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11/11/2020

Alexa, how many salmon die each year on Scottish salmon farms? 42 million* (but we don't know for sure as the answer is deemed "commercially damaging")!

Alexa
42 blog Tweet photo 42 million

 



 

How many salmon die each year on Scottish salmon farms?  Now that may sound like a straightforward question with a simple answer.  Like 42 being the Answer to the Ultimate Question of Life, The Universe, and Everything in the Hitchhiker's Guide to the Galaxy.  As it happens the estimate for the number of farmed salmon mortalities in Scotland in 2019 is an eye-popping 42 million - with ca. 20 million dying in freshwater hatcheries and farms and ca. 20 million in sea cages and via transfers by wellboat (working is shown below). 

 

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Sadly, we have no officially reported data on the exact numbers of dead farmed salmon in Scotland since the year 2012 following lobbying by the 99% foreign-owned 'Scottish' salmon farming industry who argued that public disclosure were be "commercially damaging".

 

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SSPO commercially damaging letter Feb 2013

 

SSPO commercially damaging letter Feb 2013 SEPA March 2013 reply

 

 

 



 

We're therefore left with data up to only 2012 and are faced with mind-bending extrapolation and interpolation to arrive at answers for the years 2013 to 2019.  At least the data from 2010 to 2012 gives actual numbers of mortalities which along with data on weight of mortalities gives an indication of the ratio of mortalities by number to mortalities by weight.  Roughly speaking one thousand tonnes of mortalities = 700,000 dead salmon but this will obviously depend on the stage of salmon farming production (with mortalities in the hatchery when the fish are much smaller weighing less and mortalities in the sea phase of production weighing much more).  

 


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Here's the data set we're working from - as reported by Rob Edwards of The Sunday Herald in 2013 (now one of the big brains behind The Ferret):

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Pythagoras, Einstein, Tao as well as Matt Damon in the film 'Good Will Hunting' would all struggle to decipher the conundrum that is Scottish salmon's mortality problem.  

 

Good will hunting #2

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To find a way through the complexity we would love to have the help of Beth Harmon in Netflix's hit show 'The Queen's Gambit' but that's a work of fiction (in much the same way as the Scottish salmon farming industry's claims of 'healthy' fish and 'low' mortality). 

 

Queen Gambit

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What we do have is data published by the Scottish Environment Protection Agency on the weight (in tonnes) of mortalities - hence we have Rob Edwards reporting in July 2020 via The Ferret article "Farmed salmon deaths from disease reach record high":

 

Ferret 13 July 2020 #1

 

Ferret 13 July 2020 #4

Ferret 13 July 2020 #2 table

 

 

We also have data on mortalities published by the Scottish Government's Fish Health Inspectorate - but this incomplete data set only relates to mortality events which are greater than 1% (i.e. it does not capture all mortalities) and 16% of cases have missing figures.

 

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And we also have data sourced from the Scottish Salmon Producers Organisation (SSPO) which has published monthly mortality and cumulative data since it was forced to do by the Scottish Parliament in 2018 (the way the data is presented is as if the industry - 99% of which is controlled/owned by six foreign companies - is trying to bury the evidence).

 

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In order to pick through the white noise, we have to channel Matt Damon's mathematical genius and use all available data.   Our ballpark answer suggests mortalities in the sea phase of salmon farming production to be as low as 10 million and as high as 25 million per year since 2012 (when data is last publicly available) but then you have to factor in another 18-25 million morts per year in the freshwater phase of production.

 

Good will hunting

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In 2017, The Times newspaper suggested 20 million mortalities on salmon farms in Scotland.

 

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The figure of 20 million mortalities was derived from a report - "RSPCA Assured certification of Scottish farmed salmon" - published in July 2017 by Salmon & Trout Conservation Scotland:

 

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The Scottish Salmon Producers Organisation have obviously downplayed numbers but admitted "somewhere between 6 and 10 million fish" in 2017. 

 

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If we want to calculate total mortality of farmed salmon then we need to go back to imports of ova (eggs) and follow the life-cycle of salmon from hatch in the hatchery to on-growing as smolts in sea cages.  For that we have a useful data set in the shape of an annual fish farm production survey published by the Scottish Government.

 

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Data junkies and geeks will love the information presented in the latest survey for 2019 published in October 2020 - with 63 million to 71 million ova laid down each year leading to 38.5 million to 53 million smolts put to sea (a mortality figure ranging from 18 million to 25 million per year):

 

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So you have something like 70 million ova laid down to hatch each year leading to the annual production of ca. 50 million smolts (i.e. ca. 30% annual mortality during the hatchery phase of salmon farming production). 

 

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Mortality data published by the Scottish Government's Fish Health Inspectorate (data published on 4 November 2020 up to the end of September 2020) details mass mortalities in the hatchery with 118 'Mortality Event Reports' for freshwater salmon farms reported since January 2017 totaling 6.6 million dead salmon.  Here's the top 10 biggest mortality events for freshwater hatcheries since 2017 with Mowi's 1.5 million morts at Lochailort heading the list of shame:

 

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If you look at mortality in the sea phase of salmon farming production there's been a staggering 1,509 'Mortality Event Reports' since February 2017 (data up to the end of September 2020) totaling 13.2 million (with 200+ events not disclosing/reporting numbers).  Here's the top 20 biggest mortality events for sea cage salmon farms since 2017 with Scottish Sea Farms at Snaraness in Shetland heading the list of shame:

 

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If you look just at the data for September 2020, there were 78 'Mortality Event Reports' totaling close to 1 million dead salmon (965,020) - here's the top 10 with mortality rates up to a whopping 43%:

 

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Mortality data for August 2020 was also close to 1 million with 996,329 farmed salmon officially reported as dying due to Pancreas Disease, Anaemia, Cardiomyopathy Syndrome, Gill health, complex gill disease, post treatment mortality, post-physical delicing, Sea lice (Caligus) grazing damage, treatment losses and other issues.

 

 

 

 

 

And expect mortalities in October 2020 to be well over 1 million since it is statistically-speaking the worst month for mortalities accounting for 14% of the year's dead salmon.   Scottish Salmon Watch warned in October 2018:

 

FHI data Aug 2019 #24

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According to Corin Smith at Inside Scottish Salmon Feedlots, mortality rates have increased since data was first published in 2002. 

 

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Here's a report from October 2019.

 

Corin blog Oct 2019

Mort post by Corin 17 Oct 2019 #2

Mort post by Corin 17 Oct 2019 #3

 

 

More recent data published by the Scottish Salmon Producers Organisation - which represents the six foreign-owned companies who together account for 99% of 'Scottish' salmon farming production - paints a shocking picture of diseased and dead Scottish salmon with cumulative mortality over the full production cycle as high as 78.3% (i.e. 4 out of 5 salmon are dying in the sea phase of production).

 

SSPO Sept 2020

 

SSPO Aug 2020

 

 

 

 

 

Here's the worst mortality rates at most of Scotland's salmon farms during July 2020 (not all salmon farming companies - e.g. Kames - are members of the SSPO):

 

SSPO mort data top 14 July 2020

 

 

 

Data published by the SSPO for June 2020 shows lower cumulative mortality but most sites are experiencing mortality rates of well over 10%. 

 

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Of the salmon farms harvesting out in May 2020, the cumulative mortality ranged from 5% to 42%:

 

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Of the five salmon farms which harvested out in April 2020 the cumulative mortality ranged from 10% to 31%. 

 

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Only four salmon farms were harvested out in March 2020 with cumulative mortality ranging from a high of 39% to a low of 12%:

 

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Cumulative mortality at salmon farms which harvested out in February 2020 ranged from a high of 39% to a low of 8.5%:

 

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Cumulative mortality ranged from a high of 40% and a low of 8% at salmon farms harvested out in January 2020:

 

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There's obviously a range of mortality rates between years, sites and even regions but an industry-average mortality rate in excess of 20% would seem accurate with mortality rates rising over the last decade. 

 

 

 

 

 

The 2019 Scottish Fish Farm Production Survey published in October 2020 reported survival rates of 73.8% (i.e. 26.2% mortality) for 2017 (the last year available).  Here's the crucial data which can assist in our calculations.

 

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You can see from the above table that data for 2018 and 2019 is not yet published but the survival rate ranges between a low of 71.8% (i.e. 28.2% mortality) in 2007 and a high of 85.4% (i.e. 14.6% mortality) in 2012.  The survival rate drastically differs between regions too with survival in in 2017 as low as 58.2% (i.e. 41.8% mortality) in the North West and as high as 80.8% (i.e. 19.2% mortality) in the South West:

 

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From the data published by the Scottish Government in October 2020 we know that anywhere between 38 million and 52 million smolts are put to sea each year so a survival rate of say 75% (i.e. 25% mortality) would therefore equate with between 9.5 million and 13 million morts. 

 

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A more simple equation begins with the mortality data that we do possess; namely the 2010-2012 data (published before the Scottish Environment Protection Agency caved into lobbying by the salmon farming industry not to report numbers of mortalities):

 

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And then we take the mortality data (in tonnes) for 2013 to 2019 that has been published:

 

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If 13,627 tonnes of morts equates with 8.5 million farmed salmon (as was the case in 2012) then 25,772 tonnes of morts (as reported in 2019) equates with 16.5 million morts

Or if 9,717 tonnes of morts equates with 6.8 million farmed salmon (as was the case in 2011) then 25,772 tonnes of morts (as reported in 2019) equates with 18 million morts

Or if 7,159 tonnes of morts equates with 5.5 million farmed salmon (as was the case in 2010) then 25,772 tonnes of morts (as reported in 2019) equates with 19.8 million morts

 

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RSPCA 20 million

 

 

Data for the first six months of 2020 is also published via 'Scotland's Aquaculture' web-site with 9,930 tonnes reported compared to 8,610 tonnes in the first six months of 2019.  Here's the top 20 worst salmon farms for morts (up to June 2020):

 

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Since we know mortalities in the second half of the year are significantly higher than in the first half of the year (in 2019 there were 17,162 tonnes of morts in the second half of the year compared to 8,610 tonnes in the first - roughly double) then we could realistically assume there will be perhaps 20,000 tonnes of mortalities in the second half of 2020 with 30,000 tonnes in total.  If so, we could expect maybe 24 million mortalities in the seawater phase of salmon farming production in 2020.   Video evidence certainly suggests that 2020 is another annus horribilis for Scottish salmon.

 

 

 

 

 



 

Video footage from Kames Fish Farming, photos of a mort pit at The Scottish Salmon Company and recent data from Mowi's Glenfinnan salmon farm it is painfully clear that mass mortalities in freshwater salmon farms are becoming hugely significant. 

 

 

 

 

 

Mowi's ASC-certified salmon farm in Loch Shiel (Glenfinnan) reported over 60,000 mortalities in August 2020.

 

FHI Aug 2020 #12 Glenfinnan

 

 

Scottish Salmon Watch has given it our best shot and invites anyone else to come up with an answer which is until there is full disclosure by salmon farming industry will have to remain guesswork.  

 

 



 

Scottish Salmon Watch reckon ca. 20 million farmed salmon die each year in the sea phase of production with another 20 million fish dying each year in hatcheries and freshwater farms.   So from hatch to catch (i.e. from import as eggs into the hatchery to harvest out of sea cages for processing to supermarkets) there could be ca. 40 million morts (maybe even 42 million). 

 

Good Willing huntin #4

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If you have a better guesstimate or an inside track on mortality numbers please do meet the maths challenge.   You never know - the weight of public pressure may force disclosure!

 

 

 

 

 

Scottish Salmon Watch invites other answers and hopes a Will Hunting or Beth Harmon steps up to the challenge.

 


 

 

Please email Don Staniford via [email protected] - and remember to show your working and cite your source material.

 

Dead-salmon-dump-one-via-Corin-Smith

 

 

Note that these mortality figures do not count 'cleaner fish' which are dying in their hundreds of thousands on Scottish salmon farms - but that's another story.........

 

 

 

 

In the meantime, as Douglas Adams wrote: "So long and thanks for all the fish!"

 

So long and thanks for all the fish

So long and thanks for all the fish #4

 

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Posted at 09:05 AM |

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