It said that there was a “lack of evidence” that the standards were delivering good enough animal welfare and environmental outcomes, or that this could change fast enough.

The review heard from producers, aquaculture specialists, scientists, policymakers, animal welfare specialists and campaigners, and considered a range of evidence relating to salmon welfare, environmental performance and the effectiveness of the Soil Association standards in “delivering good outcomes”.

Soil Association chief executive Helen Browning stated: “The mission behind the Soil Association and its standards is to develop and support farming systems that care for the natural world and farmed animals.

“When we started working on salmon 20 years ago, we had an aspiration for an aquaculture system that could deliver the principles of organic production in the sea. We envisioned a multi-trophic, enriched environment which could provide the resources for a good life for salmon, with minimal negative impact on other species. However, progress along these lines has been negligible. While our standards ensure lower stocking rates and prohibit the most damaging chemical treatments, the evidence suggests that welfare and environmental outcomes are not sufficient for us to continue.”

“There is a bigger research and development piece needed here which, as a charity, it is not our role to lead.”

Browning continued: “Furthermore, new welfare challenges like jellyfish blooms are emerging due to warming seas. The salmon industry is dynamic and profitable and may well be able to innovate to deal with these emerging challenges. But we were not confident that the issues were likely to be resolved within a suitable timeframe through our standards. There is a bigger research and development piece needed here which, as a charity, it is not our role to lead.

“While no farming system is perfect, the Soil Association standards set a high bar. When consumers see our logo on pack, they should be confident that organic principles are being safeguarded to the highest level possible within the constraints of a commercially viable system. This means being prepared to ask difficult questions and this is a case where we must act on the evidence when we believe we can no longer provide that assurance.”

Key findings included:

• Organic sites performed well on veterinary treatments, with the most harmful treatments banned and minimal use of the treatments that are permitted, including Deltamethrin, in the last two years.
• Analysis of publicly available data on mortality and sea lice outbreaks showed high mortality rates, which were “not significantly better than non-organic sites” in recent years.
• It also found that mortality events were often outside of the control of the sector with rising water temperatures leading to parasite outbreaks and disease. The Soil Association said there was a “lack of evidence and therefore confidence” that this was likely to change within a tenable timeframe. 
• There was concern around feed sustainability, as organic standards require producers to feed salmon as natural a diet as possible. The Soil Association was concerned this was resulting in too much reliance on wild fish stocks and the review had an ambition to progress stricter standards to prioritise marine by-products and trimmings, but challenges around these products led to a lack of confidence that this was likely to be resolved fast enough.

The Association claimed that its standards had led to improvements in both organic and non-organic salmon farming, leading to practices being rolled out across the industry. It will now work with the industry to agree a timeline for withdrawal of its logo.

According to Salmon Business, statutory organic regulations will remain in force, with the Soil Association’s certification subsidiary continuing to honour existing contracts.

A spokesperson for industry body Salmon Scotland said: “We have been assured by the UK Government that our farms will continue to be assessed against organic standards with no loss of certification. Consumers can therefore continue to buy Scottish organic salmon with confidence.”