Pain and welfare - where do you stand?

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Pain and welfare - where do you stand?

As debates on whether fish feel pain continue to rage, Nathan Hill takes a look at some of the contentious topics currently doing the rounds.


In the time honoured tradition of bloggers and journalists the world over, I feel I’d be missing out if I didn’t open a piece on welfare by quoting Jeremy Bentham’s famous 1789 quote regarding what he saw as an important consideration when dealing with animals – "The question is not, Can they reason? nor, Can they talk? but, Can they suffer".

You’d imagine that a lot would rest on this somewhat salient point, and our attitudes towards animals over the last two centuries have certainly changed. Once held back by a mixture of Christian objection to nature worship, and an oddly intense obsession with the dignity of humans, where sympathy for animals was seen as somehow offensive, our collective mindset has shifted to appreciate that many animals are indeed individuals, capable of a life experience, and able to comprehend sensations that we would deem either positive or negative.

I am fortunate enough to find myself in possession of several scientific papers, arguing both for and against certain welfare practices that include fish. One of the joint authors of a seemingly hostile piece towards the feelings of livestock is a chap named Rose, alongside co-authors Diggles, Cooke and Sawynok.

Some readers may recognise the first name, as it was Rose who quite famously became a darling of the US angling industry when he published papers making the explicit claim that fishes were, in effect, nothing but unfeeling automatons, unable to feel what we would class as pain. This latter paper, Ecology and welfare of aquatic animals in wild capture fisheries by B.K.Diggles, S.J.Cooke, J.D.Rose, and W. Sawynok is the one I shall be focusing on, but it’s worth some background from earlier studies too, to see where some early contention lays.

After Rose’s former paper, separate research conducted in the UK offered a persuasive rebuttal to this mindset. Lynne Sneddon of the University of Chester performed numerous experiments into the pain perception of fishes, starting with the identification of nociceptors within fish.

For those unsure of what I mean by that, a nociceptor might also be considered a pain receptor. In us, it is the nociceptors that effectively ‘register’ damage to ourselves, be it physical or from noxious substances, and send messages through the nervous system and into the brain – where the brain registers the painful sensation and creates the accompanying emotional experience.

Lynne Sneddon’s research discovered nociception in fish, specifically in trout that were tested, via stimulating sedated fish and performing non invasive brain scans to find associated activity. After all, for anyone who sees brain activity and sensation as being the same thing – as most of us now do – activity in the brain of a nociceptor stimulated fish hinted strongly that there was an experience taking place – a ‘what it is like’ experience to having nociceptors stimulated.

However, nociception isn’t the end of the story. Not everyone accepts that nociception stimulation and pain sensation are the same thing. Through this loophole, the argument continues, and the nociception debate also leaves gaps in certain taxonomic branches. Elasmobranchs – the sharks and rays – have no discernible nociceptors, for example.

However, it doesn’t stop there. Further research indicates more than just nociception at play. It could be argued that even with nociceptors present, when a fish reacts to a stimuli, it is just that. A reflexive, unfelt reaction with little more than a cause/effect pattern. To be extremely crude, I might cite the mechanisms of certain plants that move when triggered by stimuli. There’s no reason at this time to think that the plants ‘feel’ anything, just that they react.

In fact, the paper from Diggles et al mentions this, stating in its introduction that “It is very important to differentiate between nociception and pain, because the latter depends on conscious awareness and always encompasses a felt emotional component, and the International Association for the Study of Pain (IASP) stresses that nociceptor activation is itself not pain.”

So research fell along the lines of showing that fish could learn to avoid painful stimuli, that they could develop a sense of aversion to something known to have previously hurt them. As crude as my oversimplification of this is, this is in effect what was shown. Fish did indeed learn to avoid painful procedures, and this in turn suggests a level, however primitive, of self awareness.

Ramifications for welfare

Here in the UK, we generally apply what are known as the Five Freedoms to living animals in (and to a lesser extent, outside of) our care. To recap, and to show those who may not have come across these five ‘f’s before, the freedoms are:

1. Freedom from Hunger and Thirst—by ready access to fresh water and a diet to maintain full health and vigour;

2. Freedom from Discomfort—by providing an appropriate environment including shelter and a comfortable resting area;

3. Freedom from Pain, Injury or Disease—by prevention or rapid diagnosis and treatment;

4. Freedom to Express Normal Behaviour—byproviding sufficient space, proper facilities and company of the animal’s own kind;

5. Freedom from Fear and Distress—by ensuring conditions and treatment which avoid mental suffering.

The freedoms seem rather obvious to most of us who care for our fish, and appeal to our sense of keeping our fish ‘happy’. However, Diggles’ paper criticises this approach as unrealistic to encompass the welfare of all animals – especially fish. Much of what the paper contains is of little relevance to us and our aquaria, related as it is to management of large scale fisheries, and large scale capture of wild caught fish, but some of the implications cannot be avoided, so I pick out some of the things that may cause contention.

The criticism of the Five Freedoms by Diggles et al is that they are a ‘feelings based’ approach, and one that centres on the ability of the animal in question to have actual feeling perceptions. For example, if an animal genuinely cannot feel pain (as we suspect most invertebrates cannot) then Freedom 5 has some difficulties.

Diggles’ paper goes on to state that "of course, it is impossible to determine what aquatic animals are feeling", and here he is correct, for sure. From a philosophical point of view, however, this is something of a bit of a non-starter.

Ultimately, it’s not possible to know exactly what anyone or anything feels. As experiments go, the task of being able to ascribe any sensation comes down to a study sample of just one – yourself. I will never know how pain feels for you, except by drawing on my own experience and applying it analogously. But that’s hardly any good.

Currently it sits outside the realm of all science for me to prove conclusively the experiential, personal and subjective element of sensation of any animal or any other person. All we can do is draw upon what evidence we have, and give benefit of the doubt where doubt exists.

Diggles’ paper makes a few more statements along a similar line, with “‘there is increased scientific acceptance that fish are able to feel fear, pain and distress’. However, empirical science is unable to prove that fish are capable of awareness”. Also mentioned is that, ‘‘benefit of the doubt’’ in this field of research has meant that because scientific proof that fishes or invertebrates can ‘‘feel pain’’ is lacking, it has become obligatory to assume that they can.”

Sweeping aside the ‘benefit of the doubt’ that fish might actually feel pain, the paper then goes on to make the most curious argument from nature – a school of thought that assumes that what is natural is somehow right, or inherently good. Specifically, early on it is mentioned that “Predation is the largest source of mortality of fishes and in the wild many millions of aquatic animals die every day from predation, mostly in what humans would consider to be the most inhumane circumstances (such as being cut in half, skewered or eaten and digested whole while still alive)”.

That’s not really contestable, as most fish do indeed meet the most horrific ends, but is it the right train of thought to take? Does it follow that if fish die horrifically in the wild, then the same mechanisms for their deaths can become ‘naturally justifiable’ for fish in our care?

Critics of this approach, Torgersen, Bracke and Kristiansen in their official reply to Diggles et al, state quite roundly that “we see little justification for our treatment of fish from the facts that fish treat each other in the most terrible of ways, and that disease and lethal, naturally occurring environmental challenges have massive negative effects on the quality of life of wild fish. If we are to act as moral beings, we cannot look to amoral creatures for ethical guidance. The moral questions (which are normative, not empirical-scientific ones) are whether we should allow ourselves to impose suffering on other subjects, and if so, how much and for what reasons.”

By way of alternative to a ‘feelings based’ approach to fish welfare, Diggles’ paper proposes a combination of a ‘function based’ as well as a ‘nature based’ approach to welfare considerations. In fact, Diggles’ paper has little love for the Five Freedom, ‘feelings based’ approach at all. It concludes, after attacking the idea, that “science must reject application of the feelings-based approach to aquatic animal welfare in the natural aquatic environment.” Ouch.

What Diggles’ paper lays out as the template for the ‘function based’ approach is pretty simple to follow, and not unfair. It holds that “In contrast to the feelings-based approach, the function-based approach to aquatic animal welfare focuses on the concept that good welfare requires that the aquatic animal is in good health with its biological systems (and particularly those involved in coping with challenges to stasis) functioning appropriately and not being forced to respond beyond their capacity.”

At face value this is reasonable, but the question now comes down to how one might feel about, say, battery chickens. They may be functioning perfectly well, but do we want something similar for our fish?

Recent videos suggest that some aquarists do take this approach. One only has to look at tanks barely larger than fish, with water pumped through remarkable sized filter systems, while the inhabitants are crammed in with other fish and unable to move, to realise that a fish can function on a remarkable small body of water.

Continuing, the function based approach given in Diggles’ paper also includes that it should also “ be based on behavioural, physiological, neurological, pathological and cellular criteria that are within the normal range for that organism, in full recognition that these criteria may vary”

So, in a nutshell, if it looks like a fish, is in good health, and functions the way a fish should, then there’s no ethical issue, according to this definition.

Also laid out is the ‘nature based’ approach. As Diggles’ paper puts it “For this definition, good welfare requires that the animal is able to lead a natural life and express its natural behaviour.”

Again, this seems fair at first, although we as aquarists may fall foul of this particular approach depending on which fish we keep. Certainly, those of us who opt for huge, migratory catfish have something of a quandary on our hands if not allowing our charges to carry out this biologically inherent and hardwired act.

But this is where the paper starts to make its argument from nature. Reference is made repeatedly to the huge volumes of fish predated by other fish, and then further references made to asphyxiation of fish through naturally occurring events (as well as human influence, I add).

In fact, the paper goes on to state – quite rightly, I feel – that predation plays a huge role in successful ‘natural management’ of natural bodies such as coral reefs. Further mention of mass mortalities follows, and then some rather muddied distinctions between fish as individuals, and fish as collectives, as part of the environment, as though management of the environment and treatment of the individual amount to the same thing.

However, these considerations are again the domain of other industries working with fish, and are of little concern to us as aquarium keepers.

The cause of my alarm comes during the final discussion in the paper. Opening with the line, “Humans have always been predators of animals, including fishes, and we never stopped being predators and part of the ancient food chain.”

Well, this is true, for sure, and this is hardly the right page to start exploring vegan ethics, but what follows from this rather bold statement?

Well, part of the writing is on the wall when Diggles et al sweep away once again the concerns of actual pain when they mention “the esoteric problems relating to the possibility of perception of ‘suffering’, ‘pain’ and ‘fear’ in invertebrates and ‘lower’ vertebrates,” as though such concerns, by virtue of their impossibility to prove, are of no worth.

In fairness to the paper, much of the reasoning is sound, especially where natural environments are concerned. The idea of the rejection of the feelings based approach in favour of function and nature, and when related to an ecosystem instead of an individual, does allow other factors to be incorporated into consideration – those of plankton, lower invertebrates, and even human impact, factors that the Five Freedoms do not account for directly.

However, the danger is that the argument could be used to prop unethical behaviour in aquaria, by those who translate the content as they wish. It would be dangerously easy to draw on the appeal to nature to argue for all sorts of cruel and barbarous things in the confines of tanks – and it’s worth remembering that fish in our aquaria are not in a natural environment. Fish removed from the wild and placed into the care of humans are suddenly, and quite instantaneously subjected to a whole new range of moral considerations – our own.

Lynne Sneddon of Chester University takes this latter stance in her own reply to the paper, where she says “Some authors misguidedly suggest that it is acceptable to treat fish in any way and have little or no regard for their wellbeing as we should consider ourselves as predators. However, natural predators only kill to satiate their hunger and stop once satisfied. To deliberately cause injury and suffering is unethical and as moral beings we have a duty of care to animals that we place in the completely unnatural environment . The scientific evidence that fish are capable of pain perception cannot be ignored and we must factor this into our treatment of fish regardless of the context.”

It would appear that the debate is polarising between those who have an empathic position towards other animals that can potentially suffer, and those who wish only for empirical evidence to the problems faced. Given the impossibility of ever empirically showing pain in fish, as mentioned earlier, it looks set to be a debate that may rage for some time.

We at PFK are keen to hear your views on the topic of pain and suffering. Do you think that we should allow empathy and give benefit of the doubt? Or do you prefer the empirical stance, working with what absolutes we have at this time?

To see some of the original texts, some of which can be found online, you’re looking for:

Sneddon L.U. (2011) Nociception or Pain in Fish. In: Farrell A.P., (ed.), Encyclopedia of Fish Physiology: From Genome to Environment, volume 1, pp. 713–719. San Diego: Academic Press.

Reply to Diggles et al. (2011): Ecology and welfare of aquatic animals in wild capture fisheries

Thomas Torgersen, Marc B. M. Bracke, Tore S. Kristiansen

Ecology and welfare of aquatic animals in wild capture fisheries

B.K.Diggles, S.J.Cooke, J.D.Rose, W. Sawynok

Of course, many more papers regarding this topic exist, and I’d invite you to read as many as possible.

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