improving welfare for aquarium fish

222 Pages·2014·9.88 MB·English

by  Miriam Sullivan

FISHING
 FOR
 ANSWERS:

Improving
 welfare
 for
 aquarium
 fish

Miriam
 Elizabeth
 Sullivan

BSc
 (Hons),
 DipSciComm

This
 thesis
 is
 presented
 for
 the
 degree
 of
 Doctor
 of
 Philosophy

at

The
 University
 of
 Western
 Australia

Science
 Communication
 Program

School
 of
 Animal
 Biology

Perth,
 Australia

JULY
 2014
ii
Abstract

More than 1.5 billion fish are traded internationally each year. Fish are the most
numerous type of pet and are kept in approximately 10% of Western households.
Several studies indicate that most people do not consider fish welfare to be important,
although scientific evidence shows that fish are behaviourally complex and feel pain.
The aim of this thesis is to develop pathways for improving the welfare of pet fish.
The welfare of captive fish is influenced by factors contributing to fish health (such as
water quality, stress and behavioural needs) as well as factors contributing to the
owner’s provision of care (such as knowledge, attitudes, social norms and media
coverage). The relationships between these factors were explored using three
methods: a survey of fish owners; an intervention using a short film to improve owner
attitudes and behaviour; and the development of preference and motivational testing
for determining the value of enrichment for fish.
The survey identified fish owners’ perceptions of the main welfare issues affecting
pet fish and helped model the attitudes that underlie aquarist behaviour. Fish owners
responding to the survey (n = 534) reported that disease and old age were the most
common causes of death for their pet fish, although it is likely that many of them
underestimated the role of water quality in fish health. The majority of respondents
(73%) reported that they are knowledgeable about fish care and actively share and
seek information about their fish. However, more than a quarter of respondents (27%)
admitted that they had limited knowledge of fish care and rarely sought information
or social support for their hobby. Almost all respondents provided structural
enrichment such as gravel and shelters for their fish, but less knowledgeable owners
were more likely to provide artificial plants than real ones.
Providing fish owners (n = 195) with a short film encouraging them to clean their
aquaria weekly did increase the frequency of tank cleaning, but only if they already
intended to do so. There was no measurable change in attitudes after watching the
film, but using a positively framed film appeared to increase recall of the key message
compared to the negatively framed film.
iii
Preference and motivational tests were found to be useful methods for studying the
value of environmental enrichment for fish. Goldfish were found to spend an equal
amount of time and effort to access both real and artificial plants. This suggests that
keeping artificial plants rather than real plants does not, in itself, influence welfare
compared to real plants. However, participants in the film intervention showed an
association between owning artificial plants and cleaning out the tank less frequently,
which could exacerbate water quality issues.
These results emphasise that fish owners are not a homogenous group. Most aquarists
who responded to the survey are dedicated to their hobby and aim to maximize fish
welfare, but they are limited by a shortage of scientific research on ornamental fish
species. Less committed fish owners are hard to reach through traditional
communication channels, but targeted attempts should be made to improve their
engagement with animal welfare. Further research should focus on the influence of
message framing on behavioural change and on clarifying the value of enrichment for
fish health.

iv
Contents

Abstract
 .......................................................................................................................................................
 iii

List
 of
 Figures
 ..........................................................................................................................................
 vii

List
 of
 Tables
 .............................................................................................................................................
 ix

List
 of
 Appendices
 ...................................................................................................................................
 x

Declaration
 of
 Authorship
 and
 Publications
 Arising
 ...............................................................
 xi

1
  School of Thought: Literature Review .................................................................... 1

1.1
  Introduction
 ..........................................................................................................................................
 1

Fish
 Characteristics
 ................................................................................................................................
 2

1.2
  The
 scale
 of
 the
 issue—
 how
 many
 pet
 fish
 are
 there?
 .........................................................
 2

1.3
  What
 is
 animal
 welfare
 and
 how
 is
 it
 protected?
 ....................................................................
 4

1.4
  Are
 fish
 worthy
 of
 protection?
 ....................................................................................................
 10

1.5
  Potential
 welfare
 issues
 for
 pet
 fish.
 .........................................................................................
 19

1.6
  The
 effect
 of
 enrichment
 on
 fish
 welfare
 ................................................................................
 29

1.7
  Measuring
 fish
 welfare
 ...................................................................................................................
 32

Human
 Characteristics
 .......................................................................................................................
 35

1.8
  Why
 do
 people
 keep
 pets?
 ...........................................................................................................
 35

1.9
  Why
 do
 people
 keep
 fish?
 .............................................................................................................
 39

1.10
  What
 influences
 pet
 owner
 behaviour?
 ................................................................................
 45

1.11
  Influence
 of
 the
 media
 on
 behaviour
 .....................................................................................
 52

1.12
  Framing
 animal
 welfare
 ...............................................................................................................
 58

1.13
  Summary
 and
 Research
 Questions
 ..........................................................................................
 61

2
  Casting a wide net: What are the main welfare problems identified by fish
owners? .......................................................................................................................... 65

2.1
  Introduction
 .......................................................................................................................................
 65

2.2
  Materials
 and
 Methods
 ..................................................................................................................
 68

2.3
  Results
 ..................................................................................................................................................
 71

2.4
  Discussion
 ...........................................................................................................................................
 75

2.5
  Conclusion
 ..........................................................................................................................................
 79

3
  Are you gill-ty of pet neglect: What owner attributes are associated with
knowledgeable care of pet fish? ................................................................................... 81

v
3.1
  Introduction
 .......................................................................................................................................
 81

3.2
  Methods
 ..............................................................................................................................................
 82

3.3
  Results
 ..................................................................................................................................................
 85

3.4
  Discussion
 ...........................................................................................................................................
 88

3.5
  Conclusion
 ..........................................................................................................................................
 92

4
  Reeling them in: Can short films improve knowledge, attitudes and
behaviour towards pet fish care? ................................................................................. 93

4.1
  Background
 .........................................................................................................................................
 93

4.2
  Methods
 ..............................................................................................................................................
 95

4.3
  Results
 ..................................................................................................................................................
 99

4.4
  Discussion
 .........................................................................................................................................
 105

4.5
  Conclusion
 ........................................................................................................................................
 109

5
  Why did the fish cross the tank: How can we objectively measure the value of
enrichment for captive fish? ...................................................................................... 111

5.1
  Introduction
 .....................................................................................................................................
 111

5.2
  Methods
 ............................................................................................................................................
 113

5.3
  Results
 ................................................................................................................................................
 118

5.4
  Discussion
 .........................................................................................................................................
 121

5.5
  Conclusion
 ........................................................................................................................................
 124

6
  Fin-ishing Up: General Discussion & Recommendations ................................. 125

6.1
  Identification
 of
 current
 problems
 for
 pet
 fish
 welfare
 ....................................................
 125

6.2
  Different
 types
 of
 aquarists
 ........................................................................................................
 128

6.3
  Developing
 strategies
 to
 change
 fish
 owner
 behaviour
 ...................................................
 130

6.4
  Improved
 methods
 for
 critically
 analysing
 the
 value
 of
 enrichment
 for
 fish
 welfare

  131

6.5
  Recommendations
 and
 future
 research
 .................................................................................
 132

6.6
  Conclusion
 ........................................................................................................................................
 135

7
  Glossary ................................................................................................................. 137

8
  References .............................................................................................................. 141

9
  Appendices ............................................................................................................. 177

10
 Tanks A Lot: Acknowledgements ........................................................................ 205

vi
List
 of
 Figures

Figure 1.2. Differences between Australian states in the legislative protection of fish
welfare. .............................................................................................................................. 9

Figure 1.3. Diseases in fish arise through interactions between the animal, the
pathogen and the environment ........................................................................................ 21

Figure 1.4. The influence of increased cost on the use of resources by animals in
motivational tests. ........................................................................................................... 34

Figure 1.5. Model of the Theory of Planned Behaviour. ................................................ 47

Figure 1.6. A diagrammatic representation of the fish and human factors that can
influence fish welfare. ..................................................................................................... 63

Figure 1.7. Relationship between ornamental fish welfare and the research questions
addressed in this thesis. ................................................................................................... 64

Figure 2.1. Respondents’ knowledge of fish biology according to the number of
individual fish kept. ........................................................................................................ 74

Figure 2.2. Differences in knowledge of fish biology between respondents who keep
different types of fish. ..................................................................................................... 74

Figure 4.1. Screenshots from the two short films used in the experiment. ..................... 95

Figure 4.2. Change in the knowledge, attitudes and behaviour of fish owners a month
after they watched a short educational film (p > 0.05). .................................................. 99

Figure 4.3. Fish owners intentions to act vs. actual behaviour in the month after they
watched a short educational film. ................................................................................. 101

Figure 4.4. Change in tank cleaning behaviour amongst those participants who had
indicated that they intended to clean the tank more often (n = 47)............................... 102

Figure 4.5. Relationship between the type of plants kept in the tank and the number of
times that the tank was cleaned over a month. .............................................................. 104

Figure 4.6. The proportion of respondents who stated that their fish husbandry was
already good compared to the number of times respondents cleaned out their tank in
the month prior to the first survey. ................................................................................ 105

Figure 5.1. Real and artificial plants used in the preference and motivational tests. .... 114

Figure 5.2. Experimental design for preference tests, viewed from above. .................. 115

Figure 5.3. Set up for motivational tests, viewed from above. ..................................... 116

Figure 5.4. Experimental design control for cost tests, viewed from above. ................ 117

vii
Figure 5.5. Mean amount of time that goldfish spent near plants during a 40-minute
preference test. .............................................................................................................. 119

Figure 5.6. Inelastic demand for access to plants and empty space in goldfish (n=19).120

Figure 5.7. Tunnel used by fish for gaining access to an empty compartment. ............ 121

Figure 6.1. Original findings of the thesis in relation to the theoretical conception of
fish welfare. ................................................................................................................... 126

viii
List
 of
 Tables

Table 1.1. Number of pets owned in Australia, the UK and the US. ................................ 4

Table 1.2. Summary of research on complex behaviours displayed by fish. .................. 16

Table 1.3. Factors that influence fish welfare. ................................................................ 23

Table 1.4. Common misconceptions about the biology of pet birds and fish that may
lead to poor welfare outcomes. ....................................................................................... 43

Table 2.1. Differences in survey questions addressed to respondents (n=534) based on
history of fish ownership. ............................................................................................... 69

Table 2.2. Type of fish kept by respondents. .................................................................. 72

Table 2.3. Common causes of death reported for aquarium fish. ................................... 72

Table 3.1. Survey questions grouped by factors that may be relevant to participants’
knowledge of fish care. ................................................................................................... 83

Table 3.2. Sources utilised for obtaining pet fish. .......................................................... 86

Table 3.3. Informational sources used by respondents when they were planning to
purchase new fish. ........................................................................................................... 87

Table 3.4. Characteristics of the two groups of fish owners determined using a two-
step cluster analysis. ........................................................................................................ 88

Table 4.1. Question alignment between the pre- and post- surveys. .............................. 98

Table 4.2. Study demographics and tank variables. ...................................................... 100

Table 4.3. Messages that respondents remembered a month after watch the film. ...... 103

Table 5.1. Measures of motivation in experimental treatments as the water current
increased in strength. .................................................................................................... 120

Table 5.2. Measures of motivation compared between treatments. .............................. 120

ix
List
 of
 Appendices

Appendix A Scientific names of the fish species referred to in the thesis. ................... 178

Appendix B Notes on reading the survey materials ...................................................... 180

Appendix C Survey: Importance of knowledge, attitudes and point of sale on the
welfare of aquarium fish. .............................................................................................. 181

Appendix D Survey: Influence of short films on aquarist behaviour ........................... 189

Appendix E Developing monitoring guidelines for fish welfare .................................. 196

x