Fish farming, one of the fastest growing areas of animal food production, also known as pisciculture is the commercial process of raising fish in tanks or enclosures like fishponds, usually for food. Fish farming is the primary form of aquaculture, while the other processes may fall under mariculture.

There are a variety of species of fish used in aquaculture that are farmed in both seawater and freshwater. These fish are produced in a varied range of systems from ‘closed systems’ where the water is artificially re-circulated, to ‘open systems’ where the fish are controlled in more natural bodies of water like a sea enclosure or pond. The most widely farmed species include salmon, tilapia, carp and catfish. The increasing demand for fish and fish protein has led to extensive overfishing in wild fisheries, where China provides 62% of the world’s farmed fish. According to the United Nations Food and Agriculture Organisation, about 32% of world fish stocks are overexploited, depleted or recovering and in need of urgent rebuilding.


To get a better understanding of the key issues involved in the welfare of farmed fish, we believe it’s important to be aware of the farming process.

The most commonly farmed fish species in the UK is the Atlantic salmon, with farms predominantly located in the Scottish Highlands, which includes freshwater and seawater stages to their lives. The farming of carnivorous fish like salmon does not always ease the pressure on wild fisheries.

At the production stage, fertilised salmon eggs are generally grown in trays where the eggs hatch into ‘alevins’ or ‘yolk sac fry’. At this stage, the eggs spend time on the bottom of their trays until their yolk sac has been absorbed; after which they start to rise up into the water column as ‘first feeding fry’.

Once the eggs reach this stage they are then transferred to freshwater lochs or larger tanks where they spend a considerable amount of time in the freshwater before they are ready to go to sea.

At some point during their growth phase certain physiological and external indicators trigger a transformation in the behaviour and appearance of young salmon, which means the young fish are ready to go to sea. This process is called ‘smoltification’, during which the fish are reared in seawater enclosures for the next one to two years. Once the fish have reached the required weight, they are then netted or pumped out of their enclosure and slaughtered.


There are a number of key issues involved in the welfare of farmed fish:

Transportation is one of the key issues as although fish can be transported in a number of ways, they are usually transported by boat, road or helicopter. However, whatever the mode of transport, it can be stressful for the fish, especially at the time of loading and unloading.

It is also vital to maintain the correct water quality (pH, oxygen, temperature etc.) for the entire length of the journey and delays and emergencies have to be factored-in to ensure that the water quality is maintained throughout. The quality of the water hugely affects the welfare of the fish, as different species survive better in different environments. High carbon dioxide levels and water temperatures also have an impact of the welfare of the fish. For instance, an increase in the temperature of the water when the fish are still small can help them grow faster, but if the fish grow too fast at this stage, then it could result in spinal deformities.

Sometimes farmed fish are also handled at times of vaccinations or when they are being graded according to their sizes. It is therefore crucial to keep the handling to a minimum, as it can be stressful for the fish, especially when they are taken out of the water. Also, the use of antibiotics can create drug-resistant strains of diseases that can harm wildlife populations and even humans that eat the farmed fish.

When it comes to stocking fish, while some fish prefer lower stocking densities, there are some fish that seem to prefer a higher stocking density. But what is ‘stocking density’? It is the weight of fish kept in a given volume of water. So how does this affect the fish? On its own, the stocking density isn’t necessarily one of the most important issues affecting fish welfare. But it is worth noting that when stocking densities are too low, they can cause certain species of fish to become territorial and aggressive towards each other. And, high stocking densities lead to a significant amount of pollution from fish excrement and uneaten food, which in turn leads to poor quality of water that is high in ammonia and low in oxygen.

Another key welfare issue affecting fish is the number of slaughter methods that are used in aquaculture. There are a number of methods used that are unacceptable on animal welfare grounds, such as the use of carbon dioxide, suffocation in air or on ice, or bleeding the fish without stunning. In the US, as with many other countries, there are no regulations to ensure the humane treatment of fish. Apparently, percussive stunning followed by bleeding is the only slaughter method that is acceptable in terms of animal welfare.

A significant issue of fish farms is that they often depend on wild fish species lower in the food chain, like anchovies, to feed the larger, carnivorous farmed species. Farmed carnivorous fish are usually fed fishmeal and fish oil extracted from wild forage fish. Did you know that it could take up to five pounds of smaller fish to produce one pound of fish like sea bass or salmon? Overfishing of these smaller ‘forage’ fish has repercussions throughout the ocean ecosystem. On the whole, fish farms can severely damage ecosystems in the form of diseases, pollutants and invasive species, and the damage varies depending on where the farm is located, the species of fish, the size of the production, and how it is raised and fed.


When it comes to food, local, organic and non-GMO labels direct us toward food choices that align with our ethics. But how can these notions be translated to food that’s grown in the water and not on land?

Grocery store labels for farmed fish usually specify the country they were farmed in, but nothing to indicate how they were farmed. And the reason is that there isn’t anything ‘sustainable’ yet about farmed fish worth making a label for.

Although aquaculture has the potential to become a sustainable form of aquaculture, the number of eco-friendly fish farmers is not high enough to compete with the profit-minded producers.

However, there now are a few certifying bodies that provide third-party verification for aquaculture producers looking to pursue the sustainable route. The European Union established organic aquaculture guidelines in 2009 and Canada unveiled its national organic certification program for fish in 2012, but the USDA has yet to follow suit. There are quite a few labels that indicate sustainable-farmed fish showing up in grocery stores, though it’s commonly found on product labels specifically in Europe, mostly in the frozen seafood product aisles and not at the fresh fish counters.

Greenpeace seeks to guarantee clean and healthy oceans for the future, alongside working to improve the standards of international seafood trade.


So, what can you do to help?

  • Choose higher welfare – If you are concerned about fish welfare and if you eat fish like trout or salmon, then look for products that carry the RSPCA Assured logo (previously known as Freedom Food). This is the RSPCA’s farm assurance and food labelling scheme that aims to warrant that animals reared, handled, transported and slaughtered are done so in accordance with the strict RSPCA welfare standards.

By choosing higher welfare products, you are challenging and questioning the sustainability of the products, thus challenging the retailers and increasing the demand for supermarkets to stock higher welfare products. And by doing this, you would be encouraging more farmers to improve their farming practices, thus benefiting more farm animals.

  • Research – The Greenpeace report, ‘Challenging the aquaculture industry on sustainability, offers information to the fish farming industry on becoming sustainable, and provides guidelines and standards to to seafood suppliers and retailers on how to ensure they only buy aquaculture products from sustainable practices.

You can also check out to learn more about what you can do and also to ensure that you are choosing sustainably farmed seafood.

  • Share this article and important information – Help raise awareness by sharing information and encouraging your family and friend to learn more about the welfare issues affecting farmed fish and how it not only affects our ecosystems, but has a huge impact on our health too.



Join the Buzz . . .
I agree to have my personal information transfered to MailChimp ( more information )
By signing-up to our newsletter you are opting-in to receive emails that may include company news and updates, related product or service information, informative emails, brand features and promotions on all things ethical, natural, organic and green.
We respect your privacy. Your email address will not be sold or shared with any third party. If you change your mind, you are free to 'unsubscribe' at anytime via the link at the bottom of our emails.