salmon deaths

Millions of dead salmon dumped, burnt or destroyed

Nearly half of Scotland’s salmon farms burn, dump or destroy millions of dead fish every year, according to Scottish Government data analysed by The Ferret.

While 42 per cent of farms turn their dead fish into energy, animal by-products or compost, 45 per cent end up as landfill, are incinerated or disposed of as waste.

Carcasses are regularly hauled for hundreds of miles across Scotland in trucks, and have been shipped as far afield as Denmark.

Campaigners said it was a “scandal” that dead fish were dumped in landfill sites or “going up in smoke”. They warned that “these kind of practices threaten Scotland’s reputation as a place of quality food and drink” and said record level of deaths showed the industry needed “a radical overhaul”.

But the salmon farming industry stressed that all mortalities were “disposed of in full accordance with Scottish Government regulations”. It said it was committed to environmental protection and establishing “a circular economy” for organic waste.

Scottish animal by-product regulations require salmon farms to appropriately dispose of their mortalities and according to Scottish Government guidance, dead fish can be incinerated, composted, turned into biogas or used as fuel combustion. Carcasses can also be landfilled or turned into organic fertilisers after they are processed.

How salmon farms disposed of dead fish in 2020

General disposal methodNumber of fish farms that use this method Percentage of total number of disposal methods
Waste to Energy5038.46%
Waste Processing1310.00%
Stored in containers129.23%
Animal by-product processing53.85%
Domestic waste53.85%
Other Recycling21.54%
Not listed10.77%
Source: Marine Scotland's Fish Health Inspectorate

The government’s Fish Health Inspectorate inspected 123 salmon farms around Scotland’s west coast and islands in 2020, and recorded how mortalities are handled. In the vast majority of cases one primary disposal method was listed, with seven listing a secondary method.

The Ferret analysed the data to find out where all the dead fish end up. Comparing the inspectorate’s data with 2019 official salmon mortality figures suggests that between 4.4 and 8.9 million salmon may have been buried, burned or wasted in 2020, with 4.1 to 8.2 million turned into energy or products.

At 58 sites dead fish were sent to be incinerated, landfilled on North Uist, processed as waste in factories, or put into domestic waste. A total of 54 fish farms said their dead salmon were sent to factories to be turned into energy or products, or to be composted.

Twelve fish farms said that dead salmon were stored with no final disposal method listed. The inspectorate noted that dead fish were regularly transported across Scotland in trucks and had been transported to Denmark, to be used as biofuel.

Our investigation into the disposal of dead fish is part of a series on fish farming in partnership with Italian journalist, Francesco De Augustinis. It was funded by, an independent, non-profit organisation in Brussels that supports cross-border investigative journalism.

Millions of Scottish salmon die prematurely in fish farms each year, mainly due to viral, bacterial and fungal infections. They are also killed by algal blooms and by mistakes with chemicals or de-licing machines. 

Deaths on farms have now reached record levels. In July 2020 The Ferret reported that mortality rates had quadrupled in nearly two decades and risen faster than salmon production.

Some 25,772 tonnes of salmon died prematurely in 2019, higher than in any previous year. Depending on their size, that could amount to between 10 and 20 million dead fish.

Waste from fish mortalities must be disposed of at an appropriate site managed by the Scottish Environment Protection Agency. The UK Government’s Animal & Plant Health Agency is responsible for regulating the safe disposal and transportation of dead fish.

That millions of Scottish salmon are still buried in landfill is a scandal

Don Staniford, Scottish Salmon Watch

The campaign group, Scottish Salmon Watch, was scathing about the way dead fish were managed. “The Ferret’s forensic data analysis finally puts flesh on the bones of diseased-ridden Scottish salmon,” said the group’s Don Staniford.

“Millions of Scottish salmon carcasses are quite literally going up in smoke via incinerators and waste energy plants. Next time you turn on the kettle in the ad break at Coronation Street the power may have come from Scotland’s diseased salmon farming industry.”

Staniford added: “That millions of Scottish salmon are still buried in landfill is a scandal. The stench of Scottish salmon pervades the highlands and islands of Scotland.”

The Scottish Greens argued that the number of fish deaths showed that large fish farming operations had failed. “It has been clear that industrial scale fish farms in Scotland have a legacy of appalling poor welfare conditions and environmental damage for some time now,” said the party’s environment spokesperson, Mark Ruskell MSP.

“Any system of farming that has such a high level of mortality in its livestock is demonstrably failing. As well as pollution and endangering Scotland’s biodiversity, these kind of practices threaten Scotland’s reputation as a place of quality food and drink.”

From Dumfries to Denmark – where dead fish end up

At 23 sites the destination for dead fish was named as the firm, Dundas Chemicals, which is based in Dumfries, 300 miles south of some farms. The company’s Norman Watt told The Ferret that carcasses were dried and rendered to extract oil and fishmeal protein.

“The protein gets supplied to power stations for combustion and the oil goes into biodiesel for the same purpose,” he said.

The Pelagia facility in Gremista on Shetland was used by five salmon farms to dispose of carcasses. The company extracts fish meal and oil to be used in feed for fish and other animals, according to its website. Pelagia did not respond to our requests to comment.

Of the 22 fish farms that incinerated their dead, all 19 burnt them on site. Three farms sent their carcasses to incinerators on Bressay in Shetland, Twatt in Orkney and Ormsary in Argyll.

Some 16 salmon farms in the Outer Hebrides sent their dead fish to a landfill on North Uist run by Whiteshore Cockles. The firm is promising to replace the landfill with a processing plant to turn the carcasses into fish oil and fishmeal. 

Despite its guidance to the contrary, the Scottish Government allows fish to be buried at Whiteshore Cockles without being processed first. “Until the processing plant is operational, the site has a derogation to landfill salmon mortalities without processing,” the government told The Ferret.

In 2018 the government said the system had “taken longer than originally planned” and was expected to be operational later in 2018. However, the plant has not yet opened.

Whiteshore Cockles said that it had spent years “designing and constructing a unique drying system plant” and that engineers would “connect the final pipework to the plant to make it operational” when coronavirus lockdown restrictions were eased.

“The long term target for the fish oil is to have a biofuel production plant on site and to distribute this fuel to the fish farms at a discounted rate to use in their vehicles, as well as using it to power our own generators,” stated the firm’s Ralph Thompson.

“The fishmeal will be used as a fuel for our biomass burner which in turn distributes its heat to the drier.” The plan was for excess energy to be used to heat a community-owned grain drier and fuel sea salt production.

Whiteshore Cockles was also researching ways to turn excess fishmeal into products for the local crofting and fishing community, Thompson said. This would “provide economic and environmental benefits to the local community”.

Thompson added: “The fish farming industry in these islands has helped to stem the tide of depopulation as it employs a high percentage of our working population and provides them with job security and an excellent standard of living.”

Twelve fish farms in the Northern Isles sent their dead salmon to Total Waste Management Alliance (TWMA), a Shetland waste disposal firm. According to a 2008 feasibility study into turning fish waste into renewable energy, liquid waste from salmon carcasses were treated by TWMA “and exported for further processing on the Scottish mainland”. TWMA did not respond to requests to clarify its current disposal method.

The most common waste-to-energy incinerator named was the Energen biogas facility in Cumbernauld, which was used by 11 fish farms. The plant generates electricity from food waste and food processing residues.

Six salmon farms sent their carcasses to be made into biogas at Keenan Recycling, which has depots in north east and central Scotland.

Others sent dead fish to the waste-to-energy incinerator near Lerwick in Shetland, the Scottish Water Horizon plant in Cumbernauld, the Clancy Consulting Barkip Biogas Facility in North Ayrshire, and the Gask Farm Biogas Plant near Turriff, Aberdeenshire.

Two Sutherland fish farms, run by Loch Duart sent their mortalities to Gray Composting in Banff, Aberdeenshire, while two Grieg Seafood farms in Skye sent their dead to be recycled at Anglo Scottish Biosolids near Falkirk – 250 miles away.

A dead salmon spill near Laggan (photo thanks to Corin Smith)

In a September 2019 visit of a Mowi’s Bagh Dail Nan Cean (BDNC) site at Loch Melfort in Argyll, the fish inspectorate noted that dead fish were sent to Denmark to be used as biofuel.

A Mowi spokesperson told The Ferret: “A combination of environmental and health events at our BDNC farm in the summer of 2019 required quick action to responsibly deal with a sudden spike in fish mortality. The best-suited and available vessel at the time arrived on site quickly to safely retrieve and dispose of the additional mortality.

“Having this vessel available at times when we are witnessing increasing sea temperatures is a responsible contingency plan, but we have fortunately only required its services this one time.”

Mowi, which claims to be the world’s largest salmon farming company, stressed that it was working to tackle fish deaths and was committed to “the most sustainable and circular re-use or disposal routes” when mortality does occur.

All mortalities are disposed of in full accordance with Scottish Government regulations

spokesperson, Scottish Salmon Producers Organisation

The Coastal Communities Network, which involves 18 local groups in Scotland concerned about the marine environment, criticised the high number of premature deaths at salmon farms. “Clearly something is wrong with the production methods being used if so many farmed animals are dying,” said the network’s John Aitchison.

He highlighted the climate pollution caused by the disposal of millions of salmon carcasses. “Saying that some of these dead fish have been used to generate biogas or electricity does little to change our opinion that this industry needs a radical overhaul,” he argued.

A Scottish Government spokesperson said: “Mortalities in fish farming arise for a wide range of reasons. We are working with the fin-fish sector, regulators, scientists and fish veterinaries on a collaborative basis within the Farmed Fish Health Framework to better understand the causes of mortality and how they could be addressed.”

A spokesperson for the Scottish Salmon Producers Organisation said: “All mortalities are disposed of in full accordance with Scottish Government regulations. The Scottish salmon sector is committed to protecting the environment, including working with public and private sector partners to establish a circular economy for any organic waste.”

The Excel spreadsheet of our analysis of reports by the Scottish Government’s Fish Health Inspectorate, with links to source documents, can be downloaded here.

This story is the fifth in a series on fish farming funded by, an independent, non-profit organisation in Brussels that supports cross-border investigative journalism. Our investigations were carried out in partnership with the Italian journalist, Francesco De Augustinis.


Cover image thanks to Corin Smith. This story was published in tandem with the Sunday National.

  1. Would be good to know what percentage of the production ends up as waste to put it in perspective if you could provide that information? or to give an average death rate for farmed salmon in Scotland. Would also be good to know if there are exemplary salmon farms in Scotland with very low death rates or if all of it is that bad? had no idea that the production was actually so huge and that massive death rates

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