Do Fish Feel Pain?

For those of us who base our total or partial vegetarianism on the ethical principle of not inflicting suffering on animals who are capable of suffering, one question deserves to be asked but is frequently relegated to the realm of "ignorance is bliss": Do fish feel pain?

In April, Oxford University Press published Do Fish Feel Pain? by animal welfare scientist Victoria Braithwaite. Many people think the answer to that question is obvious, but depending on whom you ask, that "obvious" answer varies considerably. For once, we have a credible book that attempts to answer that question with science.

Braithwaite explains why it's only been in the last decade that scientists have made headway in answering the fish pain question. She distinguishes between nociception, which is the unconscious detection of adverse stimuli by the body, and pain, which is processed by the brain and felt as suffering at an emotional level. Braithwaite discusses fish consciousness, sentience, and brain anatomy, and while she is hesitant to declare a definitive answer, she concludes, "I believe the weight of evidence now shows fish do feel pain."

Braithwaite invites bioethicists to have this revelation inform their discussions, but she does not go so far as to call for an end to fish consumption, angling, or other uses of fish. Quite logically, though, she does put the matter into perspective:

The issues and the evidence are not always black and white, which makes pain in animals a difficult topic with tricky ethical and philosophical implications. However, if we already accept that mammals and birds are sentient creatures that have the capacity to experience positive and negative emotions--pleasure or suffering, we should conclude that there is now sufficient evidence to put fish alongside birds and mammals. Given all of this, I see no logical reason why we should not extend to fish the same welfare considerations that we currently extend to birds and mammals.

One of the highlights of the book is the compelling descriptions Braithwaite offers with regard to commercial fishing. In general I've found it hard to feel sympathy for fish, since they appear to be so different than other vertebrate animals. But if you truly accept the notion that fish are sentient creatures who feel pain, then it's hard not to be appalled by some commercial fishing practices that Braithwaite describes:

• "Long-lining fishing catches species such as tuna, swordfish, and mahi mahi. Long-lining crews set up several hundred lengths of line that can be tens of metres long. The lines, rigged with floats and hundreds of baited hooks, are left for several hours at a specific depth in the water to attract hungry fish species. Once hooked, depending on the number of lines set, the fish may have up to 10 hours to wait before they are collected in. Many fish are exhausted from trying to escape, but they are still alive as they are hauled onto the deck of the fishing vessel and then left to suffocate in the air."
• "As the trawl net [a massive net that captures all target fish and other marine animals in its path] moves up through the water column the rapid changes in pressure cause problems for the fish. ... Without time to adjust to the decreasing pressure [of being dragged toward the surface while stuck in the trawl net], the gas-filled swim bladder typically becomes overinflated, causing huge distention inside the fish. Sometimes the pressure is so great their stomach and intestines are pushed out of their mouth and anus. Eyes can also become distorted and bulge out."

Frankly, that kind of suffering seems worse than just about any other in industrialized animal agriculture. If people eat fish and otherwise follow a vegetarian diet for ethical reasons, they might wish to consider the evidence in Do Fish Feel Pain? and take their admirable ethical position to its logical conclusion. If people eat "wild-caught" fish and think that they're sparing fish and the environment from any perils, they might want to take a closer look at the situation. I concede that my decision not to eat fish has at times been based more on routine, consistency, and idealism than on certainty in my convictions, but now it's hard to imagine ever eating fish again.