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Brazil survey: Animal welfare perspectives vary between producers, researchers

Carlos Eduardo M. Viegas da Silva Rubens Nunes Ana Beatriz Santos de Oliveira Elisabete Maria Macedo Viegas

Humane slaughter is correlated with animal welfare, in that its goal is to reduce or eliminate distress and suffering

animal welfare
Most respondents said that animal welfare involves elements beyond “distress.”

The concept of “animal welfare” is built by diverse players in the fish-farming production chain who are intertwined in an extensive network of actions, ideas, devices, laws, people and animals. There is no unambiguous definition of animal welfare.

The social perception of welfare or suffering of a certain animal species cannot be easily separated from a supposed “empirical” animal welfare. The authors performed a study to identify how different groups (producers and researchers) within the production chain of Brazilian aquaculture described and evaluated the concept of animal welfare applied to fish production.

Study setup

The study used a questionnaire to determine how the animal welfare concept and, in particular, how fish slaughtering methods were understood by different players involved in fish production. The questionnaire was administered to participants at the July 2013 VI Health Course in Fish Farming held at the Aquaculture Center of the University of São Paulo in Jaboticabal, São Paulo, Brazil.

A total of 83 completed questionnaires were received. Participants were classified by occupation into two groups: producers and researchers. Composed of fish farmers, fingerling breeders, processors and suppliers, the producers group was more heterogeneous. The group of researchers was more homogeneous, consisting primarily of graduate students.

Results and discussion

The survey results are summarized in several tables below. Table 1 summarizes the occupation distribution of the participants. The survey sought to determine the level of knowledge the respondents had about animal welfare in sectors other than fish farming. Table 2 shows the responses obtained.

Eduardo, Participants’ main occupations, Table 1

Aquaculture SectorNumberPercentage
Commercial production3238.6
Production supplies2530.1
Table 1. Participants’ main occupations in relation to fish farming.

Eduardo, Knowledge about animal welfare, Table 2

Knowledge LevelNumberPercentage
Table 2. Knowledge about animal welfare.

Since fish do not express reactions to pain or distress in the same manner as terrestrial mammals, which mainly emit sounds, interviewees were asked if fish are capable of feeling pain. Responses are recorded in Table 3.

Eduardo, Opinions about fish sensitivity, Table 3

No response22.4
Table 3. Opinions about fish sensitivity.

Table 4 summarizes opinions on the slaughter methods used in fish farming. Table 5 shows the opinions expressed regarding why animal welfare practices should be applied in fish farming.

Eduardo, Perceptions about slaughter methods, Table 4

Slaughter MethodVery Cruel
Very Cruel
Less Cruel
Less Cruel
Thermal shock11.267.24655.4
Percussive stunning2226.51720.51012.0
Electrical stunning135.71113.31315.7
Removal from water2833.71821.711.2
No response910.8910.8910.8
Table 4. Perceptions about slaughter methods.

Question: How do you perceive slaughter methods based on the level of cruelty to the fish?

Eduardo, Reasons to apply animal welfare, Table 5

ReasonMore Important
More Important
Less Important
Less Important
To benefit final consumers67.2910.81521.4
Meat quality2226.52732.556.0
Fish mortality1720.51315.756.0
Animal rights1922.9910.822.4
Laws prohibit mistreatment22.444.82530.1
No response89.61113.31315.7
Table 5. Reasons to apply animal welfare concepts in fish farming.

Question: Why should animal welfare be applied in fish farming?

Some convergence was noted between the producers’ and researchers’ responses on the following points:

• The least important reason to adopt animal welfare practices in fish farming is the animal mistreatment prohibition law.
• Fish are capable of feeling pain, cold, fear and hunger.
• Animal welfare involves elements beyond “distress.” But the percentage of producers that identified well-being as absence of distress (19.4 percent) was higher than the respective percentage of researchers, 4.2 percent, who identified distress in that manner.
• The least cruel slaughter method is thermal shock: placing fish in a mixture of water and ice.

Survey participants indicated that, in general, Brazil’s fish farming industry is applying animal welfare principles to some degree (Table 6). However, there were significant differences of opinion between producers and researchers on several important aspects of humane slaughter and animal welfare.

Eduardo, Overall perceptions, Table 6

Element of Welfare NumberPercentage
Hunger, thirst, malnutritionIs not being applied1113.3
Hunger, thirst, malnutritionIs being applied but can improve3643.4
Hunger, thirst, malnutritionIs being applied2833.7
Hunger, thirst, malnutritionDid not respond89.6
Pain, injury, diseaseIs not being applied1113.3
Pain, injury, diseaseIs being applied but can improve5465.1
Pain, injury, diseaseIs being applied910.8
Pain, injury, diseaseDid not respond7489.2
DiscomfortIs not being applied2833.7
DiscomfortIs being applied but can improve4756.6
DiscomfortIs being applied00
DiscomfortDid not respond89.6
Expression of normal behaviorIs not being applied3643.4
Expression of normal behaviorIs being applied but can improve3441.0
Expression of normal behaviorIs being applied33.6
Expression of normal behaviorDid not respond1012.0
Fear and distressIs not being applied3238.6
Fear and distressIs being applied but can improve3947.0
Fear and distressIs being applied11.2
Fear and distressDid not respond1113.3
Table 6. Overall perceptions regarding the main elements of fish welfare.

The two groups’ responses regarding the minimum time required to carry out fish filleting after the initiation of thermal shock diverged. Researchers recommended 19 minutes, on average, and producers supported 13 minutes.

Regarding the freedom from discomfort, producers assess the current situation of Brazilian fish farms less unfavorably than researchers do.

In evaluating the slaughter method that consists of bleeding fish by cutting the gills, 9 percent of the researchers classified it as very cruel, while 21 percent of the producers found it a cruel slaughter method. About 28 percent of producers and only 8 percent of the researchers considered subjecting fish to an electrical discharge for slaughter very cruel.

When asked the main reason animal welfare is important in fish farming, 36.7 percent of producers said the quality of meat obtained is better when animals are treated well. For researchers, the main reason was that animals have the right not to suffer (42.9 percent).


There were some agreements and disagreements between the two groups of respondents regarding fish welfare. However, even when there was general agreement about certain aspects of the animal welfare concept, some internal differences regarding their level of importance persisted within each group.

This was likely a case of relating “animal distress” with “animal welfare,” and can not be explained on the basis of significantly different technical knowledge between the groups’ members.

It seems more plausible to assume that the different ideas on what fish welfare is or the most humane slaughtering method could be explained by the introduction of the sociological concept of “representation,” in which “animal welfare” is, among other things, a symbolic linguistic construction that involves a variety of players.

Humane slaughter is correlated with animal welfare, in that its goal is to reduce or eliminate distress and suffering. For fish, in particular, this correlation is mediated by the representations that people involved in fish-farming activities make for themselves about these animals’ sensitivity to suffering.

(Editor’s Note: This article was originally published in the March/April 2014 print edition of the Global Aquaculture Advocate.)