“When humans are in pain, we do other tasks less well. “Stimuli that would cause pain to us also affect fish,” said Sneddon. When Sneddon’s team gave trout an injection of acetic acid or bee venom – both of which cause pain in humans – the fish began breathing faster and rubbed the injection site on gravel.
Putting the hardware and software together and watching behaviour in experiments creates strong evidence. In humans these are involved in pain, hunger, thirst and fear, and include opiate-like chemicals that reduce pain. Mammals and fish share many identical neurotransmitters including dopamine and serotonin. The software to match this comes in the form of brain chemicals called neurotransmitters. Nerves are not proof that fish experience pain – but Sneddon showed that fish have the necessary hardware. “My research has shown that fish have a strikingly similar neuronal system to mammals,” she told me, adding that until 2002, “it was generally believed fish did not have feelings”. Sneddon showed that pinching and pricking fish activates these nerve fibres. In 2002, she identified in fish the same nerve types that, in humans, detect painful stimuli. Lynne Sneddon, director of bioveterinary science at Liverpool University, was the first scientist to discover that fish possess nerves known to convey pain. Yet by examining fish brains and behaviours, then comparing them to a species universally acknowledged to feel pain and pleasure – humans – we can look for clues.įish were ancestors to all other vertebrates their brains were the template for our own brains’ evolution. Yes, my fish jerked from the hook’s jab, but that could be merely reflexive. Brains offer only circumstantial evidence. Trying to catch just one wild fish, I have time to consider all the implications.Ī sking whether fish suffer means asking whether fish possess the ability to feel at all. In an essay titled Fish Intelligence, Sentience and Ethics, the Australian researcher Culum Brown suggests that the sheer scale of the global fishing industry makes the idea of legislating for the humane treatment of fish “too daunting to consider”.īut I do not have that excuse. Compared to those, pain and fear are primitive and basic.Īlthough aquatic farms in a handful of countries, including the UK and Norway, must follow humane slaughter guidelines, there are no standards for considering the tens of thousands of wild fish caught every second. Research has shown that various fish show long-term memory, social bonding, parenting, learned traditions, tool use, and even inter-species cooperation. When you are a fish, no one can hear you scream.įish have honed their skills for hundreds of millions of years humans are just making their acquaintance. To human sensibilities, their grunts do not sound like growling, or screaming – but what if they are just that? Even when we hear them, we don’t hear them. Sea-robins have often grunted when I have caught one. When I was a child on Long Island, I would hear toadfish croaking through the thin hull of my aluminum rowboat. I have devoted my career to conservation and to fish as wild animals. Key’s essay triggered more than three dozen opposing scientific responses, pressing new evidence that fish are aware of pain, of anxiety, of pleasures.Ī diver and a dusky grouper off Corsica in the Mediterranean. Now he argued thus: mammals feel things, and only mammal brains have a structure called the neocortex ergo fish, lacking a neocortex, feel nothing.īut that is like saying that because we travel using legs, then fish, who have no legs, cannot travel. Key had earlier written that “it doesn’t feel like anything to be a fish”. In 2016, the journal Animal Sentience published Australian neuroscientist Brian Key’s essay Why Fish Do Not Feel Pain. It is a question dividing the science community forced to reassess in light of new evidence.
The ethics of all this depend on what fish do or do not experience. Up to 2.7tn wild fish are caught worldwide every year a third of which are ground into feed for chickens, pigs and other fish. Angling, the so-called “gentle art”, derives enjoyment from the struggles of its quarry. The impression that fish are insensate, short of memory and, therefore, can be caught, killed and eaten without guilt, is being revisited.