Salmon farmers are ‘torturing’ porpoises and dolphins with high-pitched noises, campaigners warn

Porpoises, dolphins and whales are under threat from salmon farmers who use high-pitched noises to protect their stock, campaigners have said.

Underwater devices are used to scare off seals that can each eat up to 15lb of fish a day. But the equipment has been branded ‘sonic torture’ by campaigners who are calling for a ban.

David Nairn, from the Clyde Porpoise Marine Mammal Project, said: ‘Acoustic deterrent devices can cause temporary and permanent hearing damage to porpoises and other cetaceans. 

The noise can and does displace them from foraging and nursery habitats and generally disturbs and harasses the animals.’

Mr Nairn, who wants farmers to use netting instead, added: ‘Noise pollution increases stress levels and makes animals more susceptible to disease.’

Around £1 billion of farmed salmon is sold every year, with most of the industry based in Scotland’s sea lochs and coastal waters.

Conservationists believe the acoustic devices may already be illegal as it is an offence to ‘deliberately or recklessly disturb, harass or injure any porpoise, dolphin or whale’.

The Scottish Salmon Producers Organisation said farmers are required by law to protect their fish and expect the acoustic devices to remain as one of the key measures to deter predators.