reLAKSation no 1059

Worst ever:  Intrafish reports that according to the Norwegian Environment Agency, 2021 was the worst ever year for salmon fishing in Norway since 1956.

In 2021, 289 tonnes of salmon were caught by rod and line whereas the previous five-year average was 427 tonnes. A further 98 tonnes were caught at sea. Ellen Hambro, Director of the Environment Agency says that this is the worst ever in Norway. The previous lowest figure was in 1956 but then the catch was based on reports from a third of the number of rivers that report today.  The agency had expected reduced catches after stricter regulations were imposed last year with reduced ability to fish at sea and the closure of many more rivers. Ms Hambro said the large decline cannot be explained just by the revised fishing regulation or by poor fishing conditions, but the fact that fewer salmon than ever before have survived their stay in the sea and been able to return to the rivers is a real concern. She said that the new regulations were in response to data from the last five years, but these may not have been sufficiently strong given the latest catch data. She added that they must now wait for the status report from the Scientific Council for Salmon Management (VRL) before knowing whether there was enough salmon in the river to sustain good reproduction.

The news of a collapse in the salmon catch comes as no surprise as the writing has been on the wall for many years and a similar collapse was seen in Scotland a decade ago. The reality is that the number of wild salmon returning to freshwater has been in decline for many years. ICES has shown this decline for Scottish salmon from as far back to 1971 but as Prince Charles told the Atlantic Salmon Trust 50th Anniversary dinner in 2017, we have no idea why this is happening. What is much clearer is the outcome. In Scotland, the decline manifested itself as a collapse of wild salmon on the west coast where rivers are small and have even smaller stocks of fish. Fewer returning salmon meant that eventually the breeding stock could not be maintained. As everyone now knows, this collapse of west coast fisheries was of such a surprise that the blame was directed at salmon farms. Yet, after 2010, salmon stocks collapsed again. This time in the east, where no salmon farms were present to blame. By 2011, the reservoir of salmon in the much larger east coast river was exhausted and stocks began to collapse. It is estimated that they could be extinct within thirty years.

Now a similar picture is emerging form Norway where despite limits on exploitation, the number of returning salmon has finally dropped to an unsustainable level. Norway salmon have probably held out much longer than their Scottish counterparts due to the shorter distance to the feeding grounds and the cooler water temperatures, but this collapse in the salmon catch was inevitable.

Although Norway has been more progressive than Scotland in recognising that some aspects of exploitation need to be controlled by closing some rivers and a much shorter fishing season, the data shows that over recent times, catches by rod and line have increased. Whilst Ms Hambro highlights a five-year average of 427 tonnes in the late 2010s, during the early 1990s the comparable figure was just over 300 tonnes. Data from earlier catches is not readily accessible, but the picture is clear that up to an extra 100 tonnes of salmon were caught most years from the early 1990s onwards at a time when returning salmon were certainly in decline.

The annual report from VRL makes it difficult to identify the trends. Their graph shows the exploitation of sea and rivers catches and the remaining spawning stock.

The way the graph is presented gives the impression that the overall number of returning salmon has increased as has the spawning stock. Clearly this is incorrect.

Unlike Scotland, the ICES data for Norway does not begin in 1971 but only as late as 1983. The data is given as an estimate, which is calculated from a run reconstruction model. This uses data provided by the Norwegian authorities to estimate the number of returning fish.

The graph suggests that over the last couple of decades, the decline has stopped and possibly reversed, yet all other evidence across wild salmon’s range would indicate that the fish is in trouble. Why would Norway be any different?

I suspect that it isn’t, but instead the scientific view has become so fixated by trying to blame the salmon farming industry as the main problem facing Norway that they have not really given the issue of returning salmon the consideration it deserves.

In their latest annual report, VRL continue their claims that salmon escapes and sea lice from farms are the biggest threat to wild salmon, yet VRL offer nothing new to support this view. They still use their 2019 figure of an estimated reduction of 39,000 salmon. VRL continue to remain silent that the estimated loss of 39,000 smolts is a bigger threat to Norwegian salmon stocks that the killing of over 100,000 adult breeding salmon by anglers for sport. Surely, the loss of these fish travelling upstream to breed is a much greater threat to the viability of the stock than the estimated loss of many less smolts. VRL offer no evidence that any of these fish actually died.

VRL are quick to offer their views on what constitutes the greatest threat to wild fish despite stating that the number of salmon returning to River Imsa between 2009 and 2018 was between 1-4% down from 17% in the 1980s. As Prince Charles told the audience of the AST dinner, which included King Harald V of Norway, we don’t know why this is happening. This is what we really need to know but until we do, the answer is surely to cease exploitation and close all rivers in Norway to fishing. Of course, this won’t happen and whilst catch and release is no solution, the current rate is only 31% in Norway. Perhaps, catch and release should be mandatory.

As to why marine survival is so low and fewer fish are returning to rivers to breed, I have written previously about the underestimation of the predatory mackerel stocks and the potential that seismic surveying for oil can interrupt salmon’s ability to navigate. Sadly, the scientific community aren’t interested in such theories because they are all too busy blaming salmon farming, even though the declines began in the early 1970s long before salmon farming expanded into the industry it is today.

 

In Memoria:  Since the pandemic, there has been increased interest in planting a tree as a commemorative a departed loved one. Memorial forests are quite common in northern England, but the concept is now expanding across the border to Scotland.

However, it seems that the River Dee Salmon Fishery Board are ahead of the game. According to the Guardian newspaper, 250,000 trees have been planted alongside the River Dee and its tributaries. I can only see this as commemoration of the Atlantic salmon as it heads towards inevitable extinction. The River Dee hope to expand this memorial to over a million trees by 2035 by which time salmon may no longer be seen in the river.

The Guardian states that fisheries’ scientists have found rivers and burns in the Highlands are already too warm in summer for Atlantic salmon as they head upstream to spawn and these high temperatures increase the threat to the species’ survival. However, the Guardian also included a graph showing salmon catches in the River Dee have fallen by 80% since their peak in 1957 but the article doesn’t actually refer to its inclusion.

The sad fact is that the River Dee has been in decline for many years. For the last twenty years, the river has been catch and release only but this has not stopped the decline. Planting trees is simply a sticking plaster strategy which fails to address the underlying issues.

The paper also spoke to Alan Wells of Fisheries Management Scotland who said that climate forecasts were clear that water temperatures would continue to climb and as this gets worse there is need to create a cooling shade.

The Guardian also mentioned that the dramatic decline of wild salmon is blamed on numerous factors including climate change, weirs and dams, predation by seals, bycatch by trawlers at sea, poor river quality as well as sea lice from salmon farms, even though the Dee is hundreds of miles from any salmon farm. Dr Wells said that whilst Scottish Ministers were proposing new conservation measures, he remained frustrated with the slow pace of change.

Seemingly, the Guardian did not include all of the possible reasons for salmon’s decline. Instead, it mentioned that the River Dee angling season opened this week with an invitation to two female anglers who won a competition last year to make the first cast. One of the first cast fishers was Camryn Stewart aged 14 who had been brought up in a fishing household.  She said that she has been surrounded by people who fish, encouraging her to join the sport. She added that more people should come fishing, not just women and children. Just being outside in the wild even if you don’t catch anything means you come back from the day fulfilled. This is good news because the likelihood is that Ms Stewart will increasingly have to rely on being fulfilled without catching anything because unless radical action is taken to safeguard wild salmon, there will be soon none left to catch.

 

Solid study: Eva Thorstad, a member of VRL, recently tweeted about a new paper showing that sea trout are at a high risk of sea lice infestation from salmon farms. She describes the work as a solid study from Norwegian colleagues which might make one wonder how other work can be described. The paper is titled ‘Salmon louse infestation levels on sea trout can be predicted from a hydrodynamic lice dispersal model’ by Thomas Bøhn and his colleagues. The paper describes how in areas of high density of farms, more than 50% of sea trout experienced infestations above the levels of expected serious health effects providing yet more proof about the damaging effects of salmon farming and supporting the view that salmon farming is the greatest threat to wild fish in Norway.

Yet, words that appear in the paper’s title such as ‘predicted’ and ‘model’ lead me to express concern that such modelling does not reflect what is actually happening in the sea. The raw data for the paper is available and yet again, the lice count reflects an aggregated distribution where most hosts have no or few lice whilst a few have a high lice count.  Of nearly three thousand sea trout, just eight had counts of above three hundred and these were mainly larval lice which are known to drop off host fish. Another twelve fish have counts ranging from 200 to 300 lice and 117 have counts between 100 and 200. The graph shows the counts between 0 and 50 lice.

It is difficult to comprehend how the paper claims that more than 50% of sea trout experienced lice infestations in farming areas when 83% of the sample carried less than ten lice.

Part of the problem is that the paper uses the infestation levels quoted by Taranger et al (2015) and these have now been questioned by the Evaluation Committee of International Scientists commissioned by the Norwegian Government to assess the Traffic Light System. Their recommendations were critical of the way in which the mortality levels were assessed. They recommended that studies should be undertaken and peer reviewed to provide data on in situ effects of lice infestations on wild salmon at an individual and population level. They also recommended that the mortality levels should be regularly reviewed as new information comes available. Taranger’s model was formulated over ten years ago and no further work appears to have been conducted to ascertain how relevant the mortality model is today.

It is interesting that Geir Lasse Taranger was interviewed by the Institute of Marine Research in which he said that the committee have done a good job but that they did not come up with anything where they said that the research was wrong. Instead, he says that they have provided input into what knowledge and approaches can make the traffic light system even better.

I, for one, have asked Dr Taranger how the mortality model reflects the aggregated distribution, as shown above, which is common to all of the large samples collected around the Norwegian coast. I am still waiting for an answer.