A Meridian Salmon Group spokesperson said: “We can confirm that our Ness of Copister farming site on Yell, Shetland, suffered serious damage as a result of the sustained, severe storms that have hit the region.
“Gale force winds and large swells caused a major failure of the mooring equipment which subsequently damaged a number of the eight cages on the site.
“Staff – including diving teams – have been working in very demanding conditions during the continued extreme weather to carry out repair and salvage operations and to try to assess the impact of the incident.
“There was in excess of 364,000 fish on the farm. Fish from three of the cages were safely removed during the initial salvage exercise.
“However, after weather conditions relented to allow a thorough site assessment, it has been determined that 154,569 fish were lost. All remaining fish on the site have also been removed to new locations.
“Marine Scotland has been kept fully informed of the incident.
“While it is widely accepted that we were dealing with exceptional weather conditions – local reports indicate the unrelenting gales that have battered the east coast of Yell are the worst in decades. However, losses like this are not acceptable and we will be carrying out a full review of our systems to ensure we have no similar incidents in the future.
“This will include discussions with mooring manufacturers and other mooring experts, after which, any recommendations for improvement will be implemented at the earliest opportunity.”