Isn’t it infuriating to come up against someone who argues that fish don’t feel pain but that plants do?! Obviously, plants don’t feel pain — they don’t have central nervous systems, nerve endings or brains — but if they did, that would be another argument in favour of veganism, as vegans actually consume fewer plants than the farmed animals that omnivores eat.
And as for fish, there is plenty of scientific evidence to show that fish do feel pain. First, they have pain receptors, which would be strange if they weren’t able to feel pain. Moreover, they produce substances known as enkephalins that mediate pain in the same way that they do in vertebrates like you and me.
The second way scientists determine that a species can feel pain is to observe whether they behave as though they feel pain. There has been much research, much of it pretty unpleasant (which we do not support but we cite to illustrate the point), that has shown that aquatic species have an aversion to noxious substances.
Scientists also found that crabs will trade a great hiding place for a mild electric shock but abandon it for an inferior place should the shock be increased. And, like us when we bang a limb and rub the affected area, prawns rub their antennae when they have been pinched with forceps.
Since no one knows for sure if anyone other than themselves can feel pain in the same way they do, scientists rely on these two criteria to determine whether fish can feel pain. The answer to ‘do they have the necessary equipment to do so?’ is ‘yes’, and the answer to ‘does their behaviour suggest they do?’ is ‘yes’ again.
Despite this, farmed fish have very few legal protections and wild-caught fish have none at all. Billions of these sentient beings are hauled out of the water and left to asphyxiate in the air, or are crushed under tonnes of their shoal mates. If welfare regulations relating to the treatment of wild-caught fish were introduced, the trade would end overnight because there is no humane way to catch and ‘dispatch’ that number of fish.
Farmed fish fare little better. Shrimps and prawns, for example, are deliberately blinded because those reared in captivity often aren’t able to reproduce, and having their eyestalks cut off triggers the maturing of their ovaries. Eyestalk ablation, as it is called, has been labelled ‘cruel’ and ‘traumatic’ by numerous scientists but it won’t stop – it is an intrinsic part of shrimp farming and more than half of all shrimps consumed globally are farmed.