AN anti-predator device with a difference has been installed by Mowi Scotland to scare off seals at its farms in the Outer Hebrides.
A life-size replica killer whale, made of fibreglass, is being deployed as a type of scarecrow, in the latest bid to keep salmon safe from predation attacks.
The whale, launched last week, also emits killer whale noises. Made in the UK, it cost about £12,000 – which doesn’t include the addition of sound, said Mowi Scotland communications director Ian Roberts.
‘It will sit about 4m below the surface and move with the current. We will review its effectiveness, and if it provides positive results will consider launching additional orcas,’ said Roberts.
While salmon farmers are allowed to shoot seals on licence, the number killed has dropped 81 per cent since 2011 and the industry’s aim is for zero shootings.
Animal welfare legislation in the US, one of the biggest export markets for Scottish salmon, will soon make it illegal to sell fish if marine mammals have been harmed during the production process.
Farmers have invested millions of pounds in anti-predator netting and acoustic deterrent devices (ADDs), and an electric fish, made by ADD manufacturer Ace Aquatec, is also now being used inside nets at some farms.
‘Hundreds of salmon can be killed by just one seal in a very short time, which can be devastating to a farmer and is also an animal welfare issue,’ said Roberts.
‘A farmer, whether on land or at sea, must be able to protect his or her stock from harm.
‘No sea farmer or river fisher wants to harm a seal. While the ability to cull a seal may be taken away from a fish farmer, we do expect our government to responsibly manage predators that may prey on fish farms and fisheries – as is currently the case in America and provided to terrestrial farmers in the UK.
‘We use several non-lethal methods of deterring seals, including acoustics and additional protective netting.
‘Fortunately, our interactions with seals are relatively rare but as the population of seals continues to grow we need to be extra diligent in protecting our fish.’
He added: ‘If you’ve watched a David Attenborough documentary you will know that seals have good reason to fear killer whales.
‘We hope that this replica killer whale will look menacing enough to encourage seals to keep swimming by.’
There were earlier versions of ‘whales’ used to frighten seals. At a farm in the north of Scotland, at Loch Eriboll, independent operator Charles Marsham had a life size fibreglass killer whale constructed by a local boat builder in the mid-1990s (see Fish Farmer, May 2019).
But Marsham did not claim 100 per cent success: ‘The deterrent is visual,’ he said at the time. ‘The seal has got to see it. It has to be placed on the seals’ route toward the sea pens.’