Fish health & welfare

Ensuring the health and welfare of the fish in our care is central to everything we do at Grieg. Our fish health specialists and veterinarians act with integrity to ensure the best possible fish health outcomes even in complex biological and environmental conditions. We fulfil our responsibilities to protect both our fish and the environment by creating bespoke fish health management plans. You can learn more about this important work here.

Maintaining high standards of fish health and welfare is a top priority for Grieg Seafood Shetland. We acknowledge our ethical obligations to ensure our fish do not suffer from stress, pain or sickness, and that the highest possible number of fish thrive, grow normally, and survive to the end of their life cycle. We take a proactive and preventative approach to our fish health challenges, but we do step in to administer treatments if it becomes necessary. From a business perspective, we are incentivised and fully committed to ensuring good fish health and welfare, as it is one of the most important factors for us in ensuring good growth rates and premium quality salmon at harvest.


Fish welfare is about ensuring our fish live with as little stress or suffering as possible. Grieg Seafood identifies areas of potential stress for fish, such as transportation, handling, or providing certain treatments. To address this, we centre our procedures on ensuring that fish are exposed to the least amount of stress for as little time as possible. Our fish will never be subjected to stressful treatments unless fish health specialists or veterinarians believe that the fish are strong enough to undergo the treatment successfully. Grieg Seafood Shetland is assured in line with RSPCA guidelines on animal welfare. For instance, our salmon must be stunned and killed within 15 seconds after leaving seawater to minimise suffering and stress. Our regular seawater pens are at least 98.5% water and only 1.5% fish in order to provide the salmon with plenty of space to live and grow comfortably and healthily.


When it comes to fish health, we have a complete approach to preventing and treating diseases. We use salmon roe which possesses qualities to suit the conditions of our different locations, meaning that the fish grown for Grieg Seafood Shetland were specifically chosen for the challenges of our local environment. All Grieg Seafood sites vary in terms of the biological and environmental challenges found in the natural habitat, and that’s why we develop tailor-made regional fish health plans to adapt to these challenges. Feeding programmes are adjusted at changed to suit the different stages of the salmon lifecycle. Ensuring our fish are provided with excellent nutrition is a key step in optimising health and welfare. Our employees are trained to high standards, benefitting from ongoing fish health and welfare training with additional refresher courses being held every 3-5 years minimum. We cooperate fully with relevant agencies and other stakeholders across the sector in order to maximise our fish health improvement efforts with every opportunity.


Diseases, whether fungal, bacterial, viral or parasitic, can impact the welfare of our fish health and populations. We take disease outbreaks extremely seriously and act quickly and proportionately to deal with the first signs of any potential outbreak. We believe that prevention is always better than cure, and so we always continue to strive for healthy environmental and biological conditions. We implement preventative measures for disease control such as: compulsory fish vaccinations; regular health inspections by specialists; removing dead or diseased fish; and strict policies on the transfer of fish between boats and sites. We conduct extensive environmental monitoring. Factors such as temperature, oxygen levels, and water quality can have major impacts on our fish health outcomes.

Treating our Fish

Unfortunately, despite our best efforts, sometimes we cannot prevent disease outbreaks. We have a very strict policy on the use of antibiotics. Grieg Seafood aims to completely avoid the use of antibiotics and they are only to be used when absolutely necessary. If they are required, then their usage is subject to adequate risk assessments and are only used on smaller salmon to ensure harvested salmon contain no residues. Any prescription of antibiotics can only be done by certified fish health specialists and approved by senior managers to eliminate any risk of misuse. Grieg Seafood Shetland doesn’t use any of the antibiotics listed on the UK Highest Priority Critically Important Antibiotics.

Continuing to Improve Survival

Grieg Seafood has a survival target of at least 93%. In recent years Grieg Seafood Shetland has faced very challenging biological conditions in our sea sites which have negatively impacted our survival rates. We admit, we’re not happy with our current results and are still trying to reach that target. We don’t make excuses; our current mortality levels are unacceptable and that’s why we are always looking to improve our current procedures, for example we’ve made improvements to our vaccination program and invested in freshwater treatment to control both gill health and sea lice.

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