New data showed that farms supplying salmon to major UK supermarkets were infested with lice (Picture: Andrew Burton/Getty Images)

Leading supermarkets have been called on to stop selling salmon reared by certain Scottish farms because they have sea lice infestations up to 20 times the recommended level.

Co-op, Tesco and Sainsbury’s all stock salmon from the worst affected farms, according to new data from Salmon and Trout Conservation Scotland.

Salmon farms are expected to keep numbers of the parasite – which can cause loss of fins, scarring, secondary infections and death – to no more than one louse per farmed fish.

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But the data listed farms with an average of at least three lice per fish being farmed.


Fish at Score Holm farm, run by Tesco salmon supplier Grieg Seafood Shetland, were found to have an average of 22 adult female lice.



At the firm’s Furnace Quarry farm, each fish was found to have 23 sea lice for a period of seven weeks.

Meanwhile Co-op supplier, The Scottish Salmon Company, recorded lice numbers that exceeded acceptable levels at six of its 10 farms, for 52 weeks.

Marine Harvest, which supplies Sainsbury’s, was also named on the list.

Sea lice have always been relatively common on adult salmon as they return to spawn (Picture: Getty)

The Scottish government said it will work alongside the aquaculture industry to tackle the ‘major problems’ (Picture: Cameron Spencer/Getty Images)

Fish infested with sea lice are discarded or treated with pesticides and pose no health risk to consumers.

Guy Linley-Adams, Solicitor for S&TC Scotland, told the Daily Mail: ‘We now call upon Scottish ministers to rethink radically their approach to the salmon farming industry, to end the knee-jerk support of the industry in the face of frankly awful environmental performance, and to stop trying to protect it from legitimate criticism.

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‘We have shared our ideas for change with Marine Scotland and hope Scottish ministers will now work with environmental and conservation bodies to map out a sustainable future for the industry that no longer damages the precious Scottish marine environment and the species within it.

‘We also call upon the industry itself to end both its tobacco-industry style denials about the damage it causes and the “tit for tat” accusations it repeatedly makes, in favour of embracing the positive change that must now come.’

What can shoppers do? Is it still fine to buy Scottish salmon as fish infested with sea lice are discarded or treated with pesticides so they pose no health risk. ‘Retailers ensure the products they sell meet rigid quality controls,’ the British Retail Consortium said.

A Scottish government spokesman said it would work alongside the aquaculture industry to tackle ‘major problems’ including disease and sea lice.

A spokesperson for the British Retail Consortium (BRC), on behalf of Tesco, Sainsbury’s and Co-op, said: ‘BRC members are committed to responsible sourcing, which protects the welfare of fish as well as the wider marine environment, and will review this new data from the Scottish Government.

‘The seafood industry, including retailers, agree on the need to accelerate the widespread adoption of effective sea lice controls, and the Scottish aquaculture industry have set very high standards to adhere to.

‘Whilst a range of alternative technologies and approaches are being trialled by the aquaculture industry, there is no single solution to tackling this problem.

‘Retailers have controls in place to ensure the products they sell meet rigid quality controls, and they have ongoing engagement with their suppliers to address these challenges.’

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