University of East Anglia claims farmed salmon should be sterilised

Genetically different captive salmon often escape, Professor Matt Gage from the University of East Anglia claimed. Farmed fish are less adept at dealing with predators, a trait that could hit wild populations, he told BBC News.

However, salmon farmers say escaped fish offer no threat because they have almost no chance of survival. They say sterilisation is economically unviable.

Chief executive of the Scottish Salmon Producers' Organisation, Scott Landsburg,told BBC News that effective containment of fish is a fundamental part of good fish farming.

"The industry makes huge efforts to improve containment standards.

"The survival rate of farmed salmon in the wild is virtually zero.

"There is no evidence that escaped fish have created any actual problems whatsoever for wild salmon.

"All the supposed threats are theoretical, and unfounded," he told BBC News