Farmed vs. Wild Fish…What’s The Difference?


Almost everyone I know recognises the nutritional benefits that can be found in fish and other forms of seafood.  If you’re a fish lover have you thought about the journey your food has taken to get to your plate?  From nutritional value and environmental impact to sustainability and contamination, there are many things to consider when thinking about farmed vs. wild caught fish. Here’s a brief summary of each to help you make an informed decision the next time you’re feeling fishy:


Farmed Fish

Aquaculture – also known as aquafarming – refers to the farming of not just fish but also molluscs, crustaceans, and aquatic plants in an artificial environment. There are many species of fish used in aquaculture, and these are farmed in both freshwater and seawater. They are produced in a wide variety of systems, which range from closed systems, where the water is artificially re-circulated, to open systems where they are contained in more natural bodies of water, such as a pond or sea enclosure.  Farming can help take the pressure of wild stocks by providing a year-round supply.


What do Farmed Fish Eat?

According to the Marine Conservation Society, the majority of UK farmed species are fed a carnivorous diet. The feed for carnivorous fish comprises fishmeal and fish oil derived from wild caught species such including anchovy and jack mackerel.



Diseases linked to parasites and sea-lice can occur amongst farmed species which are kept in much higher stocking densities than would naturally occur in the wild.  These diseases can be minimised with the use of vaccines and various sea-lice treatment.  Unfortunately, a number of sea lice treatments are either toxic for some marine life such as crustacans or their effect on many other marine organisms is unknown


Wild-Caught Fish

This label is fairly self-explanatory.  Wild caught species come from natural bodies of water such as seas, lakes and oceans. There are several different catching methods that are used in the UK such as trawlinglong-lining and the use of different types of nets.



Trawling can be the most destructive to both the environment and the fish as large nets scrap the seabed dragging all the fish with them.  Certain types of trawling can leave tracks 10cm deep in the sea bed and can kill a huge range of species of sea life.



Involves a line of up to 30 miles containing hooks baited with live fish that are left for a day or so.  Although long-lining does not damage the seabed in the way that trawling does it is still harmful to the environment as turtles, sharks and rare marine birds are all inadvertently caught by long-lines


Gill Nets, Drift Nets & Tangle Nets

These type of nets hang in the sea like a wall and catch whatever swims into them.  While small scale gill nets can be used responsibly by inshore fishermen (especially when the mesh size is large enough to allow immature fish to swim through) large scale drift nets can be massively damaging due to unwanted species and marine creatures that get trapped.


In Conclusion…

There are lots of points to consider here.  Whatever your perspective it can be helpful to look for certification stamps to ensure the manufacture has taken the above points into consideration.  The Freedom Food Certification is the RSPCA scheme to ensure high welfare standards are implemented and maintained for farmed animals.  This, along with the Aquaculture Stewardship Council set strict requirements that encourage seafood producers to minimise the key environmental and social impacts of seafood farming.  The well-established Marine Stewardship Council (MSC) certification is used for wild fish.  To be MSC certified, fisheries are independently assessed by scientists and marine experts to ensure they meet high standards for environmentally sustainable fishing.  They also need to show good management practices to help ensure fish stocks and habitats are healthy, and fishing community livelihoods are secure.

Organic farmed fish would be my preference as these farming practices meet high environmental standards, including limits and restrictions on the use of medicines, chemicals and sea lice treatments. Feed is sourced sustainably and stocking densities are limited.  What do you think?