Why Do Vegans Avoid Fish?

November 20, 2025 •

4 min read

Over 2 trillion fishes are killed annually for human consumption worldwide. This staggering figure highlights the scale of an industry that vegans reject based on ethical concerns about animal sentience, severe environmental damage, and worrying health implications of eating fish.

Quick Summary

Vegans abstain from eating fish due to the recognized sentience of these animals, the extensive environmental harm caused by commercial fishing and aquaculture, and concerns over pollutants and contaminants.

Key Points

Sentience: Vegans avoid fish because scientific research confirms that fish are sentient beings capable of feeling pain and fear, making their exploitation unethical.
Environmental Damage: The industrial fishing industry causes significant ecological harm through overfishing, bycatch, habitat destruction, and vast amounts of plastic pollution from discarded gear.
Health Risks: Health concerns are a key reason why vegans avoid fish, which can be contaminated with harmful substances like mercury and microplastics.
Aquaculture Concerns: Fish farming, or aquaculture, involves animal cruelty in crowded, unsanitary conditions and pollutes marine ecosystems with waste and chemicals.
Clear Definition: At its core, veganism is defined as the practice of abstaining from all animal products, and since fish are animals, they are not included in a vegan diet.
Plant-Based Alternatives: Vegans can easily obtain essential nutrients often associated with fish, such as omega-3 fatty acids, from plant-based sources like algae oil, flaxseed, and walnuts.
No Misconceptions: Ethical veganism does not recognize a distinction between the flesh of land animals and aquatic animals; fish are not an exception to the principle of not harming animals.

Ethical Reasons: Fish Sentience and Welfare

One of the most foundational reasons why vegans avoid fish is rooted in animal ethics, specifically the growing scientific consensus that fish are sentient beings. Historically, fish were often viewed as unfeeling creatures, but modern research has debunked this misconception. Scientists have found evidence of pain and fear responses in fish that are comparable to those in mammals, noting that they possess pain receptors and exhibit complex behavioral reactions to painful situations.

The Cruelty of Commercial Fishing

Commercial fishing subjects billions of fish to immense suffering annually. The most common method of death for commercially caught fish is slow, agonizing suffocation after being pulled from the water. This is a painful and drawn-out process for creatures adapted to live and breathe underwater. Furthermore, fishing methods like trawling involve dragging immense nets through the ocean, capturing and killing countless non-target species in a practice known as bycatch. Animals like dolphins, sea turtles, and sharks are often caught and discarded as waste.

Environmental Impact of the Fishing Industry

The fishing industry poses one of the most significant threats to the world's oceans. Its practices lead to widespread ecological destruction and biodiversity loss.

Ecosystem Destruction

Overfishing: Industrial-scale fishing has depleted global fish populations to dangerously low levels. Some estimates predict that if current trends continue, there may be a collapse of wild fisheries by 2048.
Habitat Damage: Bottom trawling, a method where heavy nets are dragged along the seabed, destroys delicate marine habitats like coral reefs and mangrove forests, which are crucial for countless species.
Bycatch and Biodiversity Loss: The indiscriminate nature of fishing nets and longlines leads to the death of vast numbers of marine animals not intended for consumption, disrupting the delicate balance of ocean ecosystems.

Pollution from Fishing and Aquaculture

Ghost Gear: Millions of tons of plastic fishing gear, or 'ghost gear,' are discarded or lost in the ocean each year. This debris entangles and kills marine life, and contributes significantly to ocean plastic pollution.
Aquaculture Pollution: Fish farming (aquaculture) pollutes local waters with fish excrement, leftover feed, antibiotics, and pesticides, which can damage marine environments and spread disease to wild fish populations.

Health Risks of Eating Fish

Despite popular belief, fish is not without its health risks, a fact that contributes to why vegans avoid fish.

Contaminants in Fish

Mercury: Large, carnivorous fish accumulate high levels of methylmercury, a neurotoxin. Mercury exposure can cause neurological damage, memory loss, and is particularly harmful for pregnant women and developing fetuses.
Microplastics: With the increase in ocean pollution, microplastics are now found in seafood. Studies show that seafood eaters can ingest thousands of plastic particles annually, with potential links to cancer development.
Other Pollutants: Fish can also contain harmful chemicals like dioxins, which can cause other serious health problems.

Comparing Pescatarian vs. Vegan Approaches to Fish

While some people choose a pescatarian diet believing it to be a more humane or healthier option, vegans point to significant contrasts. The table below illustrates the differing perspectives.


Feature	Pescatarian View	Vegan View
Animal Sentience	Fish are often seen as less complex than land animals, justifying their consumption.	Scientific evidence confirms fish feel pain and fear, making their exploitation unethical.
Environmental Impact	Focus on sustainable fishing labels, viewing some fisheries as acceptable.	All commercial fishing, including 'sustainable' options, harms ocean ecosystems and contributes to pollution.
Nutritional Benefits	Believes fish is a necessary source of omega-3s, protein, and other nutrients.	Omega-3s and other nutrients can be obtained from plant-based sources like algae oil, flax, and chia seeds.
Pollution Concerns	Might dismiss health risks or choose species with lower levels of contaminants.	Acknowledges the widespread contamination of fish with mercury and microplastics, avoiding all risk.

Reframing Our Perspective on Fish

Ultimately, the question of why vegans avoid fish comes down to recognizing fish as individual, sentient beings rather than commodities. The vegan philosophy seeks to exclude all forms of animal exploitation, and the fishing industry, whether wild-caught or farmed, is undeniably a system of exploitation and harm. By choosing plant-based alternatives, vegans promote a more compassionate and sustainable food system that protects not only animals, but also the health of the oceans and the planet as a whole.

To learn more about the complexities of the fishing industry, the documentary Seaspiracy offers an eye-opening perspective on the vast environmental and ethical issues.

Conclusion

The decision for vegans to avoid fish is based on a well-rounded set of principles. It involves the ethical recognition of fish sentience, a commitment to protecting the environment from industrial fishing and aquaculture, and a desire to avoid the health risks posed by contaminated seafood. The vegan stance is not an arbitrary rule but a comprehensive approach to living that seeks to reduce harm and injustice across the board.

Frequently Asked Questions

No, a person who eats fish cannot be considered vegan. Since fish are animals, consuming them violates the core principle of veganism, which seeks to exclude all animal products and exploitation. A diet that includes fish but no other meat is known as pescetarian.

Yes, extensive scientific evidence shows that fish are sentient and have the capacity to feel pain and fear. They possess pain receptors and exhibit complex physiological and behavioral responses to pain, contrary to outdated beliefs.

No, the commercial fishing industry is far from environmentally friendly. Practices like overfishing, bottom trawling, and bycatch cause extensive damage to marine ecosystems, leading to habitat destruction and declining fish populations.

Fish farming, or aquaculture, is not a sustainable or ethical alternative. It contributes to water pollution from concentrated waste and antibiotics, and confines fish to cruel, crowded conditions that often lead to disease.

Vegans obtain omega-3s from a variety of plant-based sources. This includes nuts and seeds like flax, chia, and walnuts, as well as algae oil, which is where fish get their omega-3s in the first place.

Bycatch is the incidental capture and killing of non-target marine life, such as dolphins, whales, and sea turtles, during commercial fishing operations. Vegans oppose this practice due to the unnecessary death and exploitation of animals.

Yes, fish can contain contaminants that are harmful to human health. Risks include exposure to mercury, which can cause neurological damage, and microplastics, which have been linked to cancer development.