The UK has introduced new rules for fish labelling for England, Scotland, Wales and Northern Ireland.
The Fish Labelling Regulations 2010 replace the previous regulations, add new commercial designations (the names of fish) for species of fish that have recently come onto the market and give extra options for some others that were already listed.
The regulations are aimed at ensuring fish are labelled correctly and consistently at the point of sale, so that purchasers know exactly what they are buying, whether it was caught at sea, in inland waters or was farmed and, if caught at sea, in what sea area.
More info from Food Standards Agency of the UK