Fish represent over 60% of all known vertebrate species on Earth. As many animals inhabit aquatic environments, it should be noted that throughout this report ‘fish’ refers to vertebrate finfish. This large group captures the bony fish (a group which comprises the vast majority of species, including familiar fish such as cod, bass and goldfish) and cartilaginous fish (a group which includes sharks and rays). The definition excludes aquatic mammals such as whales and dolphins, and all of the invertebrates, including crustaceans (e.g. lobsters and crabs), shellfish (e.g. mussels and oysters), cephalopods (e.g. octopuses and squid), and echinoderms (e.g. starfish and sea urchins). The most recent assessment of fish diversity documented 33,249 species, 564 families and 64 orders. Of these, over 31,000 species are classified as bony fish.
One of the most populous and diverse animals on the planet, fish are routinely exploited for human use and consumption, with fish welfare remaining a relatively unexplored concept, both scientifically and politically. Indeed, while legislation on the protection of animal welfare is increasingly implemented in countries around the world, since the introduction of ‘Martin’s Act’ in England in 1822, fish remain largely ignored or are expressly excluded from the legal protections afforded to mammals, birds and other vertebrates.
The tendency to exclude fish from welfare considerations is, in part, because debates that were largely laid to rest with regard to the sentience of mammals and birds continue to rumble on when it comes to fish. There has long been global acceptance that mammals and birds are sentient (i.e. they have the capacity to suffer and can experience both pleasure and pain) and it is this fact that gives rise to our moral obligation towards them. In short, these animals are understood to possess welfare needs which should be protected if they are to avoid suffering. This, in turn, gives rise to the ever-expanding global body of legislation which seeks to protect animal welfare and prevent unnecessary suffering.
Despite fish possessing similar physiology to mammals and birds, their capacity to suffer was ignored, avoided or actively rejected until very recently.
Those who argued that fish were not sentient based their position on the fact that fish do not possess a neocortex, the part of the mammalian brain that deals with emotion, sensory perception and cognition. This argument is Cartesian in its foundation, asserting that while it can be recognised that fish may react physically to injury or damage, this reaction is merely an unconscious response to external stimuli (known as nociception). For an animal to be considered capable of experiencing pain (and associated suffering), the argument goes, response to injury or damage must be more complex than mere unconscious reaction and must include a conscious awareness of the painful experience.
Based on the absence of a neocortex in fish, Rose et al, in the 2012 paper, ‘Can Fish Really Feel Pain?’, concluded that: ‘overall, the behavioral and neurobiological evidence reviewed shows fish responses to nociceptive stimuli are limited and fish are unlikely to experience pain’. As Balcombe notes, however, birds do not possess a neocortex either and yet were recognised as being sentient long before Rose’s 2012 paper. Importantly, birds have also long been afforded legal protection based on indisputable evidence of their sentience. Notwithstanding the dubious view that a neocortex is required for an individual to experience suffering, thorough research published almost a decade prior to Rose et al had already explored the specific issue of fish sentience, and drawn compelling conclusions.
In 2003, the publication of a paper by Victoria Braithwaite et al caused waves in the scientific community. Their research sought to prove whether or not fish could feel pain and, if so, whether their experience was merely an unconscious reaction to injurious stimuli or could be truly indicative of the conscious experience required for the capacity to suffer.
Braithwaite et al’s research corroborated earlier findings by Russian scientist, Chervova, demonstrating that fish have the requisite physical anatomy to feel pain, react consciously to painful stimuli and demonstrate evidence of suffering as a result of pain being inflicted. This evidence of the high cognitive functioning required to demonstrate sentience, coupled with the proof of conscious, prolonged reactions to painful stimuli, effectively debunked the assertion that a neocortex was necessary to experience pain. It also provided clear evidence that fish certainly do have the capacity to suffer.
By proving that fish can and do suffer, Braithwaite’s work opened up discussion in both public and political spheres on the putative human obligation to protect fish from suffering.
Since the publication of Braithwaite et al’s work, an increasing body of evidence has shown that fish are not just sentient but that some species demonstrate tool use and cooperation with others, including interspecies cooperative hunting (previously attributed to very few animals, all of which were considered far more cognitively advanced than fish, such as dolphins and false killer whales). They also exhibit complex social skills and even self-awareness, a high-functioning cognitive trait previously only attributed to humans, great apes and some cetaceans (dolphin and whale species).
Although slow, progress is nonetheless being made, with the plight of fish gradually becoming the subject of both political and public interest. Research carried out by the European Food Safety Authority (EFSA) and published as a series of reports in 2008 and 2009, considered the need for welfare provision for fish, not just in the interests of the fish themselves but also for food safety reasons. This research resulted in a series of detailed, species-specific reports, which considered inter alia, welfare during husbandry and at the time of slaughter. The work highlighted the higher occurrence of potentially dangerous pathogens in fish not afforded adequate welfare provision, explored the impact of stress on farmed fish, and reviewed the range of factors in aquaculture that can impact on welfare.
EFSA’s research in turn triggered the publication of a 2009 statement by the European Commission, acknowledging that: ‘there is now sufficient scientific evidence indicating that fish are sentient beings and that they are subject to pain and suffering’.
Despite burgeoning evidence that fish have welfare needs, and some moves in the political sphere to recognise that fact, legal protection for fish remains far behind that of other animals. This is of significant concern, not just from an ethical perspective but because fish are by far the most exploited animal on earth.
Evidence of the extent to which fish may suffer is still limited, albeit expanding, and the research that does exist focuses on very few species. Caution must be exercised, therefore, when speculating as to how that suffering may be experienced (for example, its intensity in comparison to mammal or bird suffering), or the specific preferences and needs of different fish species. However, Eurogroup for Animals believes that, given the compelling evidence of suffering among those fish species examined (including many who are commonly bred and captured for human consumption), a range of specific protections are well-founded and clearly justified. Elsewhere, Eurogroup for Animals argues that a precautionary principle should be employed to ensure that fish are adequately protected by law from unnecessary suffering in the aquaculture and fisheries industries.
Douglas Waley is the Fish Welfare Programme Leader at Eurogroup for Animals (Eurogroup) and supports Eurogroup’s Fish Working Group. Eurogroup has published a report on fish welfare, described in this article.