Introduction
Predators don’t change but the solutions do!
TWO images reveal how far anti-predation measures have developed over the decades.Although both inventions have the same goal, there the similarity ends! The painting of the whale was one of the early attempts to prevent seal attacks, by Marine Harvest, and it was deployed at Cairidh, Loch Ainort, on Skye in the early 1990s.
A more advanced version of this ‘technology’ was produced on a farm in the north of Scotland at Loch Eriboll, where independent operator Charles Marsham made a life size fibreglass killer whale that he used to try and scare off seals.
According to recently retired AKVA sales manager Dougie Johnson, there was great interest, particularly from Japanese journalists, in the whale at the time.
A local newspaper report from 1995 revealed that the whale was constructed by boat builder Marty Mackay. In fact, there were several whales, described as a scarecrow for seals and nicknamed the Whalley.
The Whalley was designed to be tethered underwater near salmon nets, and the trial of a wooden prototype over a six-month period in 1994 showed a dramatic and sustained drop in salmon killed by seals.
Whalleys were subsequently sold to Maine and Seattle, but Marsham did not claim 100 per cent success.
‘The deterrent is visual,’ he told reporters. ‘The seal has got to see it. It has to be placed on the seals’ route toward the sea pens.’
Fast forward to the present day, and the engineering may have advanced considerably but the predators remain stubbornly persistent.
One of Scotland’s most innovative aquaculture companies,Ace Aquatec, has reinvented the concept with its electric fish.
The innovation, which is shortlisted for the Animal Welfare Award in this month’s Scottish Aquaculture Awards, is a non-acoustic deterrent.
It is designed to look like a dead salmon and sits at the bottom of a pen.The electrodes that protrude from the ‘fish’ deliver electric shocks to seals that try to eat morts in the pen.
It attracted much interest at the Boston seafood show earlier this year, and also proved a hit at the Aqua Sur exhibition in Chile last year.
The Ace Aquatec team were taking it to the Brussels show too, where they hoped to introduce it to an even wider global market.
Sales and marketing director Mike Forbes said:‘We designed it for
people who have more restrictions on sites with acoustic devices, which is primarily the US, Canada and then Australia and New Zealand.’
Ace Aquatec has a couple of the electric fish on sites in Scotland and is currently ramping up production for the commercial systems, with units destined for New Zealand and Australia.
‘We’ve already got homes for the next ones we produce, in Scotland, where we see it as more of a complement.
‘Sites in Scotland that have used it so far have been the ones that customers find the most challenging [with predators].
‘Often, it’s been a temporary fix when there’s a particular issue on a couple of cages, or one bad site, and they just want another tool in their arsenal to avoid having to call in a marksman.
‘When we put it on a particular cage we got the morts down to zero.They saw it as a big benefit using it.’
Over the following pages we bring more news of the industry’s solutions to predation and escapes.
“When we put it on a particular cage zero” we got the morts down to