector can do, will satisfy their demands to completely remove salmon production from Scottish waters.

The written word is one thing, but it is more interesting to hear their views in the spoken word and their piece in the P&J appeared at around the same time that they both appeared on different podcasts. As Rachel has recently taken over as Director of Wild Fish Conservation Scotland, her podcast was the most enlightening and certainly worth listening too.

Rachel was interviewed by Ireland on the Fly, the presenters of which said that Rachel was to provide a more fact-backed and scientific view of salmon farming. She was first asked about the background to the arrival of fish farms in Scotland.

‘Salmon farming arrived in Scotland towards the end of the 1970s. It was initially a small cottage industry of small companies like netting companies that had previously engaged in catching wild salmon. The first farms were small of 50-100 tonnes and that is in contrast to farms of 1500 tonnes today. By the 80s and 90s, the small farms were consolidated into the Norwegian, Faeroes and Canadian companies, that have expanded into the large open net farms that we see today.’

My memory of the time differs from Rachel’s facts.  The first salmon smolts were put to sea in 1967 by staff of a very small cottage business named ‘Unilever’, an Anglo Dutch corporation with interests around the world. They eventually named their salmon farming operation – Marine Harvest. The company has dominated salmon production in Scotland ever since.

The first farms were much smaller than 50 tonnes. By 1982, total Scottish production had only reached a thousand tonnes and the years that followed were something of a Klondike era as new farmers saw the opportunities arising from Mrs Thatcher’s boom years. Those benefiting from the boom times wanted all the trappings of luxury and that included salmon for which they were willing to pay high prices.

In 1985 the make-up of farms was:

By the early 1990s, Mrs Thatcher’s boom years were over and as production had risen, the high price attained could not be sustained. Many of the Klondike type companies found that lower prices were not as profitable and wanted out. Some of the most willing buyers were from overseas. However, the period of consolidation lasted much longer than Rachel suggests. It was as late as 2014, when Canadian interests arrived in Scotland and much more recently for those from the Faeroe Islands.

Rachel then suggested that those in power chose to sacrifice the west coast to salmon farming because they knew of the damage salmon farms would cause. She got asked:

Question – Why are fish farms all based on the west coast?

Answer: There are a couple of different potential explanations for that. In terms of a non-conspiracy theory perspective than in terms of geography there are sheltered sea lochs that are ideal conditions for salmon farms. Interestingly, these locations are set up in isolated west coast communities and away from the consolidation of power and wealth in Scotland which is on the east coast. You also have really important salmon rivers on the east coast which begs the question if that was a decision made by the Scottish Government to protect those salmon rivers then that’s implying that they acknowledged way back when the industry started that there would be a negative impact on wild salmon from salmon farms so it’s definitely an interesting question?

Question – do you feel that was policy about where they were located?

Answer: I couldn’t really comment on that. I think it’s definitely interesting. I would say that the Scottish Government has not built up that evidence base in terms of the impact of farmed salmon on wild salmon. It does seem from a geographic perspective that the west coast makes sense but then it also does mean that the industry is consolidated in an area that is hard to reach and it’s hard to monitor and it’s hard to see what is going on so yours is a valid question.

This is certainly a very different perspective. This suggests that the authorities knew that sea lice might be an issue. However, I suspect that salmon farming was such a new concept that even the industry could not have forecasted that sea lice would be an issue for farmed salmon. The same person who put the first smolts to sea in 1967 also said that sea lice were never an issue for their salmon before 1984. By coincidence, this was when the 3 mile fishing limit was removed which led to the loss of larval marine fish which might have consumed sea lice larvae in the waters immediately surrounding farms.

The reality was that in the 1960s there was no industry infrastructure. There were no companies selling salmon pens, so these were almost hand built and as such required the protection of sheltered sea lochs. There was no conspiracy just a desire to explore the possibilities of farming the seas.

Rachel’s new collaborator, John Aitchison of Coast Communities Network has been interviewed on the podcast Tommy Outdoors.

He begins by saying that people feel quite strongly about salmon farming on both sides of the divide and there doesn’t seem to be much middle ground partly because there is no forum to talk about it or very little opportunity to talk about it between the two sides.

I found this an interesting comment because I offered to discuss sea lice with the CCN’s Aquaculture Group but my offer was immediately rejected. CCN’s Aquaculture Group later wrote a letter to the West Highland Free Press saying that it is time that the industry (and me) accepted the truth that sea lice from salmon farms are a risk to wild fish. Rather than have a tit-for tat exchange in the paper’s letters page, I wrote to CCN. I don’t normally publish private correspondence, but their response should be read.

“Please let me explain a bit.  The truth I am talking about is not whether lice from fish farms pose a threat to wild salmon.  It is about your misrepresentation of SEPA’s opinion.  You and the unnamed representative of the industry said that SEPA agree that lice from farms do not pose  a threat to wild fish.  SEPA do not agree.  I have provided evidence for that.  What I said is true, what you said is not.  I will not stand by and let senior officials be misrepresented in the interests of the salmon farming industry.

I do not wish to discuss your evidence either way.  You are entitled to believe whatever you want. I don’t mind.  I only care what the people in positions of responsibility for regulation think.  That debate seems to be well and truly over.

Put simply, there are a great many reasons why salmon farming needs to undergo radical change and stronger policing.   Sea lice are just one of them.  We work to ensure that regulation is suitably strict.  ADDs were another, but we have won that one.  We move on to tackle other issues like pollution, medicines, fish welfare, mortalities.  We don’t have anything to gain by debating with you, so we don’t.

Yours etc”

(I should just mention that my representation of SEPA’s opinion is recorded in the official record of the Scottish Parliament Rural Economy Committee from November 2020 and is available for all to see).

In answer to John’s comment, this is not about whether there is a forum or not but whether there is a willingness or a desire to actually discuss the issues, except to those who already agree with you.

John was asked that as a wildlife cameraman, what was the moment that made him get involved in campaigning against salmon farming. He said that he has lived locally (Argyll) for about thirty years and initially he thought that fish farms were a good idea as it was better than catching wild fish. John stopped eating wild fish and ate farmed salmon instead. However, he only started to look deeper into salmon farming when a new site was proposed near a salmon river near where he lives. The local community were very clear that they didn’t want it for multiple reasons, so he got involved in a local campaign and his group is now part of the Coastal Communities Network.

It is interesting that John was happy with salmon farming until a planning application was made for a farm on his doorstep.

As with Rachel’s interview, it is worth listening to all John’s views on salmon farming to understand his perspective.

What is clear from both these podcasts, is that Rachel and John would be better served by talking to the salmon farming industry. All that happens now is the same misinformation goes round in circles because of an unwillingness to actually listen to the other side of the divide.


Second year: During a recent SEPA risk framework workshop, the following graphic was shared. This is the result of running the proposed sea lice dispersal model that will be the basis of the framework. SEPA ran the model using 28,534 virtual smolts and found that in 2021 85% of the fish were under the proposed lice threshold whilst the following year, it was all the fish. This confirms my own work which indicates only a minimal risk to migrating smolts from sea lice from salmon farms.

I would not normally discuss the content of such meetings, or the people involved but in this case it is relevant to this commentary. Dr Alan Wells asked the question whether 2021 was during the second year of the farm production cycle.  This is because it is assumed that the production of larval lice is much greater in the second year of a salmon farm’s cycle simply because the fish are larger.

The Lochaber Fisheries Trust have had a graphic posted on their website for as long as I can remember.

This plots prevalence (the percentage of fish in the sample infected by lice) and abundance (the average number of lice per fish within the sample) and although there is some variation, there does appear to be a clear pattern of higher prevalence and abundance in alternating years.

In 2010, the Marine Scotland Science published a paper in Biology Letters looking at sea lice levels on sea trout in relation to fish farm production cycles. The paper, Middlemas et al (2010), found that lice levels were higher in the second year of production in Loch Shieldaig, although they did not represent this graphically. Their data is presented in the following graph, which only considered abundance.

The paper also looked at nine sites over one production cycle from 2002 to 2003. Eight of these showed a higher level of lice in the second year, whilst one did not, with higher lice in the first year.

With the publication of the sea lice counts from 1997 to 2019 as recorded by the various fisheries trusts, now under the management of Fisheries Management Scotland, there is now an opportunity to examine this pattern of cycling over a longer period of time.

I have taken the data from the 12 sites with the longest continuous runs of data and plotted them following the example of Lochaber Fisheries Trust in calculating both prevalence and abundance and not just abundance as did MSS.

The following graphs show the findings – The blue line is prevalence, and the orange bar is abundance:

Whilst there are glimpses of the evidence seen by MSS and Lochaber Fisheries Trust, there are clearly long runs where there is no clear pattern at all.

These graphs highlight one major issue with sea lice sampling and that relates to sample size. Small samples are unlikely to be representative of the true level of infestation, especially when it comes to prevalence. In this data set, the smallest sample was just eleven fish.

I would suggest that these graphs show that we need to be more wary about claiming that just because a farm is in the second year of production, that sea lice are at any greater risk. It’s equally worth remembering that the risk, as shown by SEPA from their simulated smolt runs, is extremely low and that the claims made by industry critics are extremely overstated.