HIGH heat treatments used to kill-off lethal parasites in Scotland’s £2 billion-a-year salmon sector breach animal welfare standards and should not be used in Scotland, according to a leading scientist.

Fish farms use a number of techniques to deal with the sea lice which eat into the flesh of live salmon, causing serious injury and death.

The parasites, which also occur in the wild, can be dealt with through chemical treatments or the deployment of other species like lumpfish and wrasse, which eat the pests.

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However, the big-money industry – which produces Scotland’s top food export – also uses thermolicer and optilicer devices which raise water temperatures to 34C to kill the lice.

According to a range of studies, that is several degrees hotter than salmon can bear without stress or pain.

Now Dr Lynne Sneddon, the director of bioveterinary science at Liverpool University, has called on the Scottish Government to halt the use of hot water techniques at fish farms, claiming these breach regulations on the treatment of farmed animals.

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Sneddon (above), who specialises in aquatic life forms, previously proved fish have nerve endings capable of feeling pain which are “strikingly similar to those found in humans”.

In a letter to the Scottish Government, the Animal Welfare Commission and the RSPCA , she says two devices – the thermolicer and optilicer – contravene the “five freedoms” underpinning farming rules, which state that animals should be kept free from hunger, discomfort, pain and injury, fear and distress, and be able to express normal behaviour.

Sneddon wrote that the treatment methods result in “harm and poor welfare and should not be employed within the Atlantic salmon farming industry”.

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She told The National: “It’s contrary to good welfare practice.

“What happens at fish farms is hidden. People don’t know.

“They are reared intensively, have incidents of disease, and they end up in quite poor welfare and, in effect, suffering.

“If you saw a flock of sheep or herd of cows like that in a field you would be appalled. We do quite a lot of things to fish that cause them damage. There’s compelling evidence for pain in fish. Their systems are similar to those found in mammals.

“The industry has invested quite a lot of money in these treatments and I sympathise with that, but there are other methods of treatment like

hydrogen peroxide, which breaks down and has no effect on the environment.”

In March 2019 Julie Hesketh-Laird, chief executive of the Scottish Salmon Producer’s Organisation (SSPO), said the sector had spent £53.5 million on mechanical treatments like the thermolicer and hydrolicer, which uses water to dislodge lice, over the past three years, with sea lice averages at their lowest level since 2013 thanks to eradication initiatives.

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Last week its director of strategic engagement, Hamish Macdonell, said farmers had “worked hard to overcome environmental challenges” like increased water temperatures.

Those conditions can encourage sea lice numbers to increase and figures were slightly up. However, the SSPO said the sector is “continuing to successfully pursue its ‘prevention over cure’ strategy with regards to the management of sea lice, with medicinal spending falling as the increasing deployment of innovations such as cleaner fish and mechanical treatments”.

Macdonell commented: “The Scottish salmon farming sector continues to invest and innovate in the management of such challenges. Fish health and welfare will always be our members’ top priority.

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Photograph: Corin Smith Photography

“There are a number of initiatives underway to increase the number of health management tools available to Scotland’s fish farmers. These are being complemented by focused research into understanding the impacts of recent environmental challenges, the Scottish 10-year Farmed Fish Health Framework and increased sector-wide information sharing.”

But Don Staniford, director Scottish Salmon Watch, said it plans to challenge the Scottish Government “on the lawfulness of the thermolicer under animal welfare legislation”.

He went on: “The weight of scientific and damning case evidence demands an immediate ban to end the welfare nightmare.”

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And Dawn Carr, of animal rights group PETA UK which supports a thermolicer ban, said: “Animals raised for their flesh – whether on land or in water – suffer horribly and needlessly. Severe crowding and confinement on fish farms can lead to the rapid spread of gill disease, open sores, and flesh-eating lice, which fish endure all while swimming in their own diluted waste.

“Fish farming is devastating to fish and the environment, and the best way for individuals to help these sensitive animals is simply to stop eating them.”

A Scottish Government spokesperson commented: “The Scottish Government takes animal welfare very seriously, including that of farmed salmon. That is why we are supporting a research project to explore the impact of the use of thermal treatments for sea lice which is being undertaken by the Scottish Aquaculture Innovation Centre.”