THE SALMON farming industry has come under fire for "shocking" levels of fish deaths as it emerged they have hit record levels in Scotland due to diseases and parasites.

Official figures reveal that the amount of destroyed fish has risen by two-and-a-half times in four years with 25,737 tonnes - more than 11 million fish - being thrown away in 2017. Fifteen years ago the mortality rate was more than a fifth of the current level at 4,613 tonnes.

Campaign groups say the figures are "shameful" and that instead of doubling salmon farming production by 2030 the Scottish Government should be ordering "drastic reductions in production" before the lice and disease crisis spirals yet further out of control.

HeraldScotland:

Graeme Dey, the convener of the parliamentary environment, climate change and land reform committee in a commentary on a Holyrood inquiry into the environmental impacts of salmon farming that he and his colleagues are "concerned that the industry and regulators appear to be incapable of reducing the level of mortality".

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Salmon is Scotland’s single biggest food export – worth £600 million – and is estimated to provide nearly 2,500 jobs directly with thousands more supported by the aquaculture sector in rural and coastal communities.

But in a damning indictment of the industry, Mr Dey says in an email to Edward Mountain, the convener of the rural economy and connectivity committee that the levels would "not be considered acceptable in other livestock sectors and should not be considered to be acceptable in the salmon farming industry."

HeraldScotland:

According to the new official figures the company that suffered the biggest losses was Marine Harvest Scotland, where there were 7066 tonnes of dead fish while the Scottish Salmon Company, registered in the Channel Islands, saw 6,029 tonnes of dead fish.

Sea lice, which have been a major problem for the farmed salmon industry, feed on the skin and blood of salmon, and can weaken the health of a fish and its growth.

READ MORE: Ruth Davidson and Michael Gove unite on fishing

In October, last year, 125,000 salmon died on Marine Harvest's sites in Loch Erisort on the Isle of Lewis after being hit by the bacterium Pasturella Skyensis.

HeraldScotland:

The company then apologised to local people concerned about the smell of decay in the area and the sight of lorries carrying away dead fish.

The pathogen was believed to have taken hold at the farms at the end of August.

One theory behind the emergence of the disease was that climate change and rising ocean temperatures could be making Scottish fish farms more vulnerable to bacterial infections.

Infected salmon become very lethargic, stop eating and as the illness progresses it can prove fatal.

READ MORE: Ruth Davidson and Michael Gove unite on fishing

Campaigner Don Staniford of the newly launched Scottish Salmon Watch said the new figures had brought "shame on the Scottish salmon industry".

He said: "Scottish salmon farming's mortality rate is as shocking as it is unacceptable. A mort mountain of over 25,000 tonnes of diseased Scottish salmon is stomach-churning."

HeraldScotland:

Marine Harvest, which last month announced spending cuts in response to the rising costs of treating sea lice and disease, accepted there were issues to address.

A spokesman said: "The salmon farming industry does face challenges with mortality at sea but this is an issue we are seriously addressing. It needs to be said that some sites are more affected than others and it’s important we understand why this should be."

The Scottish Salmon Producers Organisation added: "We recognise that marine conditions are changing and bringing new challenges to fish health and environmental management that are different to those that faced the industry’s forerunners.

READ MORE: Ruth Davidson and Michael Gove unite on fishing

The sector spends around £10 million per year in research and over £50 million in new equipment and techniques to understand and manage health and environmental problems. However, we accept that progress must be better demonstrated and we are working with the support of the Scottish Government, the Scottish Environmental Protection Agency (SEPA) and scientific bodies to make better headway."

HeraldScotland:

Mr Dey in a letter to the rural economy convener last week warned there had been a "lack of progress" in tackling many key issues previously identified and "unacceptable levels of mortality persist".

He warned that Scotland was at a "critical point" in considering how salmon farming develops in a "sustainable way in relation to the environment."

The planned expansion of the industry over the next ten to 15 years will place "huge pressures on the environment", he said.

Video: The rural economy and connectivity committee launched a call for views over the crisis with the deadline for submissions on April 27

"If the current issues are not addressed this expansion will be unsustainable and may cause irrecoverable damage to the environment," he said.

"The committee is deeply concerned that the development and growth of the sector is taking place without a full understanding of the environmental impacts. The committee considers an independent assessment of the environmental sustainability of the predicted growth of the sector is necessary.

"There need to be changes to current farming practice. The industry needs to demonstrate it can effectively manage and mitigate its impacts.

"The committee is supportive of aquaculture, but further development and expansion must be on the basis of a precautionary approach and must be based on resolving the environmental problems. The status quo is not an option."