Talking Point: Losing fish in a barrel

UK Defence Secretary Philip Hammond recently announced to the House of Commons that "low levels of radioactivity" had been detected in the cooling waters at Dounreay, following a nuclear submarine test reactor leak in 2012.

It later emerged that, not only did the MoD choose not to inform either the Scottish Government or the general public of the leak, but according to the SNP, they actually lied openly to residents, telling them it was “business as usual,” “on schedule”, and that there was “little to report” during regular meetings.

The news brought outrage from environmentalists, as well as from the Scottish Government – with Alex Salmond accusing the UK Government of disrespecting Holyrood and the people of Scotland.

In fact it is still not at all clear what convinced the MoD to drop the secrecy and make the incident public now.

The leak was small. In fact it measured zero, at a level defined by the International Energy Agency as 'below scale - of no safety significance'.

In terms of actual risk to human health, the danger was minimal, but nuclear meltdowns – like shark attacks or meteor strikes – feed into a widespread human fear, and it is easy to see how the leak drew so much attention.

Contrast this to another announcement – that 154,569 salmon have escaped from a fish farm near Shetland. As jail breaks go – this was a big and extremely embarrassing one.

Farmed salmon are typically more aggressive than their wild cousins and aside from the concern that a gang of prison-tough salmon are prowling the Atlantic bullying the locals, or considering returning to spring their friends, the escape could have serious implications for the marine ecosystem.

Millions of salmon escape from fish farms each year and biologists are increasingly concerned that they are destroying genetic traits evolved in wild populations. They breed faster than wild salmon, but are much less effective at escaping predators. Researchers estimate that around 25 per cent of wild salmon in Scotland’s western Highlands and islands are hybrids.

Trace levels of the banned pesticide DDT has also been discovered in packs of farmed salmon. Farmed fish are sprayed with chemicals to kill off parasites but their food supply can become contaminated by these chemicals, allowing DDT to get into the human food chain.

However, despite the environmental implications of 155,000 drugged up, aggressive, prison-reared salmon terrorising the Atlantic, the news of the escape will not attract much attention.

But make them radioactive and it’s a different story.