Nyere forskning tilsier at fisk føler og oppfatter smerte. Dette har også vært lagt til grunn i norsk dyrevernlov siden 1974. Likevel er det fortsatt enkelte som stiller spørsmål ved om fisk opplever lidelse når den skades, er syk eller utsettes for brutal behandling.

Fagartikkel av Susanna Lybæk, zoolog og fagrådgiver i Dyrevernalliansen

I det følgende oppsummeres sentral forskning, litteraturstudier og utredninger som taler for at fisk bør vernes mot å bli påført smerte av mennesker.

Mejdell, C., Fisk og smerteoppfattelse, Norsk Veterinærtidsskrift 110, 8/9, Brev til redaktøren, s. 540, 1998:
"De strukturelle homologiene indikerer at fisk ikke bare oppfører seg som om de skulle føle smerte, men at de faktisk gjør det."

ANZCCART News, Do fish feel pain? This issue contains the Facts Sheet on Pain, ANZCCART News Vol. 12 No. 4, 1-3, December 1999: 
"The appropriate question appears not to be do fish feel pain? but rather, what types of pain do fish experience?"

Oidtmann, B., Pain and suffering in fish, Instut fur Zoologie, Fischereibiologie und Fischkrankheiten, Tierarztlichen Fakultat, Ludwig-Maximilians -Universitat Munchen,  Tierarztl Wochenschr 114, (7-8):277-82, Jul-Aug 2001:
"In the article presented, the information available in the literature to date is summarised. Based on this knowledge, the conclusion is drawn that fish are capable of feeling pain and that they are able to suffer in the sense of the word as used in the German animal welfare law."

Broom, D., Pain and adrenal function in fish, short oral in session Fish, II. Proceedings of the 36 th International Congress of the ISAE, Wageningen, the Netherlands, 2002:
"The general conclusion is that the functioning of the important coping systems which involve responses to actual or potential tissue damage, as well as the emergency physiological responses which facilitate flight, defence, or freezing, are generally similar in fish and mammals. Hence welfare assessment in fish should include measurement of the functioning of the pain and adrenal systems."

Chandroo, K., Moccia, R., Duncan, I., The welfare status of farmed fish: sentience and pain perception, long oral in session Fish I,  Proceedings of the 36th International Congress of the ISAE Congress, Wageningen, the Netherlands, 2002:
"In this review, we present new neurophysiological data and evaluate the anatomical, physiological, and behavioural evidence for the existence of sentience in fish, and in particular their ability to perceive pain."

Sneddon, L., Pain perception in the rainbow trout, short oral, session Fish II, Proceedings of the 36 th International Congress of the ISAE, Wageningen, the Netherlands, 2002:
"Since there were adverse behavioural and physiological responses to noxious stimulation and these chemicals are painful in higher vertebrates, it is likely that the rainbow trout is capable of pain reception."

Axén, C., Smärtlindring i samband med vaccination av fisk, Dept. of Animal Physiology, SLU. Sveriges lantbruksuniversitet, Veterinärmedicinska fakulteten, Veterinärprogrammet vol. 1, 2003:
"Det finns anledning att tro at vaccinering av fisk orsakar smärta. Målet med denna studie var att se om vi kunde minska fiskens lidande efter vaccination."

New Scientist, In brief, 6 September 2003:
"Trout treated with morphine have added to the evidence that fish feel pain."

Schiermeier, Q., New evidence that fish can feel pain, Trout study may fuel anti-angling pain debate, Nature News Service, Macmillan Magazines Ltd, 1-2, May  2003:
"New research hints that rainbow trout may feel pain when impaled on anglers´ hooks."

Sneddon, L. U., Braithwaite, V. A. and Gentle, M. J., Do fishes have nociceptors? Evidence for the evolution of a vertebrate sensory system, Proceedings of the Royal Society B: Biological Sciences, 270(1520), 1115–1121, 2003:
"This study provides significant evidence of nociception in teleost fishes and furthermore demonstrates that behaviour and physiology are affected over a prolonged period of time, suggesting discomfort."

Sneddon, L., Trigeminal somatosensory innervation of the head of a teleost fish with particular reference to nociception, Brain Research Bulletin, 972, 44-52, 2003:
"No major differences were found when making comparisons within receptor type and between receptor types. The fish nociceptors had similar pysiological properties to nociceptors found in higher vertebrates."  [...] Discussion, s. 51: " The fish nociceptors share common elements with mammalian nociceptors and, therefore, these properties are possibly fundamental aspects of structure and function of nociceptive neurons."

Sneddon, L. U., The evidence for pain in fish: the use of morphine as an analgesic, Applied Animal Behaviour Science, 83(2), 153-162, 2003:
"It is concluded that these pain-related behaviours are not simple reflexes and therefore there is the potential for pain perception in fish." [...] "Therefore, it is likely that fish are capable of pain perception and this study has shown that the criteria for animal pain have been fulfilled (Zimmerman, 1986) hence it appears that fish can perceive pain."

Chandroo, K., Duncan, I. and Moccia, R., Can fish suffer?: perspectives on sentience, pain, fear and stress, Applied Animal Behaviour Science, 86(3-4), 225–250, 2004:
"Anatomical, pharmacological and behavioural data suggest that affective states of pain, fear and stress are likely to be experienced by fish in similar ways as in tetrapods."

Jensen, P., Fisk oppfatter smerte, Aqua Vision, Norsk fiskeoppdrett Fiskeriteknisk fagblad, 2004:
"Vår litteraturgjennomgang har vist at smerte, frykt og ubehag sannsynligvis oppleves av fisk."

Sohlberg, S., Mejdell, C., Ranheim, B., Søli, N., Oppfatter fisk smerte, frykt og ubehag? En litteraturgjennomgang. Norsk Veterinærtidsskrift 116(6), 429-435, 2004:
"... fisk har anatomiske, neurofysiologiske og biokjemiske forutsetninger for å føle smerte. I tillegg viser fisk atferd som er karakteristisk for en smertereaksjon på potensielt smertefulle stimuli." [...] "Denne litteraturgjennomgangen har vist at smerte, frykt og ubehag sannsynligvis oppleves av fisk. [...] Det ville være en uetterrettelig påstand å hevde at fisk opplever smerte på akkurat samme måte som et menneske eller et annet pattedyr, men vi bør i det minste, etter vår mening, kunne akseptere at "fiskesmerte" kan være like viktig for fisken som "menneskesmerte" er for mennesker."

Rodríguez, F., Durán, E., Gómez, A., Ocana, F.M., Álvarez, E., Jiménez-Moya, F., Broglio, C., Salas, C., Cognitive and emotional functions of the teleost fish cerebellum, Brain Research Bulletin 66, 365-370, 2005:
"These data indicate that the functional involvement of the teleost cerebellum in learning and memory is strikingly similar to mammals and suggest that the cognitive and emotional functions of the cerebellum may have evolved early in vertebrate evolution, having been conserved along the phylogenetic history of the extant vertebrate groups."

Braithwaite, V. A. and Boulcott, P., Pain perception, aversion and fear in fish, Diseases of aquatic organisms, 75, 131–138, 2007:
"Teleosts possess specialised cutaneous pain receptors that are sensitive to damaging stimuli such as excessive heat and noxious chemicals and to mechanical pressure. The presence of a nociceptive system is clearly a necessary component for the perception of pain, but alone it does not provide evidence that the fish have an awareness of stimuli we would consider to be painful in ourselves or other terrestrial vertebrates such as birds and mammals. However, the fact that changes in the normal behavioural repertoire of the fish studied occurred after the administration of a noxious event does allow us to infer that the fish attended to this noxious stimulus in a way that was not just merely responsive."

Nordgreen, J., Horsberg, T., Ranheim, B., Chen, A., Somatosensory evoked potentials in the telecephalon of Atlantic salmon (Salmo salar) following galvanic stimulation of the tail, Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, (1-16), Forsøksdyrutvalgets møte 20 Mars 2007:
"Even though our results give no information about how fish perceive what humans would perceive as painful stimuli, they add to an increasing body of studies indicating that fish have all the prerequisites for complex processing of external events."

Ashley P., Sneddon, L., Pain and Fear in Fish, Part I, Chapter 4, 49-77, in: Fish Welfare, ed. Branson, E., Blackwell Publishing, Oxford, UK, 2008:
"Empirical evidence from studies designed to examine pain and fear in fish has also produced significant evidence for the ability of fish to experience these two forms of suffering." [...] s. 61: "In summary, fish, ... do appear to fulfil the criteria for nociception and there is the real potential for pain perception." s. 67: "If we accept that fish are capable of experiencing some form of pain and fear then we have to accept that their well-being is impaired when we subject them to any tissue damaging or fear-causing event."

Braithwaite, V., Boulcott, P., Can Fish Suffer?, Part I, Chapter 5, 78 - 92, in: Fish Welfare, ed. Branson, E., Blackwell Publishing, Oxford, UK, 2008:
"In summary, the continuing body of work on fish pain and suffering has produced a picture of an animal which is capable of responding physiologically to pain, and whose normal suite of behavioural repertoires alters in response to aversive stimuli, sometimes over long periods of time."

Nordgreen J., Nociception and pain in teleost fish, Thesis for the degree of PhD, Norges veterinærhøgskole, Oslo, 2009:
"Det finnes ingen gullstandard for smertefølelse. Imidlertid tyder funnene som presenteres i denne avhandlingen, sammen med det vi kjenner om fiskens nervesystem og adferd fra før, på at fisk ikke bare har nosisepsjon, men også bevisst smertefølelse."

Nordgreen, J., Garner, J.P., Janczak, J.P., Ranheim, B., Muir, W.M., and Horsberg, T.E., Thermonociception in fish: Effects of two different doses of morphine on thermal threshold and post-test behaviour in goldfish (Carassius auratus), Applied Animal Behaviour Science vol. 119, nr. 1-2, juni, 2009:
"All 16 fish responded to the heat with an escape response, with a mean baseline of 38 degrees C. However, morphine at 40 and 50 mg kg 1 could not be demonstrated to have a biologically relevant analgesic effect, but did significantly decrease the impact of heat stimulation on behaviour in the home tank." [...] "Both as production and laboratory animals, fish are subjected to noxious, potentially painful treatments such as blood sampling, fin tagging, toxicology testing and different surgical procedures. Our knowledge of fish physiology and the efficacy of different analgesics does not match the severity of the procedures to which fish are exposed and there is a need for research aimed at developing good analgesic protocols for fish."

Posner L.P., Pain and distress in fish: a review of the evidence, ILAR Journal vol 50 nr 4, 2009:
"The fact that ILAR Journal has chosen to dedicate an entire issue to Pain and Distress in Fish suggests growing acceptance in the scientific community that fish neuroanatomy and behavioral responses reveal that these animals feel pain."

Sneddon, L. U., Pain Perception in Fish: Indicators and Endpoints, ILAR Journal 50(4), 338-342, 2009:
"It is clear from the research evidence that fish are capable of nociception and that their experience meets the criteria for animal pain and is biologically important to the individual."

Brown, C., Fish intelligence, sentience and ethics, Animal Cognition, 2014:
"A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates."

Sneddon, L. U., Pain in aquatic animals, 218, 967-976, 2015:
"Contemporary studies over the last 10 years have demonstrated that bony fish possess nociceptors that are similar to those in mammals; that they demonstrate pain-related changes in physiology and behaviour that are reduced by painkillers; that they exhibit higher brain activity when painfully stimulated; and that pain is more important than showing fear or anti-predator behaviour in bony fish."

Brown, C., Comparative evolutionary approach to pain perception in fishes, Animal Sentience, 2016:
"Rather than to suppose that pain spontaneously arose somewhere else in the vertebrate lineage (e.g., between amphibians and reptiles), it is more parsimonious to infer that fish feel pain for the same reasons the rest of the vertebrates do. (By the way, from a phylogenetic perspective, all tetrapods are bony fishes!) Thus the emphasis of scientific investigation should be on proving that fish do not feel pain and coming up with a plausible evolutionary explanation for this lack. Until that is proven beyond doubt, our null position should be that fish do feel pain."

Broom, D., Fish brains and behaviour indicate capacity for feeling pain, Animal Sentience, 2016:
"Almost all of the characteristics of the mammalian pain system are also described for fish. Emotions, feelings and learning from these are controlled in the fish brain in areas anatomically different but functionally very similar to those in mammals. The evidence of pain and fear system function in fish is so similar to that in humans and other mammals that it is logical to conclude that fish feel fear and pain. Fish are sentient beings."

Gonçalves-de-Freitas, E., Pain and fish welfare, Animal Sentience, 2016:
"[F]ish have receptors for opioids, which subserve the defensive phase of pain in mammals (the absence of pain after injury, allowing animals to fight or flee). Evolutionarily, it is more plausible and parsimonious to infer that such an adaptive defensive mechanism was ancient and was preserved throughout vertebrate evolution."

Walters, E. T., Pain-capable neural substrates may be widely available in the animal kingdom, Animal Sentience, 2016:
"The number of neurons intensely and coordinately activated during noxious stimulation may be relatively large even in simple brains. […] The logical possibility that coordinated activity of perhaps hundreds or thousands of neurons (rather than many millions) may produce an aversive awareness of noxious stimulation reinforces the opinion that fish, amphibians, reptiles, and some invertebrates may experience forms of conscious pain."

Dinets, V., No cortex, no cry, Animal Sentience, 2016:
"Many animals have specialized neural receptors called nociceptors; their only known function is generating signals of pain (see Fein 2012 for a referenced overview). Unless some other function is discovered, their presence must be considered an irrefutable proof that the animal can feel pain. Fish have them (Sneddon et al. 2003). Case closed."

Mather, J., An invertebrate perspective on pain, Animal Sentience, 2016:
"Although Key (2016) argues that mammals feel pain and fish do not, from an invertebrate perspective, it is obvious that the pain experience is shared by animals from a number of different animal groups."

Brown, C., Fish pain: An inconvenient truth, Animal Sentience, 2016:
"The broad consensus from the scientific community is that fish most likely feel pain and it is time governments display courage enough to act."

Safina, C., Fish pain's burden of proof, Animal Sentience, 2016:
"An actively feeding shark that has just voraciously eaten several chunks of fish bites a stinging jellyfish in apparent error and immediately shakes its head to eject the jellyfish. Jellyfish contain nutrients; why would the shark act as though feeling the pain of the stings? Indeed, would jellyfish sting predatory fish if fish cannot experience pain? Indeed, jellyfish and stingrays were stinging fish millions of years before mammals existed. The observation is anecdotal, but it is anecdotal evidence bearing directly on the question."

Safina, C., Fish pain: A painful topic, Animal Sentience, 2016:
"How much pain is a fish capable of feeling? Many fish seldom touch anything except their prey, and many prey have spines. I would not expect fish to have dense touch and pain receptors in their lips as we do. And it appears that pain receptors are relatively sparse around the head (Chervova and Lapshin 2004). But they do exist, so one must ask what an animal does with pain receptors."

Balcombe, J., Cognitive evidence of fish sentience, Animal Sentience, 2016:
"Lack of a cortex is flimsy grounds for denying pain to fish, for on that criterion we must also then deny it to all non-mammals, including birds, which goes against scientific consensus. Notwithstanding science’s fundamental inability to prove anything, the precautionary principal dictates that we should give the benefit of the doubt to fish, and the state of the oceans dictates that we act on it now."

Sneddon, L. U. and Leach, M. C., Anthropomorphic denial of fish pain, Animal Sentience, 2016:
"For fish we know there is electrophysiological activity during painful stimulation and that there exist differences in gene expression at the molecular level for the effects of noxious versus innocuous stimuli. Functional magnetic resonance imaging likewise reveals a profound change in forebrain activity in fish during painful stimulation (Reilly et al. 2008; Dunlop& Laming 2005; Nordgreen et al. 2007; Sneddon2011). Key states that this brain activity is not symptomatic of pain even though the same data would be accepted as such in rodent species that are routinely used as clinical models for human pain (Sneddon et al. 2014)."

Lopez-Luna, J., Al-Jubouri, Q., Al-Nuaimy, W. and Sneddon, L. U., Reduction in activity by noxious chemical stimulation is ameliorated by immersion in analgesic drugs in zebrafish, Journal of Experimental Biology 220, 1451-1458, 2017:
"Recent investigations have demonstrated that teleost fish have nociceptors, receptors that detect potentially painful stimuli, which are very similar to those found in mammals (Ashley et al., 2007; Roques et al., 2010; Sneddon, 2002). A variety of species also exhibit adverse behavioural and physiological responses to a potentially painful event (Dunlop and Laming, 2005; Reilly et al.,2008)."

Pouca, C. V. and Brown, C., Contemporary topics in fish cognition and behaviour, Behavioral Sciences, 16, 46–52, 2017:
"As Brown [3] highlights, notwithstanding the complexity of the debate and whether we have definitive answers, current knowledge on their cognitive sophistication and pain perception suggests that the best approach is to give them the same welfare protection as any other vertebrate."

Manzotti, R., The human nervous system is not the gold standard for pain, Animal Sentience 145, 2018:
"A fish or any other animal that exhibits pain-avoidance because it has the right phylogenetic/ontogenetic history is likely to have all that is required for pain. […] There is no evidence that an animal that shows pain-avoidance does not feel pain, no matter what neural structure is involved. The precautionary principle stands strong and should be enforced."

Demin, K. A., Lakstygal, A. M. and Kalueff, A. V., Time to (finally) acknowledge that fish have emotionality and pain, Animal Sentience 146, 2018:
"Recent studies suggest that fish, like mammals, appear to have sentience (Brown, 2015; Rey et al., 2015), including mounting evidence that fish feel pain, respond to it behaviourally, and have all the requisite pain mechanisms and pathways (Malafoglia, Bryant, Raffaeli, Giordano, & Bellipanni, 2013)."

Franks, B., Sebo, J. and Horowitz, A., Fish are smart and feel pain: What about joy?, Animal Sentience 156, 2018:
"The body of evidence as a whole provides strong reason to accept that fish have experiences that we can plausibly describe as pain: Fish pay to avoid potentially painful stimuli, forfeit good outcomes for the sake of avoiding such stimuli, and seek out analgesics after potentially painful procedures (Sneddon, 2015). These behaviors require active decision making and are thus easier to explain by accepting that fish can experience pain rather than assuming that they cannot."

Sneddon, L. U., Wolfenden, D. C. C., Leach, M. C., Valentim, A. M., Steenbergen, P. J., Bardine, N., Broom, D. N. and Brown, C. Ample evidence for fish sentience and pain, Animal Sentience 162, 2018:
"Not so long ago, surgeons were denying pain relief to human babies because they could not feel pain (Segner 2016). We now know this is not true. To state the obvious: if an animal looks like it’s in pain, assume it is until the contrary is empirically demonstrated."

Woodruff, Michael L., Pain in fish: Evidence from peripheral nociceptors to pallial processing, Animal Sentience 162, 2018:
"The neuroanatomy and neurophysiology of the fish nervous system from the peripheral nerves to the pallium is able to support the sentient appreciation of pain, […]. In sum, then, the complexity of neurophysiological activity from peripheral nerves to the pallium supports the argument by Sneddon et al. (2018) that fishes consciously experience pain."

Mayers-Manor, Julia E., If it looks like a duck: Fish fit the criteria for pain perception, Animal Sentience 162, 2018:
"If a fish looks like she is in pain and acts like she is in pain, likelihood is the fish is in pain."

Brown, C. and Dorey, C., Pain and Emotion in Fishes – Fish Welfare Implications for Fisheries and Aquaculture, Animal Studies Journal, 8(2):175-201, 2019:
"Fishes are intelligent, social creatures. The evolutionary function of pain is ancient and highly conserved across all vertebrates and likely some invertebrates, and the evidence for pain in fishes is as good as for mammals. Fishes have neurones for nociception and the necessary brain parts for ‘emotional’ responses to pain."

Sneddon L. U., Evolution of nociception and pain: evidence from fish models. Philosophical Transactions of the Royal Society B, 374(1785), 2019:
"When experiencing a painful stimulus, fish do not show appropriate fear or anti-predator responses, and this may be detrimental in the natural environment if predation risk is a factor. Changes in behaviour are prevented by drugs that provide effective analgesia, providing evidence that these changes are driven by nociception and pain mechanisms. Taken together, this combined evidence suggests a pain experience that dominates attention in fish, and thus it is vital that we seek to minimize and alleviate pain in fish when logistically possible."

Segner, H., Reiser, S., Ruane, N., Rösch, R., Steinhagen, D. and Vehanen, T., Welfare of fishes in aquaculture, FAO Fisheries and Aquaculture Circular No. 1189, Budapest, FAO, 2019:
"[…]there is growing evidence that fish are sentient organisms, possessing, for instance, the ability to perceive pain."

Porcher, I. F., Commentary on The Great Fish Pain Debate, Issues, 2020:
"It is well known that in mammals the neocortex took over some functions that had already developed in vertebrates. So the argument that the lack of a neocortex results in the inability to feel pain should have been discarded long ago."

Sneddon, L. U., Commentary on The Great Fish Pain Debate, Issues, 2020:
"Of course, laboratories across the world are now confirming the early scientific findings and providing convincing evidence for pain in fish."

LES OGSÅ: 2,2 millioner fisk brukes som forsøksdyr

Rådet for dyreetikk, Sportsfiske - "Fang og slipp", uttalelse avgitt april 1998
Det er liten tvil om at fisk opplever smerte og stress i forbindelse med fisking, uansett om den blir avlivet eller sluppet fri igjen.

St.meld. nr. 12 (2002-2003) Om dyrehold og dyrevelferd
"Selv om det skulle eksistere en liten tvil om fisk faktisk føler smerte på lignende måte som pattedyr, bør vi handle som om den gjør det. [...] De fleste forskere mener i dag at det er sannsynlig at også fisk kjenner smerte, selv om det foreligger en viss uenighet. [...] Forskning knyttet til fisk som et levende dyr, dens sanseapparat, evne til å føle frykt, frustrasjon, smerte og andre faktorer som er viktige i dyrevern¬sammenheng, har ikke vært prioritert. Det er i denne sammenheng viktig å være klar over at man i vår kulturkrets har hatt, og fortsatt har, en annen grunnholdning til fisk enn til høyerestående virvel¬dyr. Fisk er tilpasset et annet element, mangler mimikk og lyd, har et fremmed kroppsspråk og en atferd som ikke direkte vekker vår medfølelse. Det er i dag likevel økende enighet om at dyrevelferd er viktig og bør vektlegges ikke bare av hensyn til forbrukeren, men for fiskens egen skyld."

Mattilsynet, Matportalen http://matportalen.no/Saker/foler_fisk_smerte, 14. mai 2003
"Dyrevernlovens paragraf nummer 2 sier at "dyr ikke skal komme i fare for å lide i utrengsmål". Statens dyrehelsetilsyn har kommet frem til at: Siden det ikke er bevist at fisk ikke kan føle smerte eller føler smerte må vi legge til grunn at fisk kan lide og føle smerte på samme måte som varmblodige pattedyr. Vi bør derfor ta like mye hensyn til fisken som det hensynet vi viser andre dyr når vi skal slakte dem. Dersom fisk føler smerte bør derfor denne følelsen vare så kort tid som mulig, og avlivingsmetoder bør derfor være hurtige."

Mattilsynet, Vannkvalitet og dyrevelferd, Rapport, 2004
"Mange naturvitenskapige forskere hevder at fisk sannsynligvis opplever smerte, frykt og stress på samme måte som andre virveldyr. Påstanden er basert på likhetspunkter mellom fisk og pattedyr når det gjelder anatomi, fysiologi og adferd. Det finnes pr. i dag godt naturvitenskapelig belegg for å hevde at fisk kan føle fiskesmerte. Forskningsresultater som beviser dette er beskrevet i en nylig publisert oversiktsartikkel om emnet (Sohlberg, 2004)."

Forskningsbehov innen dyrevelferd i Norge, Norges forskningsråd, februar 2005
"Selv om fisk er inkludert i dyrevernloven, har vi tradisjonelt behandlet fisk mindre skånsomt og med mindre empati enn andre husdyr. De siste årene har vi imidlertid fått et økt nasjonalt og internasjonalt fokus på fiskevelferd både fra forbrukere, dyrevernere, forvaltning, forskning og næring, og det er vitenskapelige indikasjoner på at fisk kan oppleve smerte og ubehag i langt større grad enn tidligere antatt. [...] Selv om det ikke er fullt ut klarlagt hvorvidt og hvordan fisk opplever smerte, er det med bakgrunn i nåværende dokumentasjon grunn til å forvente at fisk har evnen til å kunne oppleve ulike sykdomstilstander som ubehagelige. [...] Oppdrettsfisk har nevroanatomiske, atferdsmessige og fysiologiske egenskaper som er karakteristisk for bevisste kognitive prosesser. [...] Litteraturen gir oss dokumentasjon som tilsier at det er grunn til å tro at de fleste oppdrettsfisk har kognitive evner. [...] Det eksisterer nok dokumentasjon på fisk til å kunne fastslå at fisk er i stand til å respondere på smerteinduserende stimuli på en adaptiv måte på lik linje med husdyr. [...] Fisk blir i økende grad behandlet på lik linje med andre vertebrater når det gjelder dyrevelferdspørsmål, og i Norge er fiskevelferd blitt et prioritert områd innenfor næringsorganisajonr og forskningsinstitutter som arbeider innenfor fiskeri- og havbruksnæringen.

Nyere forskning viser at fisk er rikt utstyrt med smertereseptorer og nerveforbindelser til hjernen og viser langvarige atferdsmessige tegn på lidelse når de utsettes for antatt smertefulle påvirkninger. [...] Også en nyere norsk litteraturstudie (Sohlberg et al., 2004) og den engelske utredningen om fiskevelferd (FSBI2002), konkluderer med at fisk sannsynligvis er i stand til å lide. De refererer til undersøkelser som viser at fisk har neurofysiologiske, neuroanatomiske og biokjemiske forutsetninger for en formidling av potensielt smertefulle stimuli slik vi kjenner det fra pattedyr. Vitenskapskommiteen i EU og Norge holder det sannsynlig at fisk kan kjenne smerte og at fisk kan lide."

Vitenskapskomiteen for mat og miljø (VKM), Bedøving og avliving av store mengder oppdrettsfisk utenfor slakteri, 25. april 2005
Mange naturvitere hevder at fisk sannsynligvis opplever ubehag, smerte, frykt og stress på samme måte som andre virveldyr. Påstanden er basert på likhetspunkter mellom fisk og pattedyr når det gjelder anatomi, fysiologi og adferd. Det finnes i dag et godt naturvitenskapelig belegg for å hevde at fisk opplever fiskesmerte. [...] I debatten omkring fisk og dens evne til å oppleve smerte konkluderes det i dag med at fisk har både anatomiske, neurofysiologiske, biokjemiske og adferdsmessige forutsetninger for å ha et nosiseptivt system slik vi kjenner det fra pattedyr.

Havforskningsinstituttet, Dyrevelferdsmessige konsekvenser av vaksinasjon av fisk – effekter og bivirkninger, Rapport, 2006
"Nyere forskning viser at fisk er rikt utstyrt med smertereseptorer og nerveforbindelser til hjernen og viser langvarige atferdsmessige tegn på lidelse når de utsettes for antatt smertefulle påvirkninger (Sneddon et al. 2003). Chandroo et al. (2004 a, b) fokuserer på om fisk har en bevissthet vedrørende egne lidelser og refererer til flere forsøk som indikerer at ulike fiskearter har såkalt ”deklarativ representasjon” karakteristisk for bevissthet samt nevroanatomiske, farmakologiske og atferdsmessige undersøkelser som kan tyde på at fisk opplever affektive tilstander og konkluderer med at fisk har evnen til å lide. Også en nyere norsk litteraturstudie (Sohlberg et al. 2004) og den engelske utredningen om fiskevelferd (FSBI 2002), konkluderer med at fisk sannsynligvis er i stand til å lide."

Landbruks- og matdepartementet, forarbeidene til ny dyrevelferdslov, 16. november 2007
"Ved behandling av dyrevelferdsmeldingen pekte Stortingets næringskomité i Innst.S. nr. 226 (2002-2003) på at det i Norge ikke er tradisjon for å behandle fisk som sansende dyr. Departementene understreker at oppdrettsfisk likevel har krav på godt stell og levemiljø på linje med landlevende dyr. Det har de siste årene blitt mye større oppmerksomhet omkring velferd hos oppdrettsfisk. Også innenfor EU får velferd hos fisk mer og mer oppmerksomhet. European Food Safety Authority (EFSA) konkluderer i sin vitenskapelige rapport vedrørende bedøving og slakting av dyr (www.efsa.europa.eu/en/science/ahaw/ahaw_opinions/495.html) med at det er tilstrekkelig dokumentasjon som tyder på at fisk oppfatter frykt og smerte, til at dette bør legges til grunn for velferdsbetraktninger."

Den europeiske myndighet for næringsmiddeltrygghet (EFSA), Animal consciousness. EFSA supporting publication, 2017
"It is clear to us that case studies and single published paper on a given phenomenon are not sufficient to conclude on whether animals, and more particularly livestock animals, can have conscious experience of their environment, self or conspecifics. However, the overall picture obtained from the large range of species considered strongly provides evidence for different types of consciousness in both livestock and fish."

Undersøkelse for Europaparlamentets fiskerikomité, Dyrevelferd for oppdrettsfisk, juni 2023
"Scientific data indicate that fish can experience pain and possess a sophisticated and effective sensory system and cognitive abilities, making them capable of adapting to an incredible array of habitats."

Les mer fakta om fiskeoppdrett her.