Such farms were meant to provide a salvation for the fragile economy of the Highlands and Islands. Seduced by the prospect of extra jobs, which were never as plentiful as hoped, governments turned a blind eye to the environmental impact of the antibiotics, antiparasitic drugs, anti-foulants and disinfectants required to produce food in such an intensive manner. And no one bothered too much about the huge volumes of ammonia and other waste products released untreated into the sea.
Now, late in the day, Scottish ministers have woken up to the dangers. As the finger is pointed at intensively farmed salmon for the spread of such marine diseases as sea lice, amnesic shellfish poisoning and infectious salmon anaemia, it has become impossible to ignore the issue. New guidance from the Scottish executive rules out new fish farms on the north and east coasts of Scotland, while requiring that expansion elsewhere must demonstrably improve the environment. This is not quite a moratorium on expansion, but it is a welcome start to cleaning up the mess that intensive farming has made of the fishing industry. The rest of the United Kingdom should follow suit, with similar restrictions.
However, the next stage must be to recognise that the whole strategy of pursuing mass production over quality has been a mistake that threatens to besmirch the name of British fish-farming in the same way as BSE has destroyed the image of British beef. Throughout the BSE crisis, Scotland managed to salvage something of its image by promoting its own specialist, disease-free herds. In short, it has traded on its reputation for quality, a tactic that the rest of the industry is belatedly beginning to copy.
Scotland should learn from its land farmers and also lead the way with fast and radical change in its fish-farming methods. As pioneered in Orkney, they must be clean and organic. Otherwise salmon can never be expected to return to the top tables.