Fish are fascinating and diverse individuals, who have been around for millennia and developed some impressive skills. Some fish will use rocks to open shells, outperforming primates with their ability to learn and use tools, while others will build nests to hide their babies. Some will simply steal another fishes’ home if they take a fancy to it!
Despite research showing that fish are sentient and can experience pain and fear, they remain one of the most abused animals on the planet.
Catching fish from the wild
The number of fish stolen from the wild, to be consumed as food, is so huge that statistics don’t report on individuals, instead referring to them as a collective weight. Scientists have attempted to rectify this by using a species’ average weight to calculate that an estimated 0.97 – 2.74 trillion individuals are caught from the wild every year (importantly this does not include those killed as bycatch or the farming of fish – more on those below). There are several methods of catching fish on an industrial scale and all are indiscriminate in who, and how many, they catch.
Trawler nets are typically funnel-shaped and dragged by either a single vessel, or two vessels who drag the net between them. These nets chase fish to exhaustion and can be the size of football pitches, scooping up everything in their path. The net is then hauled up from the seafloor with devastating consequences: thousands of fish will be crushed to death in the panic, while thousands more will endure excruciating decompression which is where the sudden change from high to low pressure makes bodily gas expand, causing the stomach to balloon out of their mouths, their eyes to bulge and bubbles to form in their hearts and brains. The trawl tow can last several hours, after which nets are tipped onto the boat’s deck. Those who are still alive will start to suffocate and may even be gutted alive.
Another common method of commercial fishing uses ‘longlines’. These consist of thousands of baited hooks hanging from ‘lines’ of rope or nylon. These are then either anchored to the seafloor, catching fish like cod and halibut, or left to drift and catch swordfish, tuna, as well as many non-target animals.
Fishing inevitably catches non-target animals along the way (known as ‘bycatch’). These animals might be the wrong species, wrong size, wrong sex, or even be a protected or endangered species. This ‘collateral damage’ is merely dumped back into the sea, devastating the ecosystem.
Every night, enough ‘longline’ fishing nets are deployed into our oceans to wrap around the earth 500 times so it’s unsurprising that ‘bycatch’ is a serious issue. The FAO (Food and Agriculture Organization of the United Nations) estimates that around 10% of all aquatic species caught are thrown back – that’s at least 97 billion individuals being subjected to needless suffering every year.
Lost and discarded fishing materials are another risk factor. Around 300,000 whales and dolphins die every year from getting entangled in nets while 80% of the plastic in the Great Pacific Garbage Patch comes from fishing materials.
Overfishing is when more fish are caught than can be replaced through natural reproduction leading to ‘collapse’. The largest example of this was in 1992, when the Atlantic cod population decreased to less than 1% of its historic numbers due to fishing. One study suggests that, without drastic action, all fisheries will collapse by 2048 – there will simply be no more fish in the sea.
Farming fish
In response to declining fish populations, farming fish (a process known as ‘aquaculture’) has become the world’s fastest growing food production sector now accounting for nearly 50% of all fish consumed.
Ironically, the industry still relies heavily on wild-caught fish, who are ‘ground up’ into fishmeal to feed their farmed counterparts. Salmon, for example, are carnivorous and so 69% of fishmeal and 75% of fish oil goes towards supplementing their diets making the farming of fish inherently unsustainable.
Just like factory farms on land, the farming of fish is unnatural and unjust. While there are different systems of fish farming – some farms section off huge cages in the open ocean, while others transport fish to inland ‘ponds’ – they all result in immense suffering. It is infamously difficult to keep fish in conditions that are not stressful to them: if pens are too overcrowded then frustration can lead to aggression, fin damage, abrasions and stress, but if pens aren’t crowded enough then fish can feel threatened and vulnerable to predators. Different species of fish also prefer different types of water at different stages of their lives and benefit hugely from a complex, enriching environment (which cannot be provided on farms), so it’s impossible to ensure the welfare of all 77 million individuals who are farmed in the UK each year.
The conditions on fish farms are often dirty and crowded, and are a breeding ground for the spread of diseases and parasites like sea lice. Outbreaks can not only devastate whole populations of farmed fish but also affect the local environment either directly (when sick or non-native fish escape the farm) or indirectly through the water, which is highly contaminated with antibiotics, disinfectants, faeces, and additives.
Slaughtering fish: The largest animal welfare scandal of our time?
Fish have very little lawful protection at the time of slaughter. Individuals stolen from the wild are particularly vulnerable as they are caught and slaughtered at sea, away from the prying eyes of protocols and guidelines. At sea, fish begin suffocating as soon as they are lifted onto vessels. They will not be stunned so, unless they die a long, agonising death from suffocation (known as ‘asphyxiation’), they will be gutted whilst still alive.
Farmed fishes don’t fare much better. They too are typically asphyxiated and then bled to death, without stunning, but are also forced to endure periods of starvation (so that their digestive systems are empty during transport and slaughter), unsuitable storage and stressful transport practices.
Methods to slaughter fish are varied and none can be considered ‘humane’. For example, ‘percussive stunning’ (where the animal is hit in the head by a metal or wooden club) is considered humane as long as it causes instant death – but this cannot be guaranteed especially when trillions of fish are being killed every year. What fish are made to endure would be completely unacceptable for any other kind of animal.

Take action for fish
Killing an animal can never be considered humane because animals' lives are as important to them as ours are to us. Take action today for a kinder tomorrow.