The angling group, Salmon and Trout Conservation Scotland (S&TCS), has attacked the supermarket chain for continuing to market caged salmon from the north west coast of Scotland that could harm wild fish.
Salmon farms have long had a problem with sea lice, tiny natural parasites that eat fish alive. Lice can multiply in cages holding many thousands of salmon, and then spread to passing wild young salmon and sea trout and kill them.
S&TCS complained a year ago that Sainsbury’s salmon came from fish farms that failed to meet industry guidelines on lice infestation. The group was then assured by company managers that the problem was being dealt with, and lice infestations would end.
But S&TCS says that lice levels on salmon farms at Loch Duich, Loch Alsh and Ardintoul near the Isle of Skye breached the industry’s good practice code in the last three months of 2015. In December average levels reached nearly seven adult female lice per fish, compared to a recommended threshold of one.