Fish Farming: Harming Oceans While Poisoning People and the Environment

pollution from fish farming

If you ask a random meat-eating person if they think fish is meat, there is a good chance they will say no.

In fact, many vegans and vegetarians are offered fish options when they tell a server they don’t eat meat.

But why is that?

Why do so many people around the world not think of fish as meat?

Religion, that’s why.

In Summa Theologica, St. Thomas Aquinas talks about fasting as an act of virtue as in order to bridle the concupiscences of the flesh, which regard pleasures of touch in connection with food and sex. Wherefore the Church forbade those who fast to partake of those foods which both afford most pleasure to the palate, and besides are a very great incentive to lust. Such are the flesh of animals that take their rest on the earth, and of those that breathe the air and their products, such as milk from those that walk on the earth, and eggs from birds. For, since such like animals are more like man in body, they afford greater pleasure as food, and greater nourishment to the human body, so that from their consumption there results a greater surplus available for seminal matter, which when abundant becomes a great incentive to lust.

The interpretation is clear and the tradition of not classifying fish as a kind of meat was born. The reason? They are not land animals and don’t breathe air.

It doesn’t matter that most people aren’t aware of this history lesson.

Friday fish fries and other traditions passed down from generation to generation have accidentally classified a living and breathing sentient being as an “other” animal. “Not real meat.”

Inventing a Category to Make Fish Seem as if it Wasn’t an Animal

By doing so, we even have a category of diet like pescatarians. Pescatarians make the exception of eating fish (and usually shellfish), but not other animal meats.

It doesn’t even seem odd to read “pescatarian” because it is so common. Imagine, however, if there was a “cowatarian” or “pigatarian.”

It would seem hypocritical of someone to only eat pigs or only eat cows but no other living animals. It wouldn’t make sense.

But in the 750 years since Aquinas inadvertently influenced people to not consider fish as worthy animals to avoid during a fast, humanity has essentially disregarded their sentience in the process.

So why does that matter?

Fish Consumption is on the Rise

The data in the graph below is simply staggering:

fish consumption growth

This shows the data, in metric tonnes, the amount of fish produced on a global scale. In 2013, the number of farmed fish exploded past capture fisheries and only continues to climb up and to the right.

Since 2013, 44% of American and British consumers that were asked in a Cargill survey said they have started eating more fish.

According to Cargill, it’s because people are more concerned with their health and sustainability issues when it comes to the environment.

But how sustainable is fish farming?

Before getting into that, let’s first look at fish farming in general.

What is Fish Farming?

Fish farming is the industrial practice of aquaculture where huge quantities of fish are bred and raised in enclosed, unnatural conditions and to be slaughtered in a commercial setting and sold as food. Approximately half of all fish eaten around the world come from industrial fish farms.

Farmed fish are typically grown in large tanks, industrial enclosures, sea cages, net pens, or small ponds to produce high yields of fish in short periods of time.

A study produced by the World Bank, Food and Agriculture Organization of the United Nations (FAO), and the International Food Policy Research Institute (IFPRI) predicted that by the year 2030, two-thirds of the global food fish supply will come from fish farming.

While many people within the fish industry say that fish farming is done for sustainability reasons and to not overstress the marine environment of the oceans, there is a lot more to it than meets the eye.

It can take up to five pounds of smaller wild fish from the ocean that are fed to the farmed fish to produce just one pound of fish meat from salmon or bass, two of the most common fish being raised on factory farms. The methods used to capture these wild fish that become farmed fish food are appalling. Trawling is a dangerous form of industrial fishing that literally scoops up anything in the net’s path.

Farmed Fish Are Not Healthy, Contrary to Popular Belief

farmed fish are not healthy

The similarities between the “quality” of the animal raised in confined captivity to those raised naturally are eerily similar to factory farmed livestock like cows, pigs, and chickens.

At the end of the day, the companies responsible for raising these animals care about their profit. When the bottom line is involved, many things are done to make business more efficient and more profitable.

The shortcuts that are taken and the practices implemented can cause a lot of harm in the long-term to have quick gains in the short-term.

Farmed Fish Health Risks

There are many reasons that the farmed version of fish is less healthy than wild fish. While farmers may argue the following practices are for the wellbeing of the fish, the reality is they don’t want to hurt their profit margins.


Like animals raised on factory farms, farmed fish are fed high quantities of antibiotics. While it can be argued this is done with good intentions, the reality is more sinister.

The conditions where fish are raised on factory farms are so crowded that if a fish gets sick it is possible to spread the disease to countless other fish.

While it’s nice to think that farmers don’t want fish to get sick, the problem with consuming too many antibiotics is obvious. The fish can become resistant to the antibiotics and can make it more difficult for them to fight off disease.

What’s even scarier is the potential for humans to develop resistance to antibiotics as well. When humans continuously consume that are present in the food they eat, they can develop a resistance that potentially harms them down the road if they need to take a certain antibiotic to fight off illness.

Dr. Danilo Lo Fo Wong, Programme Manager for the Control of Antimicrobial Resistance at the WHO says the “Overuse of antibiotics—in farming or for human medical treatment—speeds up the development of antibiotic resistance, which is when bacteria change and become resistant to the antibiotics used to treat infections they cause. This is compromising our ability to treat infectious diseases and undermining many advances in medicine.”


According to the Environmental Working Group, “seven of ten farmed salmon purchased at grocery stores in Washington DC, San Francisco, and Portland, Oregon were contaminated with polychlorinated biphenyls (PCBs) at levels that raise health concerns.”

PCBs cause cancer in animals are probably human carcinogens, and their production was banned by the United States government in 1978 after discovering just how toxic this chemical actually is.

Many studies show that PCB is highly prevalent in the fishmeal that is fed to farmed fish. The twisted irony? Many of the fish that compose the fishmeal is also grown on fish farms around the world.

Toxic Chemicals in Farmed Fish

Other alarming chemicals that are typically found in farmed fish include dibutyltin, Polybrominated Diphenyl Ether (PBDE), and dioxins

Dibutyltin, which is commonly used in the production of PVC plastic, can increase the risk of prediabetes and obesity if consumed by humans.

PBDE consumption by humans can alter thyroid hormone homeostasis and cause thyroid dysfunction. This can lead to the subsequent development of thyroid cancer.

According to the World Health Organization, the consumption of dioxins can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer.

How Fish Farming Affects The Environment

There are a number of ways that fish farming negatively impacts its local environment. Environmentalists and activists are fighting to ensure that fish farming operations take a more eco-friendly approach of doing business.

Animal rights group PETA says that “you can’t be an environmentalist and eat fish flesh – period. Just like commercial fishing, aquafarming desecrates natural waters.”

Beyond polluting natural waterways and harming local marine life, fish farming negatively impacts the local environment in many other ways.

Fish Farming Compromises the Soil

Not all businesses last forever. There can be a wide variety of reasons a business closes shop. The same is true in the fish farming industry.

When a fish farm closes, regardless of the reason, they leave behind an ecological mess that can take a very long time to recover.

The soil surrounding a fish farm operation will take a major hit. The soil will remain hypersaline, acidic, and eroded. Because of these issues, the soil will become essentially useless for future agriculture projects.

The Pollution of Waterways and the Water Supply

As discussed early, fish farming uses a lot of chemicals in the production process. The combination of fertilizers, chemicals added fishmeal and water, antibiotics, and pesticides can make the water runoff from fish farms toxic.

This water will find its way into local waterways and eventually back into the ocean. Beyond polluting the local marine ecosystems, this runoff can find its way into the local water supply meant for human consumption.

One study showed that “preliminary calculations revealed that an intensive aquaculture system farming three tons of freshwater fish can be compared, in respect to waste generation, to a community of around 240 inhabitants.”

Overfeeding the fish populations on fish farms causes a major problem as well. Because the feed is packed with chemicals, this can lead to the eutrophication and nitrification of local ecosystems.

The Spread of Sea Lice (and Other Diseases)

What happens on fish farms could have long-lasting and detrimental impacts on wild populations of marine life.

Farmed salmon, for example, are commonly infected with a form of sea lice called Lepeophtheirus salmonis.

These lice find their way beyond the confinement of the fish farms and into natural marine habitats. This causes infection upon wild populations and the imminent death and potential extinction of wild, native species of salmon.

In fact, some reports show that “salmon farms can cause parasite outbreaks that erode the capacity of a coastal ecosystem to support wild salmon populations.”

The Biological Contamination of Introducing Exotic Species

Introducing a new species into a foreign ecosystem can cause catastrophic changes. This has been well documented for hundreds of years across countless occurrences.

One of the most infamous stories was the toad infestation of Australia in the 1930s. When a beetle was discovered to be destroying sugar cane crops, they imported 102 cane toads from Puerto Rico to help clean up the beetle problem. Those 102 toads eventually turned into more than 1.5 billion.

Evasive species like this can run amuck on new ecosystems and the species that call them home.

Some of the most pressing issues when it comes to introducing foreign species into a new environment are the displacement of native species, competition for space and food, and pathogens spread.

Fish Farming is Cruel to the Fish

fish suffering

Like all animals raised on factory farms, the treatment and conditions of fish are far from decent.

In fact, because of few regulations, the treatment of fish is even worse.

Like on factory farms of land animals, fish farmers cram as many fish as possible to ensure profit maximization. Beyond the potential of spreading diseases and parasites in cramped living spaces, the chances of injury increases as well.

According to research by Royal Society Open Science, the living conditions on factory fish farms can lead to high levels of stress and depression in the fish.

Marco Vindas, the lead author of the study, says that “fish are capable of complex behavior and their brain system has a lot of similarities with that of mammals, including humans.”

Beyond the horrific conditions that the countless fish are forced to spend their short lives, the different ways they are killed can inflict unnecessary pain and suffering to the fish in their final moments.

According to an investigative report by Compassion in World Farming, it was found that numerous fish “suffer slow, painful deaths by asphyxiation, crushing, or even being gutted alive.”

Even more shocking, the report found that “sea bass and sea bream are commonly dumped into large buckets of ice slurry, where they thrash about, fighting for their lives, as ice gets lodged in their gills and they struggle to breathe. They can remain conscious throughout this ordeal, and many are still alive when they are packaged up in Styrofoam boxes, ready to be sold.”

Farmed Fish Versus Wild Fish: Which is Better?

is farmed fish better than wild fish

This question can be debated from both sides with pros and cons. But at the end of the day, the conclusion is clear: both are extremely bad for marine life.

So it shouldn’t be a question of whether one is better than the other but an argument for why you should avoid both altogether.

Current industrial fishing practices are trawling the ocean dry and killing countless lives to provide humans with something that is unnecessary to our survival.

Industrial fish farming practices are not just killing billions of fish every single year, but also poisoning people and local ecosystems.

And while both practices have their cons when it comes to human health and environment impact, one fact is clear: Consuming fish is a personal choice for people consuming a Western Diet, not a staple for survival.


Avoiding both farmed fish and wild fish is the solution.

Becoming a vegan is the best way to show the food industry you don’t support the cruelty, suffering, and slaughter of sentient beings.

And while habits might be hard to break, there are countless of vegan and vegetarian recipes out there that can help you fill your hankering for fish.

A lot of people will say they just can’t give up sushi and that’s why they don’t change from being a pescatarian to vegetarianism or veganism.

But if you search ‘vegan sushi’ into Google you will find endless results. It is exploding in popularity and Japanese restaurants around the world are adding vegan options to their menus.

In the meantime, as we continue pushing toward a food industry with less cruelty, the best thing you can do is avoid fish altogether.