What fish feel

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Animal Welfare Institute Quarterly

http://www.awionline.org/pubs/Quarterly/05_54_04/05_54_4p19.htm

 

What Fish Feel

Researcher Stephanie Yue of the University of Guelph in Canada shares

her team's surprising findings on fish sentience and ponders the

ethical implications.

 

It is not uncommon to find a variety of whole fish displayed on ice

at any average grocery store. Yet practically every other type of

meat is cut into portions and wrapped in clean packages that bear no

physical semblance to the animal from whom they came. While most

people in our Western culture would find it disturbing to see whole

cows and pigs on sale for meat, most have no problem with the sight

of a large salmon laid out in a similar manner.

 

Our emotional distance from fish may stem from the general feeling

that they fall below the phylogenetic line where sentience begins.

This may be because our present knowledge of assessing suffering in

fish is inadequate-in part because fish do not typically display

traditional and obvious signs we are familiar with in other animals.

They are not capable of facial expression, nor can most species of

fish vocalize; given their general anatomical structure, changes in

body posture are extremely limited. Consequently, their use in

scientific experimentation, in place of birds and mammals, is seen as

ethically acceptable.

 

Overcoming Taboo

 

It's not surprising then to see that, according to statistics

provided by the Canadian Council on Animal Care, there is a rising

trend in the use of fish in research. In Canada, there was a 463

percent increase between 1975 and 2002, resulting in over 600,000

fish used for scientific research in 2002. Fish consumption has also

risen steadily, mostly due to increased interest in a healthy

alternative to traditional protein sources such as beef, chicken and

pork. Huge numbers of fish are used by humans on a regular basis.

 

However, recent anatomical, physiological, neuropharmacological and

behavioral studies suggest fish can suffer in ways similar to

" higher " vertebrate animals. Considering the large numbers of fish we

use, these findings should be enough of a reason for us to consider

their welfare as a serious matter. In addition, animal welfare should

be defined by how an animal " feels " -not just by how well it

physically copes with environmental conditions such as absence of

disease, lack of injury and good growth. Since sentient creatures

have the capacity to subjectively and consciously experience things,

it makes sense to investigate the fish's capacity to suffer.

 

This is the project our fish welfare group at the University of

Guelph is currently undertaking. It is not a trivial endeavor, for

whether fish even possess the neuroanatomical structures that

generate the phenomenon of consciousness is still a subject up for

debate. The topic of consciousness has had a tumultuous history

itself, and it has been less than a couple decades since words like

" consciousness " and " sentience " have reappeared in scientific animal

literature. We are only slowly overcoming the taboo of studying

conscious thought processes and voluntary behavior.

 

From our studies on highly domesticated rainbow trout, we have seen

these fish show behavior that is much more flexible and complex than

was previously acknowledged. We have found that trout have some

cognitive capacity that rivals that of mammalian laboratory animals,

like rats. They not only show the ability to learn, but they also

have memory of the things they learned-so they can anticipate events

and adjust their behavior accordingly. This means some of their

behavioral repertoire is " purposeful " and lends evidence toward

" conscious " behavior.

 

Analyzing Fear

 

Most of our experiments delve into the phenomenon of fear. We try to

tease apart which responses to negative stimuli (in our case, an

oncoming dip net) are likely to be reflexive and which are

deliberate. These experiments often require fish to be trained in

tasks ranging from simply swimming away from an area where an

aversive stimulus resides, to highly artificial and relatively

sophisticated tasks such as pressing a lever in order to obtain a

reward.

 

We found that trout follow similar behavioral patterns when

frightened, as do other animals like mice. Mice show avoidance,

fleeing, freezing, and scanning of their environment and general

decrease in activity followed by gradual resumption of normal

behavior. Mice are deemed sentient animals with the capacity for a

range of subjective experiences. Why then should these same

behavioral patterns, when seen under similar experimental paradigms,

not be employed as evidence toward the possibility of subjective

experiences in fish?

 

There is more evidence that fish do have some level of consciousness

than there is evidence against it, and it is logically more likely

that fish are sentient animals than they are not. What level of

consciousness they possess, however, remains to be determined. We

still have much to learn before we can properly generate guidelines

specifically tailored to the needs of different species of fish kept

in captivity. Yet we are moving in the right direction by

entertaining the notion that fish may indeed be worthy of more moral

consideration than they have had in the past.

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This research project was made possible through a grant from Animal

Welfare Institute and the Center for Alternatives to Animal Testing.

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Not unlike a rat who will press a lever for a food pellet, the trout

in this photograph presses a pendulum for a food reward during a

recent investigation of fear responses in rainbow trout.

 

A case of classical conditioning-cued by a blue light signal, a trout

swims through a door into an adjacent chamber in order to avoid an

oncoming plunging dip net. photos: Stephanie Yue

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