More than 1 million farmed salmon die in Scotland’s biggest mass mortality in a decade

More than a million farmed salmon have died at Mowi Scotland’s Loch Seaforth sites, marking the largest mass mortality of farmed salmon in Scotland in a decade, reports The Guardian.

The deaths, which occurred during the standard year-and-a-half production cycle beginning in spring 2023, were attributed to rising sea temperatures and subsequent jellyfish blooms, according to Mowi.

Ben Hadfield, Chief Operating Officer of Mowi Scotland, confirmed the total number of fish deaths of 1.05 million from the two sites, known as Seaforth and Noster. He stressed that the mass mortality is “highly false and misleading” if it is linked to poor agricultural practices.

“This is caused by an unprecedented rise in sea temperatures,” he said, explaining that jellyfish stings to the eyes, skin and gills of fish can lead to health complications and death.

The disturbing data came to light through an analysis by Scotland’s Coastal Communities Network (CCN) and the NGO Free Salmon.

“This is the first time since 2014 that more than one million farmed salmon deaths have been reported during a single production cycle on a single farm,” said CCN representative John Aitchison.

He also stressed that such mass deaths could be an indication of poor animal welfare and expressed concern that larger farms could exacerbate these problems in the future.

Despite the mass mortality, Mowi maintains that the welfare of his fish remains a priority. Hadfield noted that salmon mortality in Mowi “has decreased by two-thirds this year as temperatures have normalized.”

The incident has drawn attention to welfare practices in Scotland’s salmon farming industry. The Royal Society for the Prevention of Cruelty to Animals (RSPCA), which certifies many of Mowi’s farms under the RSPCA Assured label, recently suspended three Scottish salmon farms following reports of breaches of welfare regulations.

However, an RSPCA spokesperson clarified that the jellyfish-related health issues at Mowi’s sites are beyond the supplier’s control and do not jeopardize its welfare certification.