Fish Farming Explained: concerns, alternatives, and impact

The sad truth about fish farms is that they add to, rather than reduce, the slaughter of wild fishes. Fish farming exposes wild populations to diseases and parasites they’re often not prepared to fight against, and can also have a significant impact on the environment.

Are they 'Fishes' or 'Fish'?

In his book ‘What a Fish Knows’, ethologist Jonathan Balcombe points out that referring to their plural as ‘fish’ lumps them together ‘like rows of insentient corn’. But the truth is that fishes are individuals with personalities, relationships, and the capacity to feel.

The Humane League UK wants to set an example of recognition and inclusion in the language that we use while fighting to improve the rights of fishes farmed for food. We advocate for using the plural ‘fishes’ instead of ‘fish’.

What is fish farming?

Fish farming is exactly what it sounds like: raising fishes on a farm. Of course, fish farms are different from other farms because they are made up of large tanks filled with water, or netted-off parts of the ocean.

Like other industrial farms, however, thousands of animals are packed together in a relatively small space, leading to severe outcomes for them and the environment.

When did fish farming begin?

People have been farming fishes since before 1000 BCE. Politicians during The Zhou dynasty were some of the first to describe raising carp. There is also evidence that Romans kept fishes they intended to eat in tanks.

Though fish farming has been around for thousands of years, the intense farming we know today didn’t gain a footing until after the Industrial Revolution. Today, fish factory farming has grown in prominence and become the standard by which fishes are raised for consumption.

Do fish farms pollute the ocean?

Fish farms contribute heavily to water pollution. As you might imagine, fishes, like other animals, produce waste. In the case of many fish farms, this waste is released immediately. The problem stems from the fact that a single fish farm containing 200,000 salmon produces the same amount of nitrogen as a city with 20,000 people, and the same raw sewage as 63,000 people.

As well as releasing huge amounts of nitrogen into the sea in the form of fish waste, fish farms are also a disease risk for wild fish. Farmed fish often have a heavy parasite load, and parasites like sea lice escape and infect wild fish living near fish farms.

With every open ocean fish farm there is also the inherent risk of escaping fishes. If fishes start to escape, they are likely to outcompete wild fish for food and other resources due to their large size. Adding to the issue is that often these farmed fishes are not native species; if enough escape, research suggests that they may be able to establish a new non-native population of fishes.

What types of fish farming are there?

There are many different types of fish farms. Though they may be different, none of them provide a safe way to raise fishes.

Cage systems

To make a cage or open ocean system, a section of ocean larger than an Olympic-sized swimming pool is sectioned off, and thousands of fishes are raised inside.

Though they have been hailed as a sustainable way to produce fishes, their open exchange with the rest of the ocean allows pollutants such as antibiotics, pests, and waste to escape.

Flow Through Systems

These farms are made up of a series of large tanks which are fed with fresh water by a near-by river. The water flows through the tanks, and back out into the river, taking with it waste material which may or may not be treated before entering the waterway.

Irrigation ditch or pond systems

There are many different ways to run an irrigation ditch and pond system. Some of them provide a relatively natural environment for fishes, as the enclosure grows algae and other marine plants for them to consume. Meanwhile, other farms following this system still feed their fishes an artificial diet. There is one commonality: the fishes’ waste is applied to nearby fields as fertiliser.

Integrated recycling systems

More widely known as aquaponics, integrated recycling systems use recycled water to raise both fishes and plants. The plants clean the water and use the nutrients in the fishes’ waste to grow.

What do farmed fishes eat?

It takes a lot of food to feed the millions of farmed fishes raised on industrial fish farms. And the irony? This need for food is mostly satisfied by killing wild fishes.

Salmon, for example, are carnivorous in the wild. So on farms, they are raised on diets that include fish meal and fish oil. These are produced from killing and processing fishes like herring, sardines, and anchovies. Around 440 wild-caught fish are killed to feed a single farmed salmon.

Can fishes feel pain?

People have been perpetuating the idea that fishes don’t feel pain for years, but a mounting body of research debunks this misconception.

Whereas a sibling or friend can tell you when they’re in pain, and a dog or cat will yelp when hurt, fishes endure silently. Instead, their pain is expressed through behaviours such as struggling when they are pulled out of the water and into a boat.

Even though they don’t express their pain vocally, analysis of their anatomy and behaviour has established that fishes do experience pain. Despite these findings, fishes lack even the few welfare protections afforded other farmed animals.

What's the difference between fish farming and aquaculture?

Though closely related, aquaculture and fish farming are actually not quite the same thing. Whereas all fish farming is aquaculture, not all aquaculture is fish farming.

This is because aquaculture encompasses raising any marine animal, and even marine plants, for food. Fish farming, on the other hand, refers solely to raising fishes.

How animals suffer in fish farms

For a long time, people believed that fishes were simple beings who couldn’t feel pain. We now know that fish farms are a source of significant animal suffering.

Environmental enrichment

Just like your dog or cat, fishes benefit from environmental enrichment. Whether that’s providing unique sensory experiences or interesting structures in their enclosures, fishes who are provided with enrichment have better welfare than those who are not.

Feeding

What do many farmed fishes eat? Other fishes. Raising millions of fishes on farms and feeding them other, smaller fishes is destroying ecosystems in (often less wealthy) parts of the world.

Stocking density

The RSPCA does not recognise stocking density – calculated as the weight of fishes per water volume – as a primary determinant of welfare.

However, being jammed so tightly together that you can barely move is clearly inhumane. Higher stocking densities are also a major factor in other welfare issues such as deteriorated water quality.

Water quality

Different species of fishes prefer different types of water at different stages of life. For example, increasing the water temperature when they’re young results in faster growth; however, much like chickens, if fishes grow too fast they are likely to suffer from deformities.

Slaughter

There are two ways fishes are slaughtered in the UK. In percussive slaughter, they are struck on the head before having their gills cut, causing them to bleed out. The alternative, electrical stuns, consist of irreversibly stunning them using an electrified water bath.

Investigations have revealed that both methods of slaughter can fail, leading the fishes to suffer immensely as they are killed.

Handling and transportation

In the rare event that fish farm conditions are perfectly calibrated to provide the best possible welfare for fishes, transport still presents as a welfare issue because of how quickly conditions can change, and the inherent stress that being handled causes fishes. Fishes often stop eating for days after being transported, providing evidence for just how stressful the move is for them.

Lack of space and crowded conditions

In order to maximise profit, fish farmers need to raise as many animals as possible, leading to overcrowding in their tanks and cages. When fishes are overcrowded, they are more likely to be aggressive toward each other. Further, an overcrowded fish farm provides the perfect conditions for the spread of parasites and disease.

Light disturbance

Because light affects how fishes behave, different types of light at different points in the day are often used to manipulate behaviour and biological systems.

Hunger

Some species of fishes, such as salmon and rainbow trout, are starved prior to slaughter to ensure their gut is empty.

Harm to the health of farmed sea animals

Fish farms are hotbeds for disease and injury for the fishes they house.

Does fish farming affect wild fishes?

The waste from fish farms, even those in enclosed systems, eventually makes its way out into other bodies of water. Even in the case of irrigation ditch systems, in which waste is applied as fertiliser to fields, it can seep into the groundwater.

What change is needed for farmed fishes?

Fishes deserve better than how we’re currently treating them. A good place to start is to grant them the same legal protections afforded other animals.

Are fishes protected by the law?

Though they are covered by some of the UK’s welfare regulations, fishes don’t have as many protections as some other animals, allowing for unimaginable animal suffering.

For many laws, fishes are actually not even considered an ‘animal,’ thus making them exempt from the protections that land animals have. But we’re working to change that.

Why is fish farming controversial?

The impact on ecosystems, wild fish populations, public health concerns, and animal welfare are just a few of the topics steeping fish farms in controversy.

Feeding

Many species of fishes are starved for part of their lives - a controversial, but standard, industry practice.

Stocking density

Not just an animal welfare concern, higher stocking densities lead to an increase in disease among fish.

Parasites and disease

Not only do farmed fishes suffer from diseases and parasites like sea lice, but they risk exposing wild populations as well.

Ecosystem impacts

Fish farms can expose wild fishes to diseases, parasites, and even competitors in the form of escaped fishes. All of these harm the ecosystem.

Genetic modification

Scientists are investigating how to make fishes more appealing to consumers, going so far as using genetic modification to remove their bones.

Labelling

Food labels are notorious for being misleading, and those on farmed fishes claiming to be sustainable or humane are often are no different.

Inhumane slaughter methods

Fishes often suffer immensely at slaughter, without any government inspections to ensure they are being handled appropriately.

Economic aspects of fish farming

As with other factory farms, a desire to increase revenue often leads to animal suffering. Fishes are packed too tightly together, or they are slaughtered while still fully conscious.

Alternatives to traditional fish farming

There are alternatives to the large-scale fish farming that has become the standard. One possible option are wild-caught fishes. However, if your goal is to be sustainable and ethical with your diet, then this option falls short on both counts.

Another possible alternative is aquaponics, a system that both grows plants and raises fishes using recycled water. However, ultimately, the fishes are still being farmed. Such systems have many of the same issues associated with traditional fish farms, just on a smaller scale.

Perhaps the best alternative is to simply swap fishes out for plant-based alternatives. In the near future, as cultivated options become more prominent, your options for suffering-free seafood is likely to grow.

How can you help fishes?

Contrary to what the industry would like you to believe, raising fishes for food does not solve the problems caused by wild fishing. Instead, it causes further welfare issues for the fishes living on these factory farms.

One of the best things you can do to challenge the industry is to stop eating fishes. To find some great plant-based alternatives, read our blog.

Want to make a difference for animals? Join thousands of others and start by signing the petition below, it'll only take a moment.