Millions Of Farmed Salmon And Trout Killed In UK Fish Farms; No Actions Taken Against Companies

[hatrack]

Millions of fish deaths caused by accidental poisoning and suffocation on Scottish salmon farms have been revealed after the inspection agency was forced to share its reports. The UK government’s Animal and Plant Health Agency (APHA) had refused to release inspection reports, claiming it would cause “significant detriment” to companies, including to their reputations.

However, the Information Commissioner’s Office (ICO) ruled there were no valid grounds to withhold the information, a decision the campaign group Animal Equality UK hailed as a “watershed moment for public transparency”. The ICO’s decision has led to the release of some of APHA’s inspection reports documenting details of the scale and cause of deaths on some farms.

One recorded that more than 100,000 fish suffocated at an on-land salmon farm operated by Scotland’s largest salmon farming company, Mowi, in 2021 after a worker left them unattended and their access to oxygen ceased. In a separate incident at the same site in the same month, a buildup of hydrogen sulphide killed more than 1 million fish in 10 hours. APHA took no enforcement action. Another report states that at a site operated by Bakkafrost certified by the RSPCA, 600,000 fish died from hydrogen sulphide buildup in 2022. The problem recurred months later on an even larger scale, killing more than 1.5 million fish. Again, no enforcement action followed.

EDIT

Animal Equality has published footage that it says was filmed at a Scottish salmon farm operated by Scottish Sea Farms in March, in an effort to push APHA to release more recent inspection reports. The charity says the video was taken at the Fiunary farm and shows salmon suffering from blindness, open wounds, severe sea lice infestations and missing noses. Scottish Sea Farms supplies salmon to Marks & Spencer and Fiunary is known to provide salmon to Co-op.

EDIT

https://www.theguardian.com/environment/2026/may/26/millions-of-salmon-deaths-scottish-farms-apha-ico

[harumph]

1. Apparently H2S is formed in the fish waste at the bottom of the tank in RAS.

Managing H2S is then primarily making sure the fish waste is removed before anaerobic activity can produce H2S it at toxic levels. I would hazard a guess that something like floating vac systems are used. I don't think anyone has figured out an efficient way to architect RAS that handles (degrades) fish waste passively without H2S emissions - i.e., without requiring manual removal. In the cases cited, it seems pretty clear they weren't minding the farm.