The Ethics of Eating Fish

We often view fish and other marine animals as having short memories and lacking consciousness, so why should we care about them? After all, are they even sentient, or do they feel pain?

Marine animals are by far the animals that we kill the most of, to put it into perspective we kill somewhere around 60 billion land animals every year, however it is estimated that we kill somewhere in the region of 1 - 2.7 trillion marine animals in the same period.

So do fish feel pain?

The nervous systems of fish are similar enough to those of birds and mammals to show that they do feel pain and when fish experience something that would cause other animals physical pain, they behave in ways suggestive of suffering, and the change in behaviour may last several hours. Fish will learn to avoid unpleasant experiences, like electric shocks. And painkillers reduce the symptoms of pain that they would otherwise show.

Even crustaceans such as prawns have shown this by responding to acid being brushed on their antennae, showing complex and prolonged movements that diminished when local anaesthetic was applied beforehand.

Furthermore, a scientific panel for the European Union concluded that the evidence shows that fish do feel pain. Ultimately, it is easier for us to recognise suffering in an animal such as pigs, who can vocalise their pain. But for marine animals, their suffering may be silent to us, but it exists for them nonetheless.

Fish have also been shown to have stress responses, with their cortisol levels, a hormone that is released during times of stress, becoming raised when they were taken out of water and placed in a bucket.

When it comes to their intelligence, Australian Biologist Culum Brown states that, based on his years of research into fish behaviour and learning, "They're just not any less intelligent or sophisticated than terrestrial animals. That idea is a total myth.”

““They’re just not any less intelligent or sophisticated than terrestrial animals. That idea is a total myth.””

— Australian Biologist Culum Brown

Are fish intelligent, and how are they farmed?

Fish can be taught how to evade a trap and remember it a year later. Fish can learn from each other, recognise other fish they've spent time with previously, know their place within fish social hierarchies, and remember complex maps of their surroundings.

Fish also work together with different species of fish and show cooperation and trust. With fish remembering which other fish were cooperative or uncooperative.

The fact that fish can create alliances, formulate rules and engage in acts of mutualism, as well as alter their behaviours to maximise their own individual success, demonstrates how highly intelligent and cognitively complicated they are.

Yet even though these animals are highly intelligent, can show emotions and can feel pain, we cause huge amounts of suffering and ultimately death to incomprehensible numbers every single year.

Impaling live bait on hooks is a common commercial practice: for example, longline fishing uses hundreds or even thousands of hooks on a single line that may be 50-100km long. When fish take the bait, they are likely to remain caught for many hours before the line is hauled in.

Fish caught in the wild are dumped on fishing boats and will die either by suffocating, being crushed because of the weight of all the other fish on top of them, or through their internal organs rupturing from the rapid pressure changes during the ascent.

Another method of catching wild fish involves gill nets – walls of fine netting in which fish become snared, often by the gills. They may suffocate in the net, because, with their gills constricted, they cannot breathe. If not, they may remain trapped for many hours before the nets are pulled in.

The fish that are still alive when they begin being processed will then die through a combination of suffocation and evisceration, which is where the animals are gutted alive.

One Dutch study found that it took 55 minutes to 4 hours for various species of fish to become insensible during asphyxiation and some fish can remain conscious for 20–40 minutes after being gutted.

Aqua farming, which is the equivalent of factory farming for fish and is responsible for nearly half of all fish consumed worldwide each year, involves fish spending their entire lives in underwater enclosures, normally either in sea cages or concrete tanks

Due to the overcrowding, the fish are more susceptible to disease and suffer from stress and physical injuries such as fin damage, or spinal deformity, as well as parasitic infections. It is not uncommon for many of the fish to die in the farms. Because of this antibiotic use is prevalent within fish farms.

Fish are regularly handled roughly on aqua farms and those that are deemed too sick are taken out of the tanks and often beaten to death.

Farmed fish are slaughtered by a range of methods, such as gassing with carbon dioxide or cutting their gills without stunning. Some fish are simply left to suffocate in air or on ice, which causes them significant suffering as they try to get the ice out of their gills, they are also often processed while still alive, as even though the cold may paralyse them, scientific studies have shown that they still remain conscious and can feel pain and stress. Alternatively some are killed by being electrically stunned or are hit over the head, before then being bled out.

It is also worth mentioning that many farmed fish, such as salmon and sea bass are carnivorous, meaning they are fed wild caught fish, and so buying farmed fish also contributes to the suffering of wild fish as well.

Ultimately, fish are sentient animals who feel pain and suffer, and in the case of both farmed fish and wild caught fish, not only do these animals suffer, but they have their lives taken from them needlessly. So perhaps it is time for us to change how we view marine animals, to understand that how we view fish is based on outdated opinions, and to question whether they can suffer, or feel pain, is to question what has proven by science.