reLAKSation no 870

The Martin Jaffa School of Statistics: The announcement over last weekend that the Scottish Government intends to establish a ‘Salmon Interactions Working Group’ has provoked some criticism ranging from ‘just another talking shop’ to ‘another PR piece for the salmon farming industry’. The intention is to look at the interactions between farmed and wild salmon and provide expert advice ‘on mitigating pressures on wild salmon’.

The Sunday Herald appeared to have an exclusive on the announcement of the new working group and amongst the details it reported was that ‘the population of wild salmon in Scotland has fallen by 50% from around 1.25 million fish in the 1960s to 600,000 in 2016’. The newspaper continues that ‘angling groups point out that most of the decline is on the west coast, close to where salmon farms are located’.

In terms of measuring salmon stocks, Marine Scotland Science (MSS Reports 02/16) state: ‘rod catches have traditionally been used as indicators of abundance of Scottish salmon stocks’. In 1952, the first year rod catches were officially recorded, 33,910 wild salmon and grilse were caught from east coast and the Ayrshire coast rivers. A further 6,178 salmon and grilse were caught from rivers in what is now classed as the ‘Aquaculture Zone’. The total catch was 40,088 fish. The split between the two areas was 85%/15%. If all the salmon and grilse caught from the ‘Aquaculture Zone’ were lost then the largest possible decline could only be 15%, yet according to the Sunday Herald, the total decline of wild fish is 50%, most of which is supposed to have been lost from the west coast.

One of the salmon farming companies attempted to correct the statement in the Sunday Herald by tweeting ‘one key correction is that Marine Scotland Science data shows wild salmon has declined much more significantly on the east coast where there are no salmon farms’.

This graph shows the total number of fish caught by all methods including nets and as such may not reflect the total stock in the same way as rod catch data. In part, the decline in catches is due to the reduced number of nets operating along the east coast. Currently, commercial netting of wild salmon off shore is banned.

In response to this tweet, one salmon industry critic from the angling sector wrote on Facebook that ‘someone has been attending ‘the Martin Jaffa school of statistics’. He said that the graph is the worst kind of industry spin and fake news and gives the reasons why:

1.‘The freshwater fisheries laboratory did not produce the chart. It is an analysis by the salmon farming industry’. Actually, he’s wrong. It says that it is Marine Scotland data and the source, as in the source of the data, is the Freshwater Fisheries Laboratory.  If Marine Scotland had taken the same data and compiled the graph, it would look exactly the same. This is simply semantics.

2. Of much more interest is that he says that ‘if you want to analyse east and west coast catches, you need to make a relative analysis, not look at absolute numbers. You need to re-base the catch numbers for both coasts to zero (as, he says, anyone with a basic grasp of statistics and a genuine interest in finding honest answers would do). If you do this, west coast rivers do show a relative decline in catches far greater than the east coast over the period of the advent of salmon farming’. He adds, ‘unless the intention is to mislead’.

Unfortunately, attendees to ‘the Martin Jaffa School of Statistics’ would know that re-basing the catch data to zero is more misleading than it is illuminating. This is because by starting at zero, anything that happened before is erased. This can be seen from the graph produced in 2011 by the Rivers and Fisheries Trusts of Scotland (RAFTS) which compared east and west coast catches from 1970 onwards. The graph presents the data for 1970 as 100% for both coasts.

The problem with this graph is that the world didn’t start in 1970. Wild fish stocks were already in decline in 1970.

Critics will say that the dip in catches in the late 1990’s has influenced the trend during the beginning of the series. However, this is balanced out by the three peaks during the 1960’s. These peaks were the result of unusually high catches in just three systems, the Awe, the Lochy and Loch Roag. The picture is clearer for sea trout.

Despite strenuous efforts on our part, we have yet to hear one single explanation as to what is happening to sea trout catches as illustrated in this graph. Catches were clearly in decline prior to the arrival of salmon farming but the wild fish sector has remained strangely reluctant to provide any explanation of why catches have declined.

Resetting catches to zero eliminates the earlier declines. There is also a second problem with the RAFTS graph. This is that the river systems on both coasts are very different. For example, the River Tay is 188 km long whilst the River Ewe is just four. Clearly, the size of the stock is very different, and this is reflected in the length of the fishing season. Last year, the Tay was recording catches of salmon from January to October, whilst catches from the Ewe only began in May. This means that the Tay and other east coast rivers have a significant advantage over west coast rivers and why it is better to compare overall catches than percentage change as conducted by RAFTS.

However, the biggest question arising from resetting the start of a time series is the very fact it is an arbitrary choice.  If the start date is changed, then the picture presented can be very different. For example, a start date of 1990 rather than 1970 results in the following graph:

Catches from both east and west coast are now seen to increase. Clearly, salmon farming is not having the impact as claimed.

If the start date is moved to the year 2000, then the outcome changes again:

Now it seems that the west coast is out-performing the east.

Finally, there is one graph that is worth sharing and this is the comparison of sea trout catches from east and west coast. This is based on numbers and not percentage change. We’ll leave you to draw your own conclusions because ‘the Martin Jaffa School of Statistics’ is now closed.


A dose of realism: The advocate of ‘the Martin Jaffa School of Statistics’ also mentioned that ‘the new salmon farm interaction group has a remit only to look at how to mitigate the effects of industrial open-cage salmon farming on wild fish. He goes on to say that it is a farmed salmon industry body without proper wild fish representation and not independent. It has no remit or scientific expertise to examine or comment on wild fish declines generally’.

This is an interesting take on the announcement made by the Scottish Government regarding a new ‘Salmon Interactions Workstream’, part of which is a working group whose initial task is to examine the interactions between wild and farmed salmon and recommend how any impacts can be minimised. The membership of the group will come from the aquaculture and wild fisheries sectors, Marine Scotland, SEPA and Scottish Natural Heritage. We are not sure where the idea that this is a farming industry body and whether it is able to comment on wild fish generally, has yet to be determined.

Commenting on an article in the Sunday Herald, a later post states: ‘The Scottish Government response to declines in wild salmon populations across all of Scotland is to create a working group chaired by an ex salmon farmer, with multiple salmon farming bodies represented, to look at issues on the Tay, Tweed, Spey and Dee’. He says that the various Salmon Fishery Boards ‘must be looking forward to the invaluable guidance they are going to receive from salmon farming companies’.

We, at Callander McDowell have been looking at the state of wild salmon and sea trout stocks for the past eight years and one thing that has consistently struck us is the repeated comment/advice/criticism of the farming sector from wild fish interests. Yet, as soon as the most innocuous comment is made from farming interests about wild fish, there is uproar with the suggestion that the farming sector are not qualified or informed to talk about wild fish. This is reflected in various groups etc where wild fish interests demand involvement in farming policy yet, the wild sector is off-limits to those with a farming background.

Instead of such polarisation, perhaps it might be helpful if everyone would sit down together and talk. We have been advocating this for some time, and now it looks as if the Scottish Government has recognised the value of working together too. The working group appears to include representatives of both wild and farmed sectors and rightly so. We certainly welcome the formation of this group and hope that everyone else does.

We would suggest that this working group needs to go back to the beginning and start from scratch as to looking what impacts there are. There is a lot of misinformation in circulation and this needs to be disposed of together with any preconceived views. For example, a different critic told the Sunday Herald that ‘the time for talking and yet another working group is well and truly over’. Actually, the time is right for talking and everyone should welcome it and embrace it.

We do know that some conservation has been taking place through the auspices of Prince Charlies’ Sustainability Unit. We had read in ‘Fish Farmer’ magazine that one proposal recommended that the farming industry should create a fund to help restore wild fisheries.

In a similar vein, the latest Fisheries Management Scotland Annual Review stated that they wished to see ‘investment of a proportion of any profits generated into the protection and improvement of local salmon and sea trout populations and fisheries’.

The wild fish sector appears to have an expectation that salmon industry money should be used to help protect wild fish. In our view, this is unrealistic for a number of reasons, not least because of what it implies. We are certainly of the view that any known impacts of salmon farming do not warrant such payments. However, if individual farms want to help local interests that is a completely different matter.

Whilst we were looking at the FMS Annual Review, we noticed an article from land valuers Strutt and Parker that includes a valuation of salmon and seatrout from different river systems. A salmon caught from one of the big rivers is valued at £5,000 to £7,000 whilst one caught from an island river is valued at £2,500 to £4,000. Sea trout valuations range between £1,000 to £2,000. With such assessments, perhaps one way to raise funds to improve the fisheries would be to charge the appropriate valuation if any angler wanted to retain any fish they caught. We haven’t done the maths, but such an approach could raise many millions of pounds that could be reinvested back into fisheries and research.

The real problem is wild fish are in decline across all their ranges, not just where salmon farming operates, and no-one seems to know why. The Atlantic Salmon Trust are currently pursuing their ‘Missing Salmon Project’ in which they will track migrating salmon down rivers and out into the Moray Firth. This week the ‘Forres Gazette’ reported that the River Findhorn fishery trust believes that the number of juvenile salmon leaving the river is satisfactory. The local problem highlighted by the newspaper is that about 700 seals are currently living around the mouth of the river.

A number of other rivers have reported that juvenile numbers are also satisfactory which would suggest that the problem for wild fish occur out at sea. The tracking project is not going to find answers to this problem. Whilst increased predation is an issue, the underlying problems appear to spread further afield. Some years ago, skinny grilse were an issue. This could have been the result of reduced food supplies. Maybe now the food supply is much worse, and the fish are no longer skinny but starved to death.

The question is really what action is needed. Moving salmon farms is not the answer, but since fisheries managers have yet to find ways to reverse downward trends, perhaps a different view might help. After all, as the saying goes, many heads are better than one. If they can be of help then why shouldn’t some of these heads come from the salmon farming industry?


100% sure: The main news story about salmon farming in Canada concerned whether twenty farming sites would have their leases renewed.

According to CBC News, opponents to salmon farming fear the impact of sea lice from farmed salmon on wild Pacific species. Leading critic for over thirty years, Alexandra Morton said that ‘I’m 100% sure that these farms are killing off wild salmon’. She added that ‘When you look everywhere in the world, Norway, Scotland, Ireland, Faroe Islands, Eastern Canada, Western Canada, wild salmon go into precipitous decline as soon as the industry operates’.

By coincidence, Seafood News reports that a dismal run of sockeye salmon has prompted an ‘unprecedented’ shutdown of dip netting at Chitina. About 7,000 people typically dip net at Chitina every summer for their personal use. The season normally lasts from June to September and averages about 170,000 salmon a year. This is the first year since 1959 that the fishery has been closed to dip netting. The 2018 sockeye run appears to be much weaker than expected which is why a ban on dip netting has been put in place.

The significance of this news is that Chitina is located on the famous Copper River, which even Alexandra Morton knows is in Alaska where there is no salmon farming. The nearest farm is about 2,000 miles away. Chitina is not an isolated example. Wild fisheries are in decline across the Pacific. Surely, even Alexandra Morton would not suggest that the unprecedented decline in Copper River salmon has anything to do with salmon farming. The reality is that wild salmon stocks are in decline across the world and critics such as Alexandra Morton are simply using salmon farming as a convenient scapegoat.