Such logic is still prevalent today. In 2014, BBC Newsnight<\/em> invited Penn State University biologist Victoria Braithwaite to discuss fish pain and welfare with Bertie Armstrong, head of the Scottish Fishermen\u2019s Federation. Armstrong dismissed the notion that fish deserve welfare laws as \u201ccranky\u201d and insisted that \u201cthe balance of scientific evidence is that fish do not feel pain as we do.\u201d<\/p>\n Despite the evidence that fish can suffer, animal welfare legislations and other legal protections often exclude them. Photo by Juniors Bildarchiv GmbH\/Alamy Stock Photo<\/p><\/div>\n That\u2019s not quite true, Braithwaite says. It is impossible to definitively know whether another creature\u2019s subjective experience is like our own. But that is beside the point. We do not know whether cats, dogs, lab animals, chickens, and cattle feel pain the way we do, yet we still afford them increasingly humane treatment and legal protections because they have demonstrated an ability to suffer. In the past 15 years, Braithwaite and other fish biologists around the world have produced substantial evidence that, just like mammals and birds, fish also experience conscious pain. \u201cMore and more people are willing to accept the facts,\u201d Braithwaite says. \u201cFish do feel pain. It\u2019s likely different from what humans feel, but it is still a kind of pain.\u201d<\/p>\n At the anatomical level, fish have neurons known as nociceptors, which detect potential harm, such as high temperatures, intense pressure, and caustic chemicals. Fish produce the same opioids\u2014the body\u2019s innate painkillers\u2014that mammals do. And their brain activity during injury is analogous to that in terrestrial vertebrates: sticking a pin into goldfish or rainbow trout, just behind their gills, stimulates nociceptors and a cascade of electrical activity that surges toward brain regions essential for conscious sensory perceptions (such as the cerebellum, tectum, and telencephalon), not just the hindbrain and brainstem, which are responsible for reflexes and impulses.<\/p>\n Fish also behave in ways that indicate they consciously experience pain. In one study, researchers dropped clusters of brightly colored Lego blocks into tanks containing rainbow trout. Trout typically avoid an unfamiliar object suddenly introduced to their environment in case it\u2019s dangerous. But when scientists gave the rainbow trout a painful injection of acetic acid, they were much less likely to exhibit these defensive behaviors, presumably because they were distracted by their own suffering. In contrast, fish injected with both acid and morphine maintained their usual caution. Like all analgesics, morphine dulls the experience of pain, but does nothing to remove the source of pain itself, suggesting that the fish\u2019s behavior reflected their mental state, not mere physiology. If the fish were reflexively responding to the presence of caustic acid, as opposed to consciously experiencing pain, then the morphine should not have made a difference.<\/p>\n In another study, rainbow trout that received injections of acetic acid in their lips began to breathe more quickly, rocked back and forth on the bottom of the tank, rubbed their lips against the gravel and the side of the tank, and took more than twice as long to resume feeding as fish injected with benign saline. Fish injected with both acid and morphine also showed some of these unusual behaviors, but to a much lesser extent, whereas fish injected with saline never behaved oddly.<\/p>\n Testing for pain in fish is challenging, so researchers often look for unusual behavior and physiological responses. In one study, rainbow trout given injections of acetic acid in their lips responded by rubbing their lips on the sides and bottom of their tank and delaying feeding. Photo by Alex Mustard\/2020Vision\/Minden Pictures<\/p><\/div>\n Several years ago, Lynne Sneddon, a University of Liverpool biologist and one of the world\u2019s foremost experts on fish pain, began conducting a set of particularly intriguing experiments; so far, only some of the results have been published. In one test, she gave zebrafish the choice between two aquariums: one completely barren, the other containing gravel, a plant, and a view of other fish. They consistently preferred to spend time in the livelier, decorated chamber. When some fish were injected with acid, however, and the bleak aquarium was flooded with pain-numbing lidocaine, they switched their preference, abandoning the enriched tank. Sneddon repeated this study with one change: rather than suffusing the boring aquarium with painkiller, she injected it straight into the fish\u2019s bodies, so they could take it with them wherever they swam. The fish remained among the gravel and greenery.<\/p>\n The collective evidence is now robust enough that biologists and veterinarians increasingly accept fish pain as a reality. \u201cIt\u2019s changed so much,\u201d Sneddon says, reflecting on her experiences speaking to both scientists and the general public. \u201cBack in 2003, when I gave talks, I would ask, \u2018Who believes fish can feel pain?\u2019 Just one or two hands would go up. Now you ask the room and pretty much everyone puts their hands up.\u201d In 2013, the American Veterinary Medical Association published new guidelines for the euthanasia of animals, which included the following statements: \u201cSuggestions that finfish responses to pain merely represent simple reflexes have been refuted. \u2026 the preponderance of accumulated evidence supports the position that finfish should be accorded the same considerations as terrestrial vertebrates in regard to relief from pain.\u201d<\/p>\n Yet this scientific consensus has not permeated public perception. Google \u201cdo fish feel pain\u201d and you plunge yourself into a morass of conflicting messages. They don\u2019t, says one headline. They do, says another. Other sources claim there\u2019s a convoluted debate raging between scientists. In truth, that level of ambiguity and disagreement no longer exists in the scientific community. In 2016, University of Queensland professor Brian Key published an article titled \u201cWhy fish do not feel pain\u201d in Animal Sentience: An Interdisciplinary Journal on Animal Feeling<\/em>. So far, Key\u2019s article has provoked more than 40 responses from scientists around the world, almost all of whom reject his conclusions.<\/p>\n Key is one of the most vociferous critics of the idea that fish can consciously suffer; the other is James D. Rose, a professor emeritus of zoology at the University of Wyoming and an avid fisherman who has written for the pro-angling publication Angling Matters<\/em>. The thrust of their argument is that the studies ostensibly demonstrating pain in fish are poorly designed and, more fundamentally, that fish lack brains complex enough to generate a subjective experience of pain. In particular, they stress that fish do not have the kind of large, dense, undulating cerebral cortices that humans, primates, and certain other mammals possess. The cortex, which envelops the rest of the brain like bark, is thought to be crucial for sensory perceptions and consciousness.<\/p>\n Some of the critiques published by Key and Rose are valid, particularly on the subject of methodological flaws. A few studies in the growing literature on fish pain do not properly distinguish between a reflexive response to injury and a probable experience of pain, and some researchers have overstated the significance of these flawed efforts. At this point, however, such studies are in the minority. Many experiments have confirmed the early work of Braithwaite and Sneddon.<\/p>\n Moreover, the notion that fish do not have the cerebral complexity to feel pain is decidedly antiquated. Scientists agree that most, if not all, vertebrates (as well as some invertebrates) are conscious and that a cerebral cortex as swollen as our own is not a prerequisite for a subjective experience of the world. The planet contains a multitude of brains, dense and spongy, globular and elongated, as small as poppy seeds and as large as watermelons; different animal lineages have independently conjured similar mental abilities from very different neural machines. A mind does not have to be human to suffer.<\/p>\n Despite the evidence of conscious suffering in fish, they are not typically afforded the kind of legal protections given to farm animals, lab animals, and pets in many countries around the world. The United Kingdom has some of the most progressive animal welfare legislation, which typically covers all nonhuman vertebrates. In Canada and Australia, animal welfare laws are more piecemeal, varying from one state or province to another; some protect fish, some don\u2019t. Japan\u2019s relevant legislation largely neglects fish. China has very few substantive animal welfare laws of any kind. And in the United States, the Animal Welfare Act protects most warm-blooded animals used in research and sold as pets, but excludes fish, amphibians, and reptiles. Yet the sheer number of fish killed for food and bred for pet stores dwarfs the corresponding numbers of mammals, birds, and reptiles. Annually, about 70 billion land animals are killed for food around the world. That number includes chickens, other poultry, and all forms of livestock. In contrast, an estimated 10 to 100 billion farmed fish are killed globally every year, and about another one to three trillion fish are caught from the wild. The number of fish killed each year far exceeds the number of people who have ever existed on Earth.<\/p>\n \u201cWe have largely thought of fish as very alien and very simple, so we didn\u2019t really care how we killed them,\u201d Braithwaite says. \u201cIf we look at trawl netting, that\u2019s a pretty gruesome way for fish to die: the barometric trauma of getting ripped from the ocean into open air, and then slowly suffocating. Can we do that more humanely? Yes. Should we? Probably, yes. We\u2019re mostly not doing it at the moment because it\u2019s more expensive to kill fish humanely, especially in the wild.\u201d<\/p>\n![\"a](\"https:\/\/hakaimagazine.com\/wp-content\/uploads\/goldfish-fish-feel.jpg\")
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