DO FISH FEEL IT?

In the popular CBS television series Judging Amy, there is an episode in which Amy’s daughter, Lauren, tells her mother that she has become a vegetarian. Later we see the family eating dinner. Amy has cooked, and she tells Lauren, ‘It’s ravioli. There’s no meat.’ It turns out, however, that the dish contains shrimp. Lauren is furious, saying that her mother has been trying to trick her. Amy replies, ‘Shrimp is not meat,’ and adds, ‘A lot of vegetarians eat seafood.’ For many vegetarians, that episode will have struck a familiar chord. It happens so often: you walk into a restaurant and ask what vegetarian options they have and they start telling you about their fish. It’s true that some people who call themselves vegetarians do eat seafood, although that is neither the original nor the most usual meaning of the word. Mary Ann’s comment that a fish lacks the sensitivity of a cow or other mammal probably sums up the reasons of many for drawing a line between meat and fish, shrimps or oysters.

Indifference to the suffering of fish is widespread even in societies where most people show some concern for animals. Otherwise, how could people who would be horrified at the idea of slowly suffocating a dog enjoy spending a Sunday afternoon sitting on a riverbank dangling a barbed hook into the water, hoping that a fish will bite and get the barb caught in its mouth—whereupon they will haul the fish out of the water, remove the hook, and allow it to flap around in a box beside them, slowly suffocating to death? Is it because the fish is cold and slimy rather than warm and furry? Or that it cannot bark or scream? Or is it because Mary Ann and people who fish are justified in believing that fish are not nearly as sensitive as mammals?

Reviews in Fisheries Science is an obscure journal that rarely gets noticed by anyone outside a narrow circle of scientists specialising in fisheries. But when, in 2002, James Rose, a professor of zoology and physiology at the University of Wyoming in Laramie, published in its pages a review of what we know about the brains of fish and concluded that fish cannot feel pain, his findings were reported around the world. Awareness of pain, he claimed, requires activity in very specific regions of the cerebral hemispheres—regions that fish, because of their different evolutionary history, do not possess. Fish do have nervous systems that enable them to respond to noxious, tissue-damaging stimuli that would be painful in us, but these reactions, Rose said, do not imply consciousness.⁴¹ Anglers, not surprisingly, welcomed that conclusion.

Rose’s view did not go uncontested. The following year Proceedings of the Royal Society, the journal of one of the oldest and most respected scientific bodies in the world (Sir Isaac Newton once served as its president) published an article by Dr Lynne Sneddon and other scientists at the Roslin Institute and the University of Edinburgh. Sneddon and her colleagues injected bee venom and acetic acid into the lips of captive rainbow trout and found that they rubbed their lips into the gravel at the bottom of their tank and performed a rocking motion that is common in mammals who appear to be in pain. Other fish, in a control group, had only salt water injected into their lips and did not show the same behaviour. In general, the researchers said, the trout showed ‘profound behavioural and physiological changes…comparable to those observed in higher mammals’. These changes went far beyond simple reflex responses. Moreover, when the fish were given morphine, they resumed feeding, as one might expect them to do if they had been in pain and the drug relieved the pain. The researchers concluded that ‘fish can perceive pain’.⁴²

That view was supported by several other scientists, including Dr Culum Brown of the University of Edinburgh. Brown considers it a mistake to think of evolution as a straightforward progression from simple, primitive animals to more complex, cognitively superior ones. Fish have existed for vastly longer than there have been human beings, but they did not cease to evolve when our ancestors moved onto dry land. As a result, Brown says, ‘The structure of the fish brain is varied and rather different from ours, yet it functions in a very similar way.’

Remember the myth, given new currency in the popular movie Finding Nemo, that a goldfish has only a three-second memory? Brown’s own research has proved that the Australian freshwater rainbowfish, at least, does considerably better. He trained them to find a hole in a net. They needed about five attempts to learn where the hole was and locate it reliably. Then he took the net away for 11 months—the equivalent, in terms of their usual lifespan, to at least 20 years for a human being. When the net was returned, the fish did not need to re-learn where the hole was—they were able to find it as rapidly as they had before it had been removed. Brown points to many other impressive cognitive feats that fish can perform, including learning from observing other fish, cooperating to catch food, and knowing their relative social rankings in a group of fish, much as chickens learn a ‘pecking order’. In Brown’s view, ‘we must reverse hundreds of years of prejudice’ before people will appreciate that fish are intelligent. ‘Fish may seem quite pathetic when they are flopping around on the deck of a boat,’ he writes, ‘but get down into their world and you’ll soon realise that they are remarkable creatures.’⁴³

We agree. As Sneddon and her colleagues have shown, fish behave as if they are in pain, and this behaviour seems purposive, directed at relieving the pain—it is not merely a reflex response. We consider that Sneddon’s work has, for all practical purposes, shown that fish do feel pain.

The Harm of the Harvest

In addition to the environmental concerns involved, farmed fish, like Mary Ann’s salmon, could suffer welfare problems similar to those of intensively farmed chicken. The fish are very densely stocked, which forces them to crowd much more closely than they would in a natural school. In a handbook for fish farmers, S. D. Sedgwick writes:

Salmon are animals genetically programmed to spend most of their lives swimming freely through the oceans. We now confine them in tanks or cages in close proximity and frequent physical contact with thousands of others. In the open seas they would probably never have come as close to any other fish of their own kind before returning to spawn.⁴⁴

Thirty years of breeding salmon for farming have done little to change their instincts. In a manner reminiscent of the endless pacing of tigers in small bare zoo cages, farmed salmon typically swim as a school in circles around their cage. This seems to be a response to their inability to act on their instincts.

Large fish will bully and sometimes eat small fish. To stop this, as farmed fish grow they are sorted for size, so that the faster-growing ones are separated from the slower-growing fish. The sorting takes place between three and five times during the rearing process and involves netting or pumping the fish out of their cage so that they drop through a series of bars that only allow progressively smaller fish through. The sorting adds to the stress endured by the salmon. In general, their crowded confinement gives rise to stress, abnormal behaviour, sea lice infestations, abrasions, and a high death rate. Those that survive the rearing process are normally starved for 7–10 days before slaughter, to empty the gut and reduce the risk of contamination of the flesh when the fish is gutted. Any conscious being suddenly used to receiving plenty of food at frequent intervals will suffer if the food is suddenly cut off.

Then comes slaughter. There is generally no requirement for stunning or humane slaughter of fish, so they are killed in brutal ways that would be illegal and shocking if used on cows or pigs. Farmed fish may simply be allowed to suffocate in the air. It can take 15 minutes for them to die by this method. Large fish like salmon may be bashed on the head with a wooden bat, which does not always kill them outright and may just leave them injured, to be cut open while fully conscious. Or they may be stunned by the use of carbon dioxide in the water. This causes them to thrash about for half a minute, after which they stop moving but do not lose consciousness for several more minutes. They then have their gills cut and bleed to death. It is possible that they are conscious during this process.⁴⁵

Wild-caught fish have one great advantage over farmed fish, and, for that matter, over all farmed animals. Until their final hours they live their entire lives free of human interference or confinement. This may be the best reason for thinking it to be more ethically defensible to eat fish than to eat meat. The other side of the coin, though, is that there is no such thing as humane slaughter for wild-caught fish. Each year, hundreds of millions of fish are hooked on longlines—as much as 75 miles (120 km) of line, with baited hooks at frequent intervals—that are dragged behind commercial fishing boats or left in the water overnight. Once hooked, swordfish and yellowfin tuna weighing hundreds of pounds will struggle for hours trying in vain to escape. Then they are hauled in, and as they come up to the boat, fishers sink pickaxes into their sides to pull them aboard. They are clubbed to death, or have their gills cut and bleed to death.

Gill nets are another common form of commercial fishing. These nets, which can be up to a mile long, are left drifting in the sea, the top attached to floats, the bottom weighted down. The nets take advantage of the streamlined body shape of the fish, which swim into them and then are caught by the gills or fins, unable to back out. Some struggle so violently they injure themselves and bleed to death. Others remain trapped, perhaps for days, until the boat returns and hauls in the net. Then they will have their gills cut and will bleed to death, or may be left to flap helplessly on the deck as they suffocate. In bottom trawling, as we have seen, a net is dragged along the bottom of the sea, gathering up everything in its path. Fish caught in the net will be dragged along for hours, squeezed against the wall of the net by everything else that it gathers up, including rocks, pieces of coral, and other fish. Their scales may be ground off by this process. If they are still alive when the net is hauled up, those that live in deep waters may die from decompression, their swimbladders ruptured, their stomachs forced out of their mouths and their eyes bulging from their sockets. The remainder will suffocate in the air. On factory ships that begin processing immediately, they may be cut up while they are still alive.

When we turn to shrimps, crabs and lobster, there is more room for doubt about the capacity to feel pain than there is with fish, given the absence of a prominent brain. What is the right ethical response to such a state of uncertainty? Suppose you are driving your car along a narrow two-lane road on a dark night and you see something in the road, across your lane. It may be a bundle of old clothes, but it might also be a person. Should you just drive over it, swerve around it, or stop? Obviously, if you can safely stop, that is what you should do. But suppose the road is icy, there is a car close behind you and a car coming the other way. In such circumstances you can’t swerve, and if you hit the brakes hard you may be hit by the car behind, causing a serious accident. Then, if the object on the road is very likely to be just a bundle of old clothes, it may be right to drive over it, hoping that it isn’t a person, or at least not a living one.

As this example shows, if there is uncertainty about whether what we do will cause serious harm, we should give the benefit of the doubt to the being whom we might harm. But exactly what ‘giving the benefit of the doubt’ requires will depend on both the extent of the doubt and the costs of acting so as to make certain we don’t cause harm. Similarly, if we are uncertain whether lobster, crabs and shrimp feel pain, we should give them the benefit of the doubt and treat them as if they are capable of suffering, as long as the costs of doing so are not too high. If we are uncertain that they can feel pain, we should try to avoid doing anything that risks inflicting pain on them. On the other hand, if it were a choice between causing them possible pain or incurring great suffering ourselves, we would be justified in no longer giving them the benefit of the doubt—though we should still do our best to minimise the pain we might be inflicting on them.

If these invertebrates can feel anything, the way they are farmed, caught and killed must inflict severe pain on them. As anyone who has walked past seafood markets knows, lobsters and crabs are often kept alive in buckets or even just piled up in a basket, with their claws tied together, for long periods. Then they are killed by being boiled alive. If shrimp can feel pain, since it takes many of them to make a meal, the suffering in every plate of shrimp could be proportionally greater than for a larger animal. For anyone who has other food choices, it cannot be ethically justifiable to risk supporting the infliction of such agony on living creatures who may be able to feel pain.

All of the issues we have just discussed regarding fish and crustacea can be raised about molluscs, which range from animals like octopus and squid, who have complex brains and an amazing ability to learn new tasks, like opening jars with their tentacles, to immobile bivalves like oysters. It is hard to explain what an octopus can do without assuming consciousness, but with the bivalves, the evidence for consciousness is barely stronger than it is in plants, which is to say it is vanishingly slight. Ethical arguments against eating animals that are based on not causing—or not risking causing—suffering therefore get little grip on eating oysters, clams and scallops, but are applicable when it comes to eating octopus and squid.

To Eat, or Not to Eat?

Despite the widespread view that eating seafood is somehow less ethically problematic than eating birds or mammals, finding seafood that is environmentally sustainable is not easy. Jake happened upon fish from a sustainable fishery, but Mary Ann, who pays more attention to environmental issues in her food choices than most people, chose Norwegian salmon, an intensively farmed fish that pollutes the fjords in which it is farmed, spreads parasites to wild salmon, and, because it must eat fish meal, requires fishing fleets to catch three times a salmon’s own weight in fish. The Venezuelan shrimp Mary Ann bought may or may not have been farmed in a way that avoids damaging its local environment, but it will still have had to be fed from fish taken from the oceans, so it is a dubious environmental choice at best.

Of Mary Ann’s three choices, only the Maryland (or Virginia) blue crab seems to have been an environmentally good choice. With the aid of an up-to-date list from Oceans Alive or Seafood Watch, it may be possible to choose sustainable seafood—although there is still the problem of fraudulent labelling of fish as ‘wild’ when it is in fact farmed. If we add to the environmental issues the ethical obligation to avoid causing unnecessary suffering to beings who are, or may be, capable of feeling pain, it begins to seem better, as well as simpler, not to buy seafood at all, with the exception of sustainably obtained simple molluscs like clams, oysters and mussels.