​Five facts about fish farming

A salmon above some water.

Have you ever wondered what life is like for a fish? You might think it would be pretty cool to have the freedom to swim for miles across the vast expanse of sea, but that’s a far cry from the lives of farmed fishes*. When you next see a packet of salmon on the supermarket shelf or smoked salmon on a restaurant menu, spare a thought for the individuals farmed for these products. 

1. Fishes feel

Fishes certainly have feelings, both physical and emotional. They can experience both pain and stress. Fishes are recognised as sentient under New Zealand law, which means they are known to experience a range of sensations and emotions, both positive and negative. However, the way they are treated on fish farms so often seems to ignore this sentience. 

A sea cage on a New Zealand fish-farm. It sits above the water where you can se the top of the nets that go beneath the water.
The surface of a salmon farm

2. They are trapped in cages

In Aotearoa, the fish species farmed is called King Salmon. They are a migratory species.  Born in freshwater, they migrate and spend most of their life at sea before returning to freshwater to spawn. Naturally they travel thousands of kilometres in their lives, but on fish-farms they are trapped in floating cages, crowded in with thousands of other individuals. Their natural instinct to migrate is blocked. Instead, they swim in circles around the cage, rubbing against the mesh and each other.

A group of salmon swimming.

3. Farmed salmon can suffer depression

Did you know that fishes can get depressed? Up to a quarter of farmed salmon are found floating, listlessly at the surface of the water, their growth stunted. The industry calls them ‘drop outs’. A study on farmed Atlantic Salmon in sea cages in Norway showed that the ‘drop out’ fishes’ brain chemistry and behaviour was almost identical to people that are highly stressed and depressed.

A salmon lying on their side on a dark background. Their throat appears cut.

4. High mortality on fish-farms

Farmed fishes are prone to a range of health problems and some die before slaughter from the horrible conditions inside fish-farm cages. This is being made worse here in Aotearoa by climate change warming the sea temperature above the range that salmon will survive in. While the exact number of fish dying is not disclosed, New Zealand has a high mortality rate by international standards. According to a Ministry for Primary Industries report, NZ King Salmon, (the biggest salmon producer), expects a mortality rate of approximately one quarter. That’s a huge number of individuals who can’t survive the factory-farm environment. 

A pile of small fishes

5. Blue loss

Fish farming is often promoted as the solution to overfishing, but a study by the Aquatic Life Institute has found that up to half of all animals caught at sea are fed to fish on farms. A term has been coined for this, ‘blue loss’.

Salmon are a carnivorous species. They are fed a range of foods which includes other fishes taken from wild populations. This is why, fish-farming adds to the depletion of wild fish numbers, rather than helping provide more food for people.

So fish farming certainly isn’t a solution to current food problems, and just like other intensively farmed animals, fishes are suffering miserable lives.

*The term ‘fishes’ rather than ‘fish’ is increasingly being adopted by the animal advocacy movement to recognise and emphasize the individuality of the intelligent, feeling individuals we are describing. (The fish-farming industry only measures fishes in tonnes, rather than numbers of individuals.) 

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