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reLAKSation no 1132

Norwegian nightmare: I have had to rewrite this week’s reLAKSation more than once as various news stories emerge from Norway that fuse together into a single narrative.

In a commentary in iLAKS, which I will return to later, it seems that there have been people in Norway who have developed the same thoughts as I have for Scotland. Back in 2016, some aquaculture companies operating out of Vestland got together to take a closer look at the knowledge that exists about wild salmon and sea trout stocks. The conclusion of this review was that the bulk of the knowledge was theoretically based and only a very small amount based on any real evidence. In Scotland, I reached a similar conclusion except that the scale of the actual evidence was miniscule. In Scotland’s case, much wasn’t even theoretical but rather more an illusion of truth.

In Norway, the aquaculture companies decided that in order to adopt the right measures to safeguard wild salmon, it was necessary to gather more factual knowledge about the fish in the wild, so they quietly instigated a project titled Salmon Tracking 2030 that has been running now for 5 years. The work has been continuing in the background without fanfare, so much so that I only heard about it earlier this year.

No Even Søftland of ‘PO3/4 Knowledge Incubator’ has told iLAKS about some of the results from a study of over 50 rivers in Vestland County. The picture that is emerging is that the state of wild fish stocks in most of these rivers are actually doing OK, if not improving. I will return to this later.

Meanwhile, I too have focused on actual evidence of the state of fish stocks in Scottish rivers rather than the theory. My experience is very different to that in Norway. The wild fish sector has not been interested in any evidence that might discredit their narrative that it is salmon farming that has damaged wild stocks, so much so that they have repeatedly tried to discredit me and my evidence. Even after 13 years working on sea lice interactions, I am still portrayed as a hard line activist akin to Don Staniford, even though I have published science to my name. Regular readers will also remember that Marine Scotland Science recently called me Manifestly Unreasonable because I asked for access to catch data from some named rivers.

Interestingly, Marine Scotland has undergone some changes. It is now called the Marine Directorate whilst the areas covered by Marine Scotland Science have been renamed as the portfolio of ‘Science, Evidence, Data and Digital’. Previously, the case against salmon farming in terms of sea lice has been made by the science, even though much has been selective. The document on sea lice posted on the Scottish Government website, which is cited by all critics of salmon farming states: ‘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.’ ` Although this document includes observation data i.e., evidence, they do not support the claimed science. As I have pointed out more than once, Marine Scotland Science have steadfastly refused to discuss this observational evidence with me since at least 2016.

Hopefully, the Marine Directorate will start to put more emphasis on real evidence than theoretical science but I’m not holding my breath.

The latest ‘evidence’ to come out of Norway is from NORCE, the independent research institute that undertakes work for the public and private sectors. They have been engaged to collect data on sea lice by the Norwegian Environment Agency. Their report has been highlighted by Intrafish with researchers saying that the number of lice found on wild fish is alarming.

I would suggest that what is really alarming is the researchers have a poor interpretation of data and the lack of a basic understand of sea lice ecology. Like many in the wild fish sector in Scotland, they have simply jumped to conclusions.

The report focuses on wild fish at Herdla at the far end of the Herdelfjord from 13th to the 24th May this year. The ‘sensational’ results include a sea trout found with 237 lice. This is what they called alarming. In total, the researchers caught 41 sea trout and 8 salmon smolts. The lice counts ranged from 10 lice upwards with an average of 74 lice per fish. Most of the sea trout were damaged with grazed dorsal fins and wounds.

The report concludes:

“Overall, the extraordinary monitoring of sea lice shows a high infestation pressure in the fjords. This is probably a result of relatively high infection pressure from salmon farms in combination with low freshwater run off due to late snowmelt.”

Like much of the ‘evidence’ lodged against salmon farming, the detail tells a very different story. Firstly, the sea trout with 237 lice weighed 743g and cannot be considered some small post smolt sea trout. It was the third largest fish caught. Those lice were not recent invaders.

Much more importantly, the 41-sea trout were caught over eight nettings, so the sample size was not 41 fish at all but ranged from one fish to 18 fish, an average of 5 fish per netting. The fundamental question is whether an average five fish are representative of the population or are all these fish outliers of the population as a whole. I suspect that given the message that NORCE has sent out, they believe that these fish are representative of the whole sea trout population. However, it is clear they are not. These fish do not represent the whole natural population in any way. They represent the few fish that are those with high infestations, whilst the majority of fish will be lice free. Unfortunately, the poor sampling takes the fish that are weaker and are more likely to be caught.

Of course, what is more worrying is that these results have not been questioned by the wider scientific community in Norway. Instead, they have been almost endorsed by them. Fish Focus reports that Ørjan Karslen, head of sea lice monitoring at the Institute of Marine Research said that this time of year is very important as young salmon, often weighing around 20g cannot tolerate getting many lice on them. He added that unfortunately, the number of lice that IMR are seeing this year means that probably very few salmon smolts have made it through the lice belt uninfected.

Interestingly, the NORCE data of eight salmon found only 2 fish around 20g with the others weighing over 100g with the largest 150g. Some of the smaller fish were found with adult lice which could suggest that they might have been infested only when contained in the nets.

Dr Karlsen also said that sea trout are at increased risk because of the numbers of lice that IMR are seeing. However, IMR’s report of recent sea lice monitoring is provided just as a summary. This means that the raw data is missing. So far, a request for access to all the data has been met by silence.

Meanwhile, the Scientific Committee for Salmon Management (VRL) have published their latest report on the status of Atlantic salmon for 2023. They tweeted, ‘This year’s status report for wild salmon is ready. The number of wild salmon returning from the sea was amongst the lowest ever recorded. More and more salmon populations are critically endangered due to salmon lice.’

The status report includes a whole section about sea lice in which they state:

“That sea lice are an influence that has largely contributed to the reduction of several Norwegian salmon stocks is clear from our analyses of which factors have influenced harvestable surplus in the salmon stocks. For the period 2010-2014, we calculated an annual loss of salmon to Norway due to sea lice of 50,000 salmon. Equivalent calculations for later years indicate a loss of 29,000 smolts in 2018 and approximately 39,000 smolts in 2019.”

It is now 2023 and it seems that VRL are still reliant on estimated data from 2010 to 2019, which they repeat ever year. They are so sure that they are right that they no longer bother to even estimate a figure. Equally, they ignore the fact that for every one of these years, anglers have killed over 100,000 adult salmon for sport, but VRL do not consider this harvest to be a threat to wild fish stocks, even though many more fish are lost. They are too focused on sea lice to even see the risk to stocks from such exploitation.

In the 2023 status report they do refer to the latest sea lice monitoring from IMR, which I mentioned above. It appears in a section about the development of stocks in Western Norway. This section states that due to sea lice from salmon farming mortality of wild salmon increased from 2015 onwards based on the results of IMR models. The report also says that production areas severely affected by salmon lice have become larger and the number of stocks infected have increased and in recent years, infestation pressure has been particularly high in the most farming intensive areas in Western Norway. They add that the first results from 2023 indicate continued high infestation pressure in Western Norway.

In their latest report, IMR consider the sea lice situation in each of the Traffic Light zones. Due to VRL’s comments about Western Norway, it is worth looking at the summary data recently published by IMR.  I will look specifically at PO4 because that is where the NORCE team were also active.

IMR provide two sets of data – trawling for salmon smolts and fyke and seine netting for sea trout. What struck me about this data is the lack of consistency. For example, IMR state that the prevalence (percentage of fish in sample with lice) of lice on trawled salmon from Outer Sogn increased over the four weeks studied as did the intensity (number of lice on the fish). However, this is not surprising given that over the first two weeks IMR managed to catch just six fish compared to 401 in the third week. How are these figures even comparable? I also wonder how IMR can calculate the figure of lice per gram when weights are not recorded on the table. As this is a summary, this might be considered unnecessary, yet the tables of sea trout catches in their report, which otherwise is identical to the layout of the trawled data, does include information on weights.

The table of sea trout catches includes those for the Herdlafjord, where NORCE collected their data. Week 19 is recorded as catching just 4 fish. However, as this was when NORCE sampled the fish, they recorded their first netting on 14th of May, which was the last day of week 4. It is hardly representative of the week or the fish. Week 20 they netted on the 15th, 16th, 18th and 20th and the results in the IMR report match those recorded by NORCE. The final week – 21, NORCE netted on the 22nd, 23rd and 24th catching a total of 11 fish. IMR record 18 fish. Did anther team replace NORCE after the 24th which was a Thursday as seven fish seem to have appeared out of nothing.

NORCE record the life stages of the lice they sampled however IMR provide no indication of the life stage. It is actually quite relevant especially with most of the sea trout sampled which cannot be considered post smolt sea trout. As UI have indicated, I have requested the raw data from IMR so I can conduct my own analysis of the two thousand plus fish caught by all methods. It seems that so far IMR are not so willing to share this detail.

Whilst IMR and NORCE are keen to share the news that the lice levels they found are high, the salmon farming sector tells a different story. reports that the industry body, Sjømat Norge, representing both fisheries and aquaculture sectors has said that salmon farming is being blamed for the very large numbers of lice found on seatrout but that doesn’t tally with what is happening to lice numbers in the salmon pens. The numbers of lice in areas PO3 and PO4 have not been as low as they have been if ever. There has been a coordinated attempt to keep lice numbers low in Sognefjord with extensive fallowing and very few fish in the sea. In addition, the production volumes in those two areas have already been reduced under the Traffic Light system by 12% and 6%. The organisation said that if researchers need an explanation for high lice numbers, then they should look elsewhere.

However, it is not just Sjømat Norge who are saying this as the results from Salmon Tracking 2030 shows. The commentary in ILAKs goes into some detail but I will just provide a flavour of the findings here. In all there are eight conclusions:

The first is that whilst the Traffic Light system is intended to manage wild salmon stocks, the rivers in Vestland County are more likely to be home to sea trout than salmon.  This is similar to the experience on the west coast of Scotland where sea trout dominate in some rivers, hence the salmon catch has always been relatively low.

The second conclusion is that there were more salmon present in rivers during the 60s, 70s and 80s and this was more likely due to active restocking programmes at the time. By the 90s new rules meant restocking was phased out and consequently, salmon numbers declined.

At the same time, in the 70s and 80s, drift netting was commonplace, and it is likely that many of the fish landed were not of Norwegian origin, but they boosted Norwegian catch figures. Hence more fish then than now.

Conclusion three. Whilst the Council for Wild Salmon Management (VRL) declare that sea lice pose one of the greatest risks to sea lice, their 2022 report shows that the number of salmon returning to Vestland has increased since around 2007 and that increase is greatest in Vestland than anywhere else in Norway.

Conclusion four. As part of the Salmon Tracking project, eleven rivers are monitored with cameras. All these rivers show a better increase in sea trout numbers than catches and theoretical calculations show.  Sea trout appear to be thriving in Vestland.

The fifth conclusion draws from the observation that there is significant mixing of fish between rivers suggesting that management of sea trout should not be river specific but from a regional perspective.

The sixth conclusion is based on the theory that infested sea trout return to freshwater to rid themselves of lice. In fact, few sea trout in Vestland appear to return prematurely to freshwater. This is despite claims by NORCE that sea lice are of scandalous levels.

Conclusion seven is that there are few mature sea lice on farmed salmon, and it is the modelling hat is wrong. The models used by the theorists assume the fish are at 3 metres depth whereas they are more likely to be at 15-25 metres where the water is colder, and development of lice is much slower. Similar assumptions have been made about salinity which are incorrect.

In addition, the IMR data shows that lice levels are less in one area near farms than at sites 40 km from the nearest farm.’

Finally, the eighth conclusion is that there is no correlation between the observed lice numbers on wild fish and the presence of aquaculture activity as highlighted in Sognfjord.

What is clear is that for far too long, the salmon industry has been influenced by theoretical science that has no bearing to the reality of what is happening in the water. The science has been controlled by a small; clique who not only generate the science but also use it to unnecessarily regulate the salmon farming industry. However, the greatest concern is their unwillingness to be open and transparent about the work. As more and more evidence become available, there will be greater realisation that the models used to predict sea lice infestation mask a basic lack of knowledge of sea lice ecology and biology.

Of course, this is not a problem unique to Norway but is rife wherever salmon are farmed based on a narrative initiated by anglers that salmon farming has ruined their sport.