The Scottish Government is being urged to ban thermic delicing machines at salmon farms as Norway warns of a planned phase-out on animal welfare grounds.

The machines expose farmed fish to high water temperatures, to rid them of sea lice without using chemicals.

However, new research for the Norwegian Food Safety Authority, by the Norwegian Veterinary Institute and the Institute of Marine Research, has concluded that salmon suffer pain in the hot water machines.

A spokesman for the authority said:  “The Norwegian Food Safety Authority therefore believes the method of using water from and including 28 degrees C must be phased out over two years, unless new knowledge proves that it can be used in a well-justified manner.

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“It is known that hot water treatment involves the risk of farmed fish being injured or dying. In recent years the Norwegian Food Safety Authority has received many reports of such cases.”

Zoologist Susanna Lybæk, scientific adviser for the Norwegian Animal Protection Alliance, said: “The recommended treatment temperature is 28-34C, which causes pain and panic in the salmon.”

And Miss Lybæk claimed: “The machines can be compared to torture chambers for salmon and should never have been allowed for use in the first place.”

Now protest group Scottish Salmon Watch has written to Scottish Ministers calling for a ban in this country, claiming the practice breaches the Animal Health and Welfare (Scotland) Act 2006.

Don Staniford, director of Scottish Salmon Watch, said the latest mortality data on Scottish salmon farms, published by the Scottish Government’s Fish Health Inspectorate, lists dozens of cases involving the Thermolicer, Hydrolicer and other mechanical treatments.

He added: “When people think of Scottish salmon they think of majestic wild creatures leaping up waterfalls – not of factory farmed fish crammed in cages and heated in horrific washing machines called thermolicers to rid them of parasitic sea lice.”

However, a spokesman for the Scottish Salmon Producers Organisation (SSPO) said good progress was being made in the fight against sea lice, but a range of prevention and treatment options was essential.

The SSPO spokesman added: “Over the last few years the Scottish salmon farming sector’s approach to sea lice management, of pursuing prevention over cure, has made significant progress.

Data, published monthly by the SSPO shows that sea lice levels on farms are at their lowest levels for six years.

“This achievement is due to the sector’s integrated approach to fish health and welfare.

“Hydrolicers and thermolicer are among a number of control measures that can be deployed and offer an effective way to clear fish of sea lice using water rather than with medicines.”

The RSPCA run an Assured Scheme that almost 70 per cent of Scottish salmon farms are signed up to, but the 96-page scheme document states that the RSPCA is not responsible for approving equipment.

READ MORE: Benefits of modern face of salmon farming 

An RSPCA spokeswoman said: “The thermolicer is a relatively new technology and, as such, decisions regarding its efficacy and potential welfare impact on the fish are exercised with caution in the absence of a satisfactory amount of evidence.”

“However, given the current severity of the sea lice problem in some areas, and the associated welfare concerns, the lice clearance rate offered by mechanical removal methods is an effective treatment. 

She added: “At present, it is often used where other treatments have not been working effectively. Whilst it is a robust process, the alternative would be to leave the fish untreated, which in welfare terms would be unacceptable.”

Mark Ruskell, the Scottish Green Party’s spokesman on climate, energy, environment, food and farming, said there was a lack of investment, from the highly profitable salmon farming industry, in designing fish farming systems which didn’t allow lice in.

Mr Ruskell said: “We need to be designing out the sealice problem from fishfarming in Scotland.

“In Norway if you want to expand your fish farm, or you want to open up a new fish farm, then you have to bring forward new innovation and technology.
“They have closed content fish farms at sea, they remove the interaction between wild fish and farmed fish.

“The problem is that this is a big welfare issue. If they are using heat treatment they are avoiding chemicals, but there is a welfare issue there. If they are allowing sea lice to proliferate, that is a big welfare issue for the farmed fish but also for the wild fish as well.“

It’s a problem that we don’t need to have if we move to closed container systems. Our regulations are weak compared to Norway which is driving innovative solutions.

If you make the regulations bar very, very high, and it’s a very profitable industry, the industry will move to reach the bar, if you keep the regulations low, people will keep it that way. With old open pen technology, sea lice can move in, it’s a dirty way of doing it.”

Mr Ruskell added: “The Scottish Aquaculture Institution are doing incredible work, we do have the know-how to design these things.

“The Norwegians set the bar high with innovation and the industry jumps to it. The price of salmon is going up year after year, this is a hugely profitable industry.”

A Scottish Government spokesperson said: “We regard animal welfare as of paramount importance. Marine Scotland’s inspectors are responsible for enforcing fish health legislation, and will report cases of poor welfare to the veterinarians in the Animal and Plant Health Agency, who are responsible for enforcing welfare legislation and will fully investigate any welfare complaints.”

“We expect salmon producers to work with us to help deliver sustainable growth for the sector, working within appropriate regulatory frameworks which minimise and address environmental impacts.” 

The spokesperson added that the Animal Health and Welfare (Scotland) Act 2006 places a duty of care on those with responsibility for farmed animals.  `