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Industry publishes salmon mortality rates

A Shetland salmon farm.
The Crown Estate owns the seabed in Scotland to the 12 miles limit.

MONTHLY mortality rates for fish in Scotland’s salmon farms have been published for the first time.

Details of around 50 farms in Shetland operated by Cooke Aquaculture, Grieg Seafood and Scottish Sea Farms are included in the reports, which were issued by the Scottish Salmon Producers Organisation (SSPO).

The average monthly mortality rate for April across the country was 1.32 per cent.

Locally the figures for April varied, with many farms having well below the average mortality rate, including some at around 0.3 per cent.

But some skewed the average figure with higher mortality as a result of environmental factors and cardiomyopathy syndrome (CMD).

Figures for cumulative mortality over a full production cycle have also been released, and after a full cycle in February a Grieg site at North Voe in Shetland had seen over 40 per cent of its stock die due to gill disease, with numbers now recovered.

A host of salmon farms in Shetland were in fallow periods at various points during the first four months of the year, meaning no figures were available.

Nationally the average mortality rate in January was 1.35 per cent, less than one per cent in February and 1.49 per cent in March.

Causes for the death of fish across Scotland included disease, treatment losses, bacterial challenges and gill health.

A public commitment to release farm-by-farm figures came from the SSPO earlier this year during a Scottish Parliament committee hearing into the environmental impact of salmon farming, although the organisation agreed at a board meeting last November to publish the data.

Scottish Government’s chief veterinary officer Sheila Voas said: “We welcome the fact that salmon farming is taking steps to be more open and transparent about the levels of mortality within the sector.

“Of course, what is most important is that we all work together to tackle mortality of any level, in any sector, to help reduce it to an absolute minimum.

The recently published 10-year Farmed Fish Health Framework for Scotland is a progressive step towards that aim, bringing together producers, government and regulators to address the big issues in aquaculture.”

SSPO chief executive Julie Hesketh-Laird said the health and welfare of salmon is “hugely important to salmon farmers”.

“This regular, voluntary publication is unparalleled and sets a precedent for transparency in business reporting. It sets a base line to show future trends and currently around two-thirds of active salmon farms have 99 per cent survival rates.”