Scottish salmon sold by a range of supermarkets in the UK has sea lice up to 20 times acceptable limit

Tesco, Sainsbury’s and Co-op are among those who have stocked salmon from the worst affected farms

Campaigners have called for change (File photo)

Scottish salmon sold by a range of supermarkets in the UK has sea lice up to 20 times the acceptable amount.

The maximum number of the parasites is expected to be no more than one louse per farmed fish but data obtained by the Salmon and Trout Conversation (S&TC) Scotland shows that there was an average of at least three lice per farmed fish at Salmon farms.

Tesco, Sainsbury’s and Co-op are among those who have stocked salmon from the worst affected farms and Co-op’s supplier, The Scottish Salmon Company, recorded lice numbers that exceeded acceptable levels at six of its 10 farms, for an entire year.

At one of the farms, each fish was found to have 23 sea lice for a period of seven weeks.

Tesco salmon supplier Grieg Seafood Shetland was found to have an average of 22 lice and Marine Harvest, Sainsbury’s supplier was also on the list.

Those fish who are infected pose no risk to consumers as they are either discarded or treated with pesticides.

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.

“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.”