The ‘alternative’ fish species that saw the biggest sales increase last week during Sainsbury’s Switch the Fish campaign was loch trout.

During the campaign, Sainsbury’s encouraged shoppers to venture outside the ‘big five’ fish species of tuna, salmon, cod, haddock and prawns, by offering 20% off.

Loch trout sales increased by 147%, followed by lemon sole, which rose 120%, coley (100%), sardines (35%) and mussels (25%).