Hooked on eating fish? Here are the downsides!

Fish can feel fear, anxiety and pain. Many are killed by suffocation or immersion in toxic water.

I love fish… On my plate, or even better, in my mouth! But that’s as far as the love goes. Besides that they are quite stupid, have a one-second memory and they certainly do not feel pain. The struggling you see when they are caught are just reflexes. There is nothing more to them! Or is there?

Yes, there is! Fish are not that simple actually. Therefore, I want to share my main objections against eating fish. For the sake of illustration, I will mainly focus on salmon. 


There is scientific evidence suggesting that fish are sentient.1 According to Donald M. Broom, professor emeritus of Animal Welfare, this means they are aware of themselves and their surroundings, and they have the capacity of cognitive processing. Therefore, they can experience feelings such as fear, anxiety, anger and pain. Consequently, they can suffer.2

Suffering from pain

For those of us who have been led to believe that fish only show reflexes, here’s a reality check: fish do feel pain and suffer from injury, and this is slowly becoming common knowledge.

According to Compassion in World Farming (CIWF), the problem with sea lice with farmed salmon is out of control. It can cause painful wounds which can lead to infections, reduction of growth, stress, and even death.3 Figure 1 shows a salmon with sea lice.

Furthermore, aggressiveness can lead to physical injury. Young salmon for instance tend to display territorial and aggressive behaviours during their transition towards adulthood4. Confined fish under attack have insufficient opportunity to avoid the aggressor. This can result in stress and potential injury, which in their turn can lead to pain and infections. Fin rot is one example of a wound that can be inflicted. Examples of fin rot are, splitting of rays and severe loss, erosion or abnormal growth of fin tissue.5

Inability to display normal behaviours

Most farmed fish cannot display normal behaviours, which can lead to distress. Adult salmon for instance, will school together and swim in structured groups. Under natural circumstances they migrate and swim over 9.000 kilometers, following their instinct to feed and grow in the sea and then reproduce in the rivers where they come from. In confinement, they are not able to fulfill this natural behavioural need.

Although The Royal Society of the Prevention of Cruelty to Animals has published welfare standards for farmed Atlantic salmon, surprisingly they don’t give guidance in allowing salmon to perform natural behaviours.6 Neither does the Aquaculture Stewardschip Council (ASC). Their principles address health problems arising from diseases and parasites, but not the need to perform natural behaviours.7 This is strange to say the least, because fish farmers can get ASC certified. As a consumer you might rely on such labels to select animal-friendly products.

Cruel slaughter techniques

Lastly, let’s look at various slaughter techniques. Methods which are considered inhumane by the World Organisation for Animal Health are still being used by most European Union member states, despite the key principle that animals should be spared from pain, distress and suffering during killing-practices whenever that can be avoided.8

Non-humane techniques are, for instance, suffocation in air or ice slurry, as illustrated in figure 2. Now you might think fish will die quickly and suffering will be limited to minutes. Well, horrifying as it is, it can take several hours before they die, depending on their species.

Another inhumane method to choke fish is immersion in water saturated with carbon dioxide gas (CO₂), in which it can take several minutes before fish lose consciousness.9

Fish can also be decapitated. ‘Instant death’, you might think. Now don’t be shocked: European eel show brain function 30 minutes after decapitation and signs of live up to 8 hours.

Call for attention

This brief overview showed there are several welfare issues to consider before you think about eating fish, like health problems, inter-species aggressiveness, injuries, lack of opportunities to display natural behaviours and inhumane slaughter techniques.

Each fish being eaten means one individual had suffered. Therefore, I would like to conclude with this call for attention to all fish consumers: be aware of the choices you make as you might, unintentionally, contribute to their suffering.

Heard enough? Made up your mind never to eat fish again? Good for you and for the fish!

Need more evidence? Please see this inspiring videoclip Rethink Fish or go straight to Compassion in World Farming or Improving Farmed Fish Welfare.

  1. K.P. Chandroo, I.J.H. Duncan, R.D. Moccia, ‘Can fish suffer?: perspectives on sentience, pain, fear and stress,’ Applied Animal Behaviour Science 86 (2004) 225-250 ↩︎
  2. D.M. Broom, Sentience and Animal Welfare (Cab International 2014) ↩︎
  3. Underwater cages, parasites and dead fish: why a moratorium on Scottish salmon farming expansion is imperative,’ Compassion in World Farming (2021) ↩︎
  4. C. Noble, K. Gismervik, M.H. Iversen, J. Kolarevic, J. Nilsson, L.H. Stien, J.F. Turnbull (eds.), Welfare Indicators for farmed Atlantic salmon: tools for assessing fish welfare (Nofima 2018) ↩︎
  5. J.F. Turnbull, C.E. Adams, R.H. Richards, D.A. Robertson, D.A., ‘Attack site and resultant damage during aggressive encounters in Atlantic salmon (Salmo salar L.) parr,’ Aquaculture 159 (1998) 345-353 ↩︎
  6. RSPCA welfare standards for farmed Atlantic salmon,’ Royal Society for the Prevention of Cruelty to Animals (2021) ↩︎
  7. ASC Salmon Standard,’ Aquaculture Stewardship Council (2012) ↩︎
  8. Compassion in World Farming, The welfare of farmed fish during slaughter in the European Union (2018) ↩︎
  9. P.J. Ashley, ‘Fish welfare: Current issues in aquaculture,’ Applied Animal Behaviour Science 104 (2007) 199-235 ↩︎