The Pescatarian Dilemma—Experts Weigh In On Whether Fish Really Feel Pain

Despite social acceptance of the pescatarian diet—which includes vegetables, grains and sea food—new evidence suggests that eating fish could be one of the most unethical and unsustainable things humans can do.

Aquaculture is the largest form of intensive farming in the world, with roughly 160 billion fishes killed globally every year, compared to 60 billion chickens, but with far fewer regulations protecting fish from suffering in life and slaughter.

Recent research strongly suggests that fishes feel pain in a similar way to humans, even self-medicating to reduce their suffering. If fishes do feel pain, there are huge ethical implications and issues with the current welfare standards of the commercial fishing industry, including wild and farmed fishes, and their unregulated slaughter practices.

After the release of the Pixar film Finding Nemo in 2003, whose plot centered around a clown fish captured from the wild to be sold in the tropical fish market, sales of clown fish went through the roof. Dubbed the "Nemo effect", the irony that a film about conservation resulted in a depletion of clown fish in the wild was not lost on conservationists.

How do fish feel pain, and why do humans turn a blind eye?

'I Eat Fish To Add More Variety To A Vegetarian Diet—I Don't Think They Feel The Same Type Of Pain As A Mammal'

Sue, 60, from Michigan, who asked to use a pseudonym for fear of backlash from both animal welfare and meat-eating supporters, has been a pescatarian since the early 2000s, and the majority of her family are vegetarian, even her fisherman son.

Despite a passion for animal welfare—she even makes sure she "clean kills" any bugs she comes across—Sue predominantly eats fish because she likes the taste, her husband eats fish, and because she believes it adds more variety to a vegetarian diet.

When asked if she believed fishes felt pain in a significant way, she responded, "I have looked into it and I think like with a lot of things I don't think anyone really knows. I personally think they feel something, but I don't think it's the same type of pain as a mammal."

She cited the idea that, unlike mammals, fishes don't care for their young, as her main reason for putting them in another category to chickens or cows.

"A salmon that swims upstream to die, and lays thousands and thousands of eggs is not the same as a warm-blooded mammal that feels pain and emotion," she said. Another reason Sue eats fish is for diet diversity, especially when it comes to fast food. "I can hear the stupidity and hypocrisy coming out of [my] mouth," she said, "but I do like to eat fast food, and the vegetarian options aren't great, so I go for the fish options."

Do Fish Feel Pain?

For years it has been generally accepted by large sections of society that fishes feel pain and emotions very differently to other animals, if at all. Feeling pain not only requires a physical response but an emotional one, and it has long been argued that fish do not have sufficient capacity to understand fear, or the density of appropriate nerve fibers to experience pain in a significant way.

One 2015 study, entitled "Fish do not feel pain and its implication for understanding phenomenal consciousness," argued that fish lack a cerebral cortex and therefore "cannot experience pain or fear". The cerebral cortex is the part of the brain considered to be the "thinking" area, and if this theory is to believed, then only humans and primates have the ability to feel "emotional pain," as they are the only creatures with a cerebral cortex.

The ability to feel pain is an acute survival necessity for all sentient beings, enabling us to respond to indications of danger and protect ourselves. If animals didn't feel pain or fear, then it's likely they would harm themselves constantly, and many species we see today would have become extinct through their own behavior, and fish are no different.

The most convincing evidence that fishes feel pain, even without a cerebral cortex, was discovered in 2002 by Sneddon, along with her colleagues Victoria Braithwaite and Michael Gentle. They were the first to discover that fishes had nociceptors, pain receptors that give them the ability to feel physical pain, and the potential to feel emotional pain.

"These nociceptors in fishes respond to stimuli like cutting, crushing, and chemicals, and we discovered they have them throughout their body in the face, lips, eyes and fins", said Sneddon, "and we found that pain responses were incredibly important in fishes, making them behave differently in various situations".

One of the first groundbreaking experiments undertaken by Sneddon and her team found that fishes respond to pain in a similar way to human beings. Anesthetized rainbow trout were injected with acetic acid, vinegar, just under the frontal lips, resulting in anomalous behaviors. The fish immediately stopped feeding, and began rubbing their lips along the side of the tank. "It was a bit like when we stub our toe," said Sneddon, "we instantly grab it and start rubbing it." The researchers observed that the pain response in the fish lasted roughly three hours, the same response to the same stimuli in humans, and it was only after this time that normal movement and feeding resumed.

Another test administered on zebra fish found that they not only feel pain, but possess the self-awareness to choose to self-medicate, and will pay a price to relieve their pain. Zebra fish are social creatures that are averse to bright light, and the fish were kept in a baron tank for seven months with no stimuli, then put in what Sneddon referred to as a "choice chamber." They then had the choice whether to enter a tank with unfavorable bright lights, or a more inviting unlit tank with gravel, a fake plant and the appearance of other zebra fish. They chose the enriched tank six times in a row.

"We then injected them with a painful stimuli, and dissolved painkillers in to the brightly lit, unfavorable tank," explained Sneddon, "We saw the loss of preference for the favorable tank for the one with the painkiller in it, proving that the fish not only felt the pain, but were willing to do something unpleasant and bear the bright lights to reduce the pain."

The Ethical Implications Of Eating Fish

If we are to believe that fishes have a capacity to feel pain like terrestrial animals, or even humans, then it is necessary to review the welfare implications of the commercial fishing industry, and the conditions in which fishes are kept, caught and slaughtered.

"As with other forms of intensive farming, you're denying the needs of the animals in order to increase yield and therefore profit," animal rights activist and philosopher Peter Singer told Newsweek. Singer is the author of multiple books on the subject, including Animal Liberation: A New Ethics for Our Treatment of Animals, originally published in 1975 and republished in May.

1. Farmed Fishes

The most commonly farmed fishes in the U.S. include salmon, bass, trout and tilapia and these fishes spend their entire lives in cramped, overcrowded tanks and are prone to necrotic diseases, and aggression from larger fish.

Salmon are solitary fish in the wild, and can travel over 1,000 miles in their lifetimes to spawn and feed, a primal instinct denied them in an overcrowded tank. "There is a lot of evidence available that farmed fish are stressed, and they display repetitive behavior in these tanks, swimming around in small circles, not unlike caged lions and tigers in concrete enclosures in old fashioned zoos," said Singer.

Farmed fishes are very susceptible to disease in these conditions, almost always suffering from sea lice, which are harmless to humans but eat away at the flesh and feed off the blood of the animals. Farmed fishes have also been seen to suffer from sunburn, if their enclosures are not protected, and when they are ready to be harvested, they are sucked from the tank up a long tube, which they fight against, meaning they are almost always exhausted and stressed by the time they reach the end.

"It wouldn't be acceptable to walk past a field and see a cow covered in lice," said Sneddon, "they're part of our aesthetic landscape, but because fishes are hidden we seem to be able to overlook this fact."

2. Wild Caught Fishes

While wild-caught fishes get to live in their natural habitat, issues arise with their capture and slaughter. There are multiple ways to mass catch wild fishes including long lines, where hundreds or thousands of fishes at a time will be speared alive on hooks to act as bait for larger target fishes. The target fishes then swallow the hook and can be there for hours while the fishermen catch their quota. Trawler nets will catch hundreds of animals at a time, and drag them quickly to the surface, causing their swim bladders to burst, for the same reasons a scuba diver must ascend to the surface slowly to avoid "the bends".

3. Slaughter

One of the most controversial issues with commercial fishes is the way in which they are slaughtered. Wild fishes are often dumped on the surface of the boats, and die under the weight of other animals, from blunt trauma, or suffocate, according to Singer. "With farmed fish, the gills are often cut out while the fish is still alive, leaving the animal to suffocate in pain, or bleed to death, for up to 40 minutes in some cases," he said.

"Other techniques have included carbon dioxide narcosis for salmon and trout, whereby CO2 is pumped in to the water, which causes brain damage, and fishes have been observed swimming vigorously trying to escape the tank. The CO2 takes effect within two to four minutes, but they reman conscious and able to feel until killed."

Electrocution is thought to be the most ethical way of killing fishes before removing them from the water. However there is no requirement for any slaughter regulation with fishes in any country, unlike the strict laws for terrestrial animals. No welfare standards exist for the trillions of fish harvested from the wild each year at time of writing.

Organizations do exist that seek to promote sustainable and ethical fishing techniques, however they tend to focus mainly on sustainability and the health of the oceans, rather than the welfare of individual fish once caught. The Marine Stewardship Council, a non-profit organization, for example, aims to use an ecolabel and fishery certification program to recognize sustainable fishing practices.

How Can We Eat Fish More Ethically?

It would appear that all fishes, unless you catch and swiftly dispatch them yourself, will likely have suffered on the way to your plate, whether in life or death. Until legislation to protect fishes is as comprehensive as with terrestrial food animals, it remains a controversial food source.

"There is no ethical way to eat fishes at this time," argued Singer, who also highlighted the suffering of live fishes in restaurants, including a recipe for a popular south Asian soup featuring loaches, who have salt poured on them alive to purge them. In many foodie videos on YouTube, the fish can be seen writhing in perceived pain before being boiled alive.

Thinking about your carbon footprint can help ensure you eat more sustainable fishes, according to Sneddon. "Try and eat local fishes," she said, "and think about the species you are eating. Some fisheries have certification schemes that label them as sustainable or more environmentally friendly, so look for them, and you can do research to find out whether the fishery uses stunning to kill the animals."

Singer suggested eating more carp, a mainly herbivorous fish that can thrive better in farm environments, but said that until fishes can be affordably grown at a cellular level, there will still be pain and suffering.

Sneddon and Singer agree that despite popular opinion, it is actually less ethical to eat fishes than other proteins due to their equal ability to feel pain, and the disproportionate suffering they experience in an unequally regulated industry.

So we know that fishes feel pain, and you don't have to look hard to discover the dark side of the fishing industry. It simply comes down to whether you care about animal welfare, and yes, that does include fishes.

Do you have a dilemma that needs solving? Let us know via life@newsweek.com. We can ask experts for advice, and your story could be featured on Newsweek.