Intensively farmed Scottish salmon, supplied to some of the UK’s major supermarkets, are infested with flesh-eating sea lice, campaigners warn, posing a major threat to the health of our oceans.
Investigators for Viva! visited farms in the Highlands where they say fish are being kept in “putrid” overcrowded sea pens – a breeding ground for diseases.
The say not only does this cause suffering and stress for the fish, but it’s also a major risk to the environment.
Last year, 22 tonnes of formaldehyde used to treat the lice was poured into 12 Scottish sea farms.
In 2016, the government classified it as a carcinogen but its use is permitted in the caged salmon industry.
Campaigners say it pollutes lochs, rivers and seas, and is a threat to local wildlife.
Escaped farmed salmon can also cause significant damage to wild populations by weakening the gene pool.
Stocks of North Atlantic Salmon are already in decline due to overfishing and the impact of climate change.
Viva! also said they witnessed dedicated boats patrolling a farm owned by Scottish Sea Farms to “clean” the salmon of the lice using a practice they likened to a “brutal washing machine”.
Scotland is the world’s third-largest producer of farmed salmon, behind Norway and Chile, with Brits eating eight million salmon meals a week.
Lex Rigby, head of investigations, said: “We’re led to believe that aquaculture is the sustainable solution to overfishing, but its rapid intensification has brought with it the same problems we have with factory farms on land.
“The putrid conditions in which farmed fish are reared create a breeding ground for disease that not only causes serious animal welfare issues but also delivers widespread habitat destruction, water pollution and the development of life-threatening drug-resistant superbugs.”
The Scottish Salmon Company, which supplies Co-op, said: “The health and welfare of our stock is of paramount importance. As with any farming, there can be naturally occurring health challenges, such as sea lice, which are endemic in the wild.
“These treatments are specifically designed for the removal of sea lice.
“They are managed by a team of trained professionals and are assessed in terms of welfare by independent third-party organisations.”
Scottish Sea Farms, which supplies M&S, added: “Proactive health treatments such as these are carried out specifically to protect fish welfare, removing lice just as is done with other farmed livestock.”
