The Hidden Costs of Salmon

Salmon are naturally programmed to swim hundreds of miles, moving downstream from their birthplaces in British rivers to the open ocean, and then back – leaping upstream in the rivers – to spawn, reports the Independent.

The news agency says that in fish farms, their complex life cycle is artificially managed by man. Despite their extraordinary journey in the open sea, the fish are kept in 100-ft wide pens. Some escape and infect their wild cousins with lice.

To answer the critics, some British supermarkets have begun to insist on their salmon being produced to higher standards. This summer Marks & Spencer became the first retailer to switch its entire range of farmed salmon to the Freedom Food scheme run by the RSPCA. Sainsbury's has also introduced Freedom Food salmon as part of its pitch to middle-market gourmands.

Both companies are vaunting their newly accredited salmon as evidence that they take animal welfare seriously; that their fish is virtuous. Five million fish a year will have their lives improved as a result of the conversion to RSPCA standards.

But just how much better is fish with the Freedom Food label than ordinary salmon – and, in any case, should we be eating farmed salmon at all? Asks the Independent

To start with, we need to look at the reality of Britain's most popular fish. The overwhelming likelihood is that unless your salmon was sold as "wild", it has been farmed, perhaps in Scotland, but quite possibly in Norway or Chile, both big players in the industry.

According to the RSPCA and Compassion in World Farming, fish farmers have traditionally paid little attention to the welfare of their silvery charges.

Environmentalists have complained that salmon farming is denuding the sea of the smaller wild fish fed to the carnivorous salmon. By the time it is harvested from a Scottish loch or Norwegian fjord, a salmon will have consumed many times its final weight in sand eels or whiting.