Salmon farming has done ‘enormous harm’ to fish stocks and the environment, Jeremy Paxman has warned, as he called for an overhaul of the industry to protect wildlife.

The presenter, and keen angler, said many fisheries traded on the image that salmon arrived at the table ‘fresh from the wild seas’ when, in reality most has been bred in cramped, filthy cages in the sea.

There are now 250 salmon farms on the western coast of Scotland, but the surge has coincided with a collapse in the number of wild salmon in the area.

Fish cages are mostly sited near the shore, or in estuaries for easy access, but the overcrowded conditions is a breeding ground for sea lice which infect wild fish when the begin migrating from the sea up rivers.