When I decided to stop eating animals for ethical reasons five years ago, I wanted to make sure I could stick with it. Following a path where, I thought, each step brought me closer to the most moral diet, I became a pescetarian first, swapping chicken quesadillas and beef burgers for salmon poke bowls. This went on for a year before I adopted a fully vegetarian diet.

Pescetarianism — the practice of eschewing red meat and poultry but still eating seafood — is often recommended to people who want to make better food choices, but don’t want to go vegan or vegetarian. Fishing typically has a smaller carbon footprint than factory farming, fish are often seen as less worthy of compassion than land animals, and, while wild-caught fish lives are cut short, at least they don’t spend their entire existence in cages so small they can’t turn around, like some factory-farmed animals. Many people ease into thinking and acting more critically about what (or who) they’re eating this way, which is something we should laud in a society that eats billions of animals raised in terrible conditions without giving it much thought.

Nearly a quarter of Americans report that they’re trying to eat less meat, motivated more by concern for the environment than for animal welfare. This matches my experience: saying that you’ve stopped eating animals because of concern for the animals themselves tends to provoke more hurt feelings and tense conversations than citing health or environmental reasons. And switching from an omnivorous diet to a pescetarian one is likely to reduce your climate impact because on average, seafood production releases less carbon per pound of meat than raising land animals (though there is huge variance depending on the species).

But even though I shrank my carbon footprint by going pescetarian, I now think I was actually doing more harm to animals during my year of fish than when I was just a regular omnivore.

For one thing, scientists have amassed evidence over the past 20 years that fish are sentient — that they feel pain, experience emotions, and engage in complex social behavior that we once thought was limited to humans and land animals — upending decades of received wisdom that they don’t matter morally because they can’t really suffer.

Then there’s the question of numbers. Even if you’re less confident that fish can suffer like as pigs or cows, or you just have less empathy for them, keep in mind that you typically have to eat many more individual fish to get an equivalent serving of food. An average farmed salmon yields just under four-and-a-half pounds of meat. That’s over 30 times less meat than a single pig and over 100 times less than a cow. Salmon and chickens produce a similar amount of meat per animal, and both experience intense suffering on industrial farms, but farmed salmon live roughly 26 times longer than chickens before reaching slaughter weight, which means 26-fold more time spent in pain. And unlike farmed land animals, lots of the fish we eat are carnivorous, so they eat a huge number of bait fish before they make it to your plate, which only adds to the pescetarian’s moral bill.

When I went pescetarian, I started eating around two pounds of salmon a week, the equivalent of one to two entire Atlantic salmon every month. The typical farmed salmon is fed 147 fish over the course of their short lives — which meant that I was responsible for somewhere between 1,700 and 3,500 fish deaths per year from eating salmon alone. By comparison, the typical American eats around 25 land animals in total per year (based on data from a decade ago, but current figures are similar).

So it’s little surprise that, according to one estimate, humans catch or farm at least 840 billion to 2.5 trillion fish each year — at least 11 times the combined number of cows, chickens, and pigs slaughtered globally, even though seafood makes up just 17 percent of the world’s animal protein intake.

These numbers are expected to increase — even more so if more consumers change how they’re eating to primarily help the climate, without worrying too much about animals. There’s a well-known trade-off here: a diet of small animals like chicken or anchovies instead of large ones like cows has a smaller carbon footprint but results in suffering and death for a far greater number of individual animals.

Fortunately, there’s a simple way out of this dilemma, one that is better for both animals and the climate: instead of swapping one animal for another, eat fewer animals of any species and more plants.

Our weird relationship with fish

While I’ve never had any interest in hunting, I grew up fishing with my grandfather in the Florida Keys. When I was a boy, I remember watching with concern as he beat a fish to death with the handle of a knife. “Fish don’t feel pain,” he assured me. The fish’s writhing around on the prep table suggested otherwise, but hey, I thought, he knows a lot more about fish than I do.

It’s hard to imagine this being seen as normal in the context of, say, hunting a deer, and hunting itself is a more culturally contentious activity than fishing. Americans are more disapproving of hunting than fishing, according to a 2019 survey conducted by hunting and fishing advocates.

The same goes for how we raise the animals we eat. While we routinely treat land animals on factory farms in unconscionable ways, we tolerate even worse treatment of fish. Wild-caught and farmed fish are routinely left to suffocate in open air or killed by a combination of suffocation and being cut open alive. Fish aren’t covered by the US Humane Methods of Slaughter Act, so they get essentially no protection from cruelty. It’s much less likely consumers would tolerate the routine slaughter of chickens via drowning, which the US government at least nominally prohibits (although this still happens in poultry slaughterhouses).

To take one extreme example: there’s a Japanese culinary tradition called ikizukuri — roughly translated to “prepared alive” — where sashimi is prepared from the body of a still-living fish right in front of the customer. Can you imagine a Manhattan restaurant carving off the flank of a squealing pig right in the middle of the dining room?

Of the animals we eat, fish and other seafood — a term that, really, says it all about how we view aquatic life — get the least moral consideration. Why? As Vox’s Kenny Torrella writes: “They live underwater, so we rarely interact with them. They can’t vocalize or make facial expressions, so it’s much harder to understand them than mammals and birds. And research has shown that the further animals are from us on the evolutionary chain, the less likely we are to try to protect them.”

The shifting consensus on fish pain

Our evolutionary distance from fish has contributed to the now-debunked myth that, as my grandfather believed, they don’t experience pain. The most common biological argument against fish pain went something like: humans experience pain in the brain’s neocortex, but fish don’t have a neocortex. Therefore, fish can’t experience pain.

Becca Franks, a professor of environmental studies at NYU, counters this argument with the example of the octopus. Humans need their visual cortex to see, but octopuses don’t have a visual cortex. That doesn’t mean they can’t see — it just tells us that they process vision differently. Vastly disparate animal species have independently developed vision with different eye and brain structures, in a phenomenon known as convergent evolution. The same thing has been found in birds, who were once thought to lack intelligence but are now acknowledged by neuroscientists to have developed capacities that are strikingly similar to humans. (Scientists are still learning about the extraordinary abilities of crows, for example, who can create tools to retrieve food). We should expect functions that provide animals with an edge in survival, like vision and logic, to arise in different species independently.

Similarly, there’s an evolutionary incentive for animals to develop the ability to detect and avoid pain. Donald Broom, a professor of animal welfare at Cambridge University, has argued that pain and fear systems in animals evolved a long time ago and are unlikely to have suddenly appeared in just mammals or humans.

In 2002, around the time my grandfather first taught me to fish, zoologist Lynne Sneddon discovered nociceptors — neurons that react to potentially painful stimuli — in fish. While we can’t exactly ask fish if they feel pain, Sneddon and other researchers have devised clever ways of getting to an answer. To distinguish reflexive behavior from behavior that can best be explained by a subjective experience of pain, a common approach is to look at how painful stimuli affect fish behavior, like by making them avoid predators or novel objects, with and without the presence of painkillers like morphine or aspirin.

To take one example, when zebrafish are presented with the choice between a tank enriched with things like pebbles and fake plants or a barren tank, they’ll consistently choose the former. Their preference persists when they’re injected with noxious acetic acid (vinegar). But when the barren chamber is filled with a painkiller and the enriched chamber isn’t, the zebrafish will prefer the barren chamber.

Fish form surprisingly complex social bonds

Some researchers, like Franks, think the fish pain debate is missing the point. Rather than getting bogged down with contrived experiments, they argue, we should look more closely at fish behavior in their native environments, where they show clear evidence of sentience and express preferences. As Franks told me the relevant question is, “Are those preferences more than just reflexes, and instead felt experiences, felt emotions, and strong desires about the conditions of their life?” She firmly believes that all conscious creatures have evolved to enjoy the process of survival and that prey species may even get a thrill from evading predators.

While Sneddon has focused a lot of her efforts on determining if fish can feel pain, when I spoke to her, she, too, was quick to point to broader evidence of fish sentience, which she defined as an animal’s ability to form relationships both within and across species. She cited the example of moray eels teaming up with grouper fish to form a hunting relationship, one in which the eels use their flexible, slender bodies to flush prey out of hiding places for the speedier grouper to catch. When teamed up, each predator gets to keep the kill about half the time.

One thing that first convinced me to stop eating sea creatures was a 2018 talk on the inner lives of fish by Franks. She pointed out that even tiny fish exhibit surprisingly complex social behavior. Take the cleaner wrasse fish, which eats parasites off of larger fish. Occasionally, they’ll eat a scale off that big fish by mistake, and to “apologize” to them, they’ll give a literal back rub, providing extra attention to predatory fish. All this in a fish less than six inches long!

Reinhard Dirscherl/ullstein bild via Getty Images

Cleaner wrasse fish who see their reflection will attempt to remove marks on their scales, joining a small handful of species in passing a self-recognition test. These fish also outperform three primate species, including orangutans, in a foraging task requiring advanced social intelligence, which may help explain their delicate masseuse sensibilities.

The list goes on: guppies have friends, salmon probably jump for fun, monogamous convict cichlid fish exhibit more pessimistic behavior after a breakup, and Japanese puffer fish make flirtatious art.

These capacities should have profound implications for all the ways we interact with fish, from sport-fishing to scientific research, but by far most of our interactions with fish are with the ones we eat. And the suffering we cause in those interactions is incalculable.

The terrible lives of the fish we eat

Consumers get mixed messages about whether farmed or wild-caught fish are better for the environment. The reality is complicated — it depends a lot on the species, harvest method, and location — giving rise to byzantine resources designed to help consumers make sustainable seafood choices. But it’s tough to even confirm where the fish on your plate came from: a 2015 analysis of salmon in a variety of US restaurants and groceries found that 43 percent was mislabeled — typically falsely claiming it was wild-caught when it was in fact farmed.

Given the overwhelming evidence for fish sentience, the ethically motivated eater can rely on neither. And the distinction between farmed and wild-caught begins to break down when you consider the close relationship between commercial fishing and aquaculture, also known as fish factory farming. Over 90 percent of all fish humans slaughter are wild-caught, but about half of those are eaten not by humans but processed into fishmeal (mostly eaten by farmed fish and crustaceans) to accommodate the rapidly growing fish farming industry. A recent study estimated that the number of fish farmed globally grew ninefold in the last three decades, up to 124 billion in 2019.

Raising fish in confined conditions far different from their natural environments presents severe ethical problems, to say the least. Farmed fish suffer from overcrowding, disease, and the pain of being forced to grow rapidly. They experience significantly higher mortality rates than those of farmed land animals, while diseases that spread in dense fish farms also threaten wild marine populations.

Eating wild-caught fish — assuming you can actually be sure that’s what you’re getting — may be less bad from an animal welfare perspective than eating farmed ones. As brutal as standard capture and slaughter methods for wild fish are, they inflict a few hours of suffering instead of the months or years it takes to raise animals on farms.

But commercial fishing creates plenty more externalities that go beyond the fish consumers directly eat. Ecosystem destruction is practically baked into its business model. Common fishing techniques like bottom trawling — dragging a large net across the sea floor — can cause severe damage and pollution. Fishing boats inadvertently catch many marine animals — like dolphins, whales, and turtles — known as bycatch, a category that includes about 10 percent of wild-caught fish, according to Our World in Data. Animals caught as bycatch are then tossed back, but most don’t survive.

Selene Magnolia/We Animals Media

I’d be remiss not to mention shrimp, which are by far the most numerous individual animal species Americans eat, at over 120 per person per year on average. We have less evidence of shrimp sentience, but this is mostly due to our lack of research on it. Shrimp do respond differently to noxious stimuli when given painkillers, providing some evidence for their ability to experience pain. And shrimp farming involves some of the most horrifying routine practices, like eye ablation — the removal of eyestalks to induce female shrimp to spawn. Because so many individual shrimp need to be killed to make one serving of food, even a small chance that they’re sentient convinced me to stop eating them. Plus, trawling for wild shrimp has the highest bycatch rate in the commercial fishing industry — more than half of the animals caught are discarded.

Individual versus systemic change is a false choice — we need both

But is individual dietary change the right thing to focus on, rather than systems-level change? This is a long-running debate on complex consumer issues like animal welfare and climate mitigation, but it’s always been an unhelpful binary. We need both. Many of the most effective animal welfare organizations focus on changing corporate and state actors to improve conditions for large numbers of animals at once. Reducing your own consumption of animal products also has a real, positive impact on animals and the environment. After accounting for bycatch and feed fish, the typical American is responsible for the deaths of between roughly 340 and 560 sea animals per year. That’s a lot of lives you could save by simply leaving fish off your plate.

Our individual choices can also have a social contagion effect — merely telling a recently converted pescetarian friend I was working on this piece convinced him to stop eating fish.

In recent years, animal advocates have begun to turn their attention to this long-ignored group and lobby for welfare reforms to how we farm and catch fish. Two new organizations are dedicated to improving the lives of the aquatic animals we eat: the Fish Welfare Initiative and the Aquatic Life Institute. This area is so neglected that there is a lot of low-hanging fruit, from changing tank color to reduce salmon aggression in farms to using more humane slaughter methods.

While writing this story, I’ve marveled at how much more fascinating and complex fish are than I originally thought. Our growing understanding of the sentience of other species has made it harder to identify ways in which humans are unique. Rather than diminish my view of humanity, this research motivates me to respect the unique preferences and experiences of nonhuman animals.

One area where I think humans remain unique is in our moral agency — our ability to make choices based on a notion of right and wrong. It’s uniquely human to construct massive industrial aquaculture operations and suffocate fish by the billions — but it’s also uniquely human to refuse to participate.

Garrison Lovely is a Brooklyn-based freelance journalist with work in BBC Future, New York Focus, Jacobin, and Current Affairs. He appeared on CBS News Sunday Morning and hosts the podcast The Most Interesting People I Know. He tweets from @garrisonlovely.