amphibian and reptile pet markets in the eu

53 Pages·2012·1.84 MB·English

AMPHIBIAN AND REPTILE
PET MARKETS IN THE EU:
AN INVESTIGATION AND
ASSESSMENT
Phillip C Arena Catrina Steedman Clifford Warwick
Murdoch University Emergent Disease Foundation Emergent Disease Foundation
Peel Campus Riverside House Riverside House
Education Drive River Lawn Road River Lawn Road
Mandurah Tonbridge Tonbridge
Western Australia 6210 Kent TN9 1EP Kent TN9 1EP
UK UK
Arena, Steedman and Warwick, 2012
AMPHIBIAN AND REPTILE PET MARKETS IN THE EU:
AN INVESTIGATION AND ASSESSMENT
CONTENTS
Page
SUMMARY 5
INTRODUCTION 6
General 6
Animal welfare 8
Human health 9
Invasive alien species
PROJECT REMIT 11
Animal welfare 11
Public health and safety 11
Invasive alien species 11
RELEVANT KEY LITERATURE 11
Brief overview of some key existing reports on wildlife markets 11
Scientific 11
Semi-scientific 11
Non-scientific/not-determined 12
PROTOCOL & METHODS 12
Animal welfare assessment 12
Monitoring of the thermal environment 12
Figure 1. Line of sight 13
Table 1. Behavioural signs of captivity-stress 13
Figure 2. Sample table giving recording method for signs of arousal and discomfort 13
and related keys
Human health and visitor behaviour assessments 14
Figure 3a. Initial mode of contact observation system 14
Figure 3b. Subsequent mode of contact observation system 14
Figure 4. Mode of contact recording system 14
Invasive alien species assessment 14
RESULTS 15
Animal welfare 15
Figure 5. Stress-related behaviours among amphibians and reptiles at European markets 15
Figure 6. Proportion of animals exhibiting determined stress-related versus 15
undetermined behaviours
Figure 7. Proportion of animals exhibiting specific stress-related behaviours 16
Monitoring of the thermal environment 16
Table 2. Thermal recordings at three exotic pet market events 16
2 Amphibian and reptile pet markets in the EU –An investigation and assessment
Arena, Steedman and Warwick, 2012
AMPHIBIAN AND REPTILE PET MARKETS IN THE EU:
AN INVESTIGATION AND ASSESSMENT
CONTENTS
Page
Public health and visitor behaviour 16
Table 3. The number of visitors to vendors at three European markets and the proportion 17
that engaged in direct and indirect contact with presumed contaminated sources
Figure 8. The proportion of visitors to vendors making subsequent modes of contact 17
Figure 9. The proportion of visitors to vendors at each market making subsequent modes 17
of contact
Figure 10. Public health and visitor behaviour at three European markets 17
Invasive alien species 18
Country of origin 18
Figure 11. Total number of non-European species of amphibian and reptile present at three 18
European markets
Figure 12. Number of recognised Invasive Alien Species of amphibian and reptile recorded at 18
three European markets
Figure (cid:0)(cid:0)13. Intuitive invasive risk of amphibian and reptile species present at three 18
European markets
Figure (cid:0)(cid:0)14. Intuitive invasive risk of amphibian and reptiles species by taxonomic group 19
DISCUSSION 19
Animal welfare 19
Thermal considerations 20
General issues 21
Public health and visitor behaviour 21
Invasive alien species 22
Tolerable thermal range and climate-facilitated distribution 23
Dietary plasticity-facilitated distribution 23
Artificial dietary habituation 24
Artificial trait development 24
Opportunity for invasion 25
Figure 15. European countries hosting reptile shows in 2011 26
Opportunities for incidental escapes at markets 26
META ISSUES 26
Wild-caught versus captive-bred animals on offer 26
Estimation of the numbers of animals at events 27
Commercial and non-commercial sellers 27
Proponents’, organisers’ and sellers’ awareness and assessment of stress and 27
welfare at markets
Amphibian and reptile pet markets in the EU –An investigation and assessment 3
Arena, Steedman and Warwick, 2012
AMPHIBIAN AND REPTILE PET MARKETS IN THE EU:
AN INVESTIGATION AND ASSESSMENT
CONTENTS
Page
The temporary nature of markets 28
Unusual species 28
Figure 16. Proportion of IUCN Red Listed species of Testudines offered for trade in 29
European markets
Figure 17. Classification of IUCN Red Listed species of Testudines offered for trade in 29
European markets
Additional considerations regarding invasive alien species 29
Genetic pollution 30
Introduction of novel and invasive pathogens 30
CONCLUSIONS 30
Animal welfare 30
Human health 31
Invasive alien species 31
FINAL WORD AND RECOMMENDATIONS 31
European Commission 32
COMMISSIONED WORK 33
DECLARATION OF INTEREST(S) 33
ACKNOWLEDGEMENTS 33
AUTHORS 33
Authors’ mini-biographies 33
REFERENCES 35
Appendix 1. Major amphibian - (A) and reptile - (R) borne zoonotic infections and infestations 39
Appendix 2. Minor amphibian - (A) and reptile - (R) borne zoonotic infections and infestations 40
Appendix 3. List of species observed on display 41
Appendix 4. 47
Table A. European Market amphibian species, country of origin and invasive potential risk 47
Table B. European Market turtle species, country of origin and invasive potential risk 48
Table C. European Market snake species, country of origin and invasive potential risk 50
Table D. European Market lizard species, country of origin and invasive potential risk 51
Table E. European Market crocodilian species, country of origin and invasive potential risk 52
4 Amphibian and reptile pet markets in the EU –An investigation and assessment
Arena, Steedman and Warwick, 2012
SUMMARY
Wildlife markets occur in several regions of the world that within a relatively brief period all public attendees
and take different forms. According to region, wildlife potentially may be subjected to some level of
markets offer animals for various reasons including contamination.
culinary, medicinal, and pet purposes. These events have
attracted interest and concern from both the scientific l Invasive alien species– there is little doubt that a wide
(including biological, veterinary and medical fields), and range of species found at exotic pet markets have the
animal welfare and species protection communities. For adaptive potential to become invasive across
this investigation and report we have focussed on numerous regions within the EU. Our assessment is
amphibians and reptiles at pet markets. that the continued occurrence of exotic pet markets
makes the regular introduction of invasive species
We conducted onsite inspections at three European almost assured.
events: Terraristika (Hamm, Germany), the IHS Show
(Doncaster, UK), and Expoterraria (Sabadell, Spain), and Accordingly, we recommend that the European
we also conducted a desktop study. Three primary Commission pursue a policy of prohibition on exotic pet
subject areas were identified for focussed study: animal markets within its boundaries, and this should cover all
welfare; public health and safety; and invasive alien biological classes of vertebrate animals. In addition,
species potential. authorities should compile a database of all known pet
markets and their historical venues and make this
Animal welfare was assessed using scientifically information available for enforcement authorities to
established non-invasive observation of behavioural ensure local compliance with all prohibitive measures.
signs of stress in amphibians and reptiles. Public health Existing EU regulations and initiatives are available to
and safety was assessed by analysing visitor behaviour at implement these recommendations.
stalls that sold animals. Invasive alien species potential
was assessed using historical invasives success data, Phillip C Arena BScHons (Reptile Ecology) PhD (Reptile
propagule-pressure theory, tolerable thermal range and Amphibian Anatomy and Physiology)
(climate matching), taxonomic relationship with known
invasives, popularity within the pet trade, reproductive Catrina Steedman BScHons (Psychology) AMSB (Reptile
potential, and thermal and dietary requirements. This Biology)
was supplemented with an additional assessment of
invasive risk which we called ‘intuitive-risk’ (IR). This mode Clifford WarwickDipMedSci (Medicine, Zoonoses) CBiol
of assessment is based on considering and balancing a (Reptile Biology) FSB (Reptile Biology)
variety of factors including those already mentioned plus
our interpretation of ‘species overall plasticity’. We also
considered several additional relevant subjects including:
wild-caught versus captive-bred animals on offer;
commercial and non-commercial sellers; proponents’,
organisers’ and sellers’ awareness and assessment of
stress and welfare at markets; the temporary nature of
markets; and unusual species.
Our study found that:
l Animal welfare – the type and high prevalence of
behavioural signs of stress observed at exotic pet
markets show that a significant and major repre -
sentation of both amphibians and reptiles at these
events are stressed. This indicates that significant
animal welfare problems are associated with exotic pet
markets and that current key concerns are justified.
l Human health– the established nature of amphibians
and reptiles as a reservoir of known pathogens means
that all animals, their containers, seller facilities, and
the sellers themselves must be regarded as potential
sources of zoonotic pathogen contamination. Indeed,
we postulate that it would be reasonable to conclude
Amphibian and reptile pet markets in the EU –An investigation and assessment 5
Arena, Steedman and Warwick, 2012
INTRODUCTION
considerations, and these refer to physical, physiological,
functional anatomical, psychological and behavioural
GENERAL issues. ‘Biological needs’ may be complex and often subtle
and extend beyond basic warmth and nutrition to include
Wildlife markets occur in several regions of the world and providing for appropriate mental stimulation and
take different forms. According to region, wildlife markets behaviour. Relatedly, the spatial needs of animals,
offer animals for various reasons including culinary, important thermal ranges, chemically stimulating surr-
medicinal, and pet purposes. oundings, and many other positive factors may contribute
to good animal welfare.
In Asia, these events tend to be open or partly open ‘street’
markets (also sometimes referred to as ‘wet markets’) Conversely, ‘stressors’ such as handling, photo- (light)
selling a very wide variety of animals including fishes, invasive environments (especially for nocturnal species),
amphibians, reptiles, birds and mammals, as well as small enclosures, single or constant temperature
animal products such as bushmeat (Brown, 2004; Chomel environments, atypical social pressures, and many other
et al., 2007). In North America and Europe, wildlife negative factors may contribute to poor animal welfare.
markets typically involve indoor areas, and the public may
pay entry fees to gain access in many examples (Brown, Amphibian and reptile sellers, breeders, and keepers are
2004; Warwick, Toland and Glendell, 2005; Colazzi, 2004; well known to interpret signs such as animals being ‘good
Warwick, 2006; Chomel et al., 2007; Karesh et al., 2005). feeders’, having ‘good bodyweight’ and manifesting
‘active reproduction’ as being indicators of good welfare
In Asia and some parts of North America, wildlife markets and adequate housing conditions. However, these signs
commonly involve culinary, medicinal and pet purposes, are poor indicators of welfare that in the absence of an
whereas in Europe these events appear most commonly appropriate range of other indicators may be highly
aimed at the pet industry (Warwick, Toland and Glendell, misleading (Broom & Johnson, 1993). Also, the presence
2005; Warwick, 2006; Karesh et al., 2005). of ‘positive’ indicators, even in the presence of broader
positive signs, should not be presumed to convey good
The present report will focus on wildlife markets and welfare where any concomitant negative health or
issues as they relate to the sale of pets, with an emphasis welfare sign is identified (Warwick, 2004a).
on events within the European Union (EU).
A major issue of concern is that amphibian and reptile
Wildlife markets have attracted interest and concern from sellers and keepers, along with many professionals
both the scientific (including biological, veterinary and including veterinarians and biologists, lack the
medical fields) and animal welfare and species protection knowledge-base either to understand the important
communities for several reasons of which three are of biological needs of these animals as they relate to
primary relevance to this report. For this report we welfare as well as the abilities to interpret problematic
focussed on amphibians and reptiles as pets. behaviours that are to an experienced observer readily
identified and understood (Warwick, 2004a).
Animal welfare
Scientific assessment of stress as a measurement of
Animal welfare is reported to be poor at these events welfare broadly fits into two camps, physiological and
(Warwick, Toland and Glendell, 2005; Warwick, 2006), and behavioural.
in the UK, for example, the selling of pets at markets is
unlawful for this reason (Warwick, Toland and Glendell, Physiological measurement typically involves obtaining
2005; Warwick, 2006; Toland, 2006). The view that wildlife blood samples from animals and examining particular
markets are centres of poorly or unregulated trade is also parameters of (commonly) corticosterone, which is a
frequently cited (Colazzi, 2004; Toland, 2006; Warwick, steroid hormone associated with adrenal gland function
2006). Poor husbandry and other practices are indicated and a component of a complex interaction and response
as leading to animal suffering (for example, Warwick, to stress (Guillette et al., 2004). The ‘adreno-
2004a; Toland, 2006). corticosterone’ response to stress is considered to be
associated with a form of pain- and other trauma-
It should be presumed that amphibians and reptiles, like reduction/modifying mechanism. In other words, an
other animals, are sensitive to aversive stimuli (pain, animal that is stressed by an event (including capture and
trauma) (Cooper, 1989). Environmental stressors, includ - handling) produces this physiological response that
ing physical (such as thermal and humidity extremes and consequently acts to control the trauma involved.
irregularities) as well as psychological and behavioural are Physiological stress is naturally associated with acute
also important considerations (Arena & Warwick, 2004; stress ‘survival’ scenarios, rather than with chronicstress
Warwick, 2004a). situations (Dickens et al., 2010). Occasional acute stress
episodes, while physiologically demanding, are tolerable
Animal welfare and its assessment are based on biological within the context of health and welfare whereas chronic
6 Amphibian and reptile pet markets in the EU –An investigation and assessment
Arena, Steedman and Warwick, 2012
stress is associated with the dysregulation of the acute is that there is a decrease in sex steroids leading to
stress response and results in increased ill-health reduced reproductive success (Guillette et al., 2004).
vulnerability and pathology (Dickens et al., 2010). These general findings in some respects are consistent
with the common view that reproductively successful
Many researchers adopt physiological measurements as animals are unlikely to be experiencing stress-related
a guide to stress-levels in animals. This is particularly raised corticosterone levels. However, this association
notable where laboratory animals are concerned as well allows very limited conclusions to be reached about an
as when monitoring wildlife during translocation. animal’s psychological and behavioural condition
Assessing stress in a typical clinical, zoological or pet because many reptiles with successful reproductive
animal context commonly involves behavioural rather histories both manifest captivity-related pathologies
than physiological measurements. (Frye, 1991) and captivity-related stress behaviour
(Broom & Johnson, 1993; Warwick, 2004a).
There are, however, some important drawbacks to using
physiological measurement in the assessment of stress Behavioural measurement typically involves observing
in animals, including amphibians and reptiles. Among what animals do and, in the context of welfare, assessing
these is the issue that there appear to be few detailed what behaviour is normal or abnormal. Normal
data on physiological values in undisturbed free-living behaviour includes not only behaviours known to be part
amphibians and reptiles. Accordingly, reliable baseline of an animal’s life in nature, but also to form a balanced
information important to formulating comparative component of a range of behaviours that reflect the
analysis is lacking or absent in very many scenarios. species natural history. For example, in nature it may be
Also, the basic ‘bias’ influence exists that obtaining a normal and healthy for an animal to spend hours of
physiological sample (often via blood) is itself an exploratory locomotor activity in order to hunt for prey,
invasive procedure that causes a physiological reaction. whereas it may be abnormal and unhealthy for an animal
Non-invasive techniques are available, such as analysis to spend even far less than one hour pacing a small
of faecal samples from free-living and captive animals enclosure in captivity with plentiful food.
(Harper et al., 2011) and these can provide ‘purer’
comparative data. However, it remains unclear whether Certain stressors are not absent in nature, rather they
life habit differences, such as in diet and season–related occur commonly. However, stressors in nature are
hormonal condition, between wild and captive animals typically contextualised within a functional and overall
results in mismatched sample values. positive process, in other words they ‘come and go’,
contribute to awareness and other useful factors, and are
Studies of the human cortisol response (cortisol is the balanced by life in an environment that has an over-
human equivalent of corticosterone in amphibians and arching suitability. By contrast, captive conditions
reptiles) allow both objective and subjective analyses to typically replace many parameters of the natural world
be performed, rather than purely objective analyses in with artificial and frequently poorly matched alternatives
animals. Human studies report that cortisol may be that deprive animals of known normal behaviour and
mediated by mood (for example, agitation-related associated biological needs, such as hunting, spatial
stimuli) whereas states including perceived stress, range, and habitat variation (Warwick, 2004a). The
anxiety, and depression may not increase cortisol assessment of normal and abnormal behaviour, there -
(vanEck et al., 1996). On this basis, states such as under- fore, offers greater holistic opportunities for the
stimulation in amphibians and reptiles may not be assessment of welfare. Abnormal behaviours indicate
revealed through physiological measurement, which is that ‘something is wrong’ with the present environment,
consistent with the results of behavioural assessment. regardless of what narrow physiological data emerges
from selected blood or faecal sampling.
Further, corticosterone measurement represents a very
narrow marker (commonly linked in the reptile research Generally, captivity-related chronic stress behaviour
field to reproductive fitness) in the extremely diverse may result in increased abnormal behaviour,
and dynamic internal physiological environment of an behavioural inhibition, vigilance behaviour, hiding,
organism. Also, varied physiological responses from a fearfulness and frequency of startle, aggression, and
diversity of, for example, reptile species illustrate a risk freezing behaviour, and decreased exploratory
in extrapolating information regarding adrenal function behaviour, reproductive behaviour, behavioural
(Jones & Bell, 2003). While corticosterone measurement complexity, and latency to freeze as summarised in
may be revealing of certain types of stress and stressor, Morgan and Tromborg (2007). However, these criteria
and of its associations with particular physiological are subject to various differences according to animal
states, there is little scientific evidence to support the class and species. We have adopted established
use of physiological measurement for the assessment behavioural assessments and, as stated elsewhere in
of amphibian and reptile welfare in a holistic context. this report, included amphibian- and reptile-specific
behavioural target signs as summarised in Warwick
A common finding in ‘physiologically stressed’ animals (2004a) and Warwick, Lindley and Steedman (2011).
Amphibian and reptile pet markets in the EU –An investigation and assessment 7
Arena, Steedman and Warwick, 2012
While not seeking to detract from the value of The United States Government Accountability Office
physiological monitoring, behavioural assessments are (Anon, 2010b) recently completed a survey of major
well-established and non-invasive criteria for the authorities and scientists variously involved in border
evaluation of stress and, we maintain, more reliable protection and prevention of potentially harmful
indicators of normality and abnormality. pathogens entering the US. The risks from zoonotic and
animal diseases associated with live animal imports
Proponents, organisers and sellers associated with (including exotic pets) were a key feature in both the
wildlife markets have claimed that the animals kept and remit and the recommendations.
offered for sale at the events are caused no stress (Anon,
2010). Relatedly, proponents also claim that the It is believed that epidemics such as SARS (Severe Acute
temporary nature of the markets (commonly one-day Respiratory Syndrome), monkey-pox, and avian
sales) means that the short-term housing and influenza H5N1 may have emerged from wildlife
minimalistic provisions typically associated with these markets (Brown, 2004; Warwick, Toland and Glendell,
animals is acceptable (Anon, 2010). These two claims 2005; Warwick, 2006; Warwick, 2006; Karesh et al.,
are central justifications for proponents, organisers and 2007; Burgos & Burgos, 2007). The arbitrary mixing of a
sellers associated with European pet markets in respect wide variety of species that would not normally meet
of the counter-criticisms concerning animal welfare. together in conditions of highly questionable animal
husbandry and public health protection measures raise
Human health multifactorial concerns about these markets and their
effects on animals, people, species conservation, and
Human health is reportedly a key concern at wildlife the environment (Warwick, Toland and Glendell, 2005;
markets due to the attendance of the public, because Warwick, 2006; Warwick et al., 2006; Chomel et al.,
many animals are likely to harbour transmissible 2007; Karesh et al., 2007; Burgos & Burgos, 2007).
pathogens (Warwick, 2004b, 2006). Pathogenic infections
and infestations transmissible from animals to humans Nations that currently permit exotic animals to be traded
are known as zoonotic diseases or zoonoses. There are and kept in their homes likely already face significant
around 200 zoonoses (Krauss et al., 2003), and approx - public health-related issues arising from this practice but
imately 40 of these are associated with amphibians and epidemiological ‘under ascertainment’ (a lack of formal
reptiles (for examples, see Appendices 1 & 2). recording and recognition of relevant issues) may occur
concomitantly and ‘mask’ problematic prevalence.
Captive reptiles are routinely identified as reservoirs of Numerous zoonoses symptomatically superficially
certain bacteria, for example Salmonella (Geue & resemble common illnesses such as gastrointestinal,
Löschner, 2002) and all reptiles should be presumed to respiratory, influenzal, and dermatological disease.
harbour Salmonella (Ward, 2000; Mermin et al., 2004; General medical practitioners may be unfamiliar with
Brown, 2004; Warwick, Toland and Glendell, 2005; zoonoses and do not typically enquire of patients about
Warwick, 2006; Warwick et al., 2006; Burgos & Burgos, direct or indirect contact with an exotic animal (Warwick,
2007). 2004b). Zoonoses may be mild, moderate or severe in
their symptoms and outcomes.
Relatedly, epidemiological surveys in the United States in
the 1960s and 1970s showed that approximately 14% of Significant case numbers of zoonotic disease arise from
all cases of human salmonellosis were associated with indirect contact with an animal—that is, contamination
the keeping of pet baby terrapins (called ‘turtles’ or that does not transmit directly from animal-to-human
‘sliders’ in the US) (Lamm et al., 1972). As a consequence but instead transmits from intermediary surfaces such
of those studies US agencies formally described the trade as door handles, clothes, table tops, walls, household
in pet terrapins as a “significant” and “major” threat to utensils, shaking of hands, and so on (Anon, 1995;
public health, and banned the primary national trade in Mermin et al., 1997; Warwick et al., 2001). Accordingly,
terrapins under 10cm (4”) in 1975. Prior to the 1975 ban, an affected person may be unaware that they were
the pet baby terrapin trade constituted approximately 14 infected by an inanimate object or by another
million animals per year. That prohibitive action resulted individual. In such cases, even if asked by medical staff
in a 77% reduction in relevant human salmonelloses about their habits in relation to exotic animals, the
cases in the following year (Mermin et al., 2004). patient may genuinely not be aware of this indirect
contact. Also, doctors frequently make little or no effort
More generally, a survey of 1,410 human diseases to source-trace an infection or infestation and a
found 61% to be of potentially zoonotic origin (Karesh potential epidemic may long go uncontrolled.
et al., 2005). Brown (2004) states that 75% of global
emerging human diseases are zoonotic. Jones et al. An additional consideration relating to the prevention and
(2008) found that over 60% of emerging infectious control of diseases acquired from amphibians and reptiles
diseases are zoonotic, and that almost 72% of these involves the issue that unlike endotherms (birds and
originate from wildlife. mammals) that procedurally undergo 30 days compulsory
8 Amphibian and reptile pet markets in the EU –An investigation and assessment
Arena, Steedman and Warwick, 2012
quarantine designed to identify, in particular, threats such Proponents, organisers and sellers associated with
as rabies and exotic Newcastle disease, ectotherms wildlife markets have claimed that public health risks
(amphibians and reptiles), despite harbouring a vast array are minimal and that the use of sanitising products
of human and agricultural pathogens undergo no such as gels and sprays provide adequate control
quarantine. This system allows for the rapid importation against infection (Anon, 2010b).
of amphibians and reptiles, especially where transport -
ation by air is concerned (Warwick, 2006). The purchase of Invasive alien species
exotic animals from wildlife markets enables diverse
pathogens direct access to the domestic environment via Ecological issues including species conservation and risk
sellers and keepers ignorant or disregarding of salient of introducing invasive alien species derive from the
contaminant transmission issues. presence of wild-caught animals at markets, reports of
taxonomically novel species on sale, and also because of
The presumed primary transmission route for many the particularly casual manner of animal sales that may
amphibian- and reptile-borne potential pathogens is result in unwanted animals escaping or being
faecal-oral ingestion (Lamm et al., 1972). However, human abandoned (Warwick et al., 2006; Toland, 2006).
skin scratches from the claws of lizards (Frye, 1995) or
chelonians, and bites from snakes and lizards also may In addition to climate change, overexploitation,
transmit contaminants (Frye, 1995; Warwick et al., 2001). pollution and habitat destruction/modification,
Also, direct contact between any contaminated reptile invasive alien species (IAS) are considered to be one of
and open human lesions, such as sores, or via reptile the major threats to the natural biodiversity of Europe
debris penetrating human orbital (eye) or aural (ear) sites (Shine et al., 2010). Invasive alien species are non-native
are further potential routes of infection (Warwick et al., species of animals and plants that, once introduced and
2001). Aquatic turtles may contaminate large bodies of established, cause widespread destruction with
water—resulting in contaminated splashes, droplets, and negative economic, social and environmental impacts
smears that may lead to human infection; lizards are (Shine et al., 2009; Keller et al., 2011).
handled more than turtles and are more likely to
introduce infection via skin scratches; and snakes may be Through direct or indirect methods, IAS may
handled far more frequently than lizards and thus may compromise human health and are responsible for
spread contaminants more widely and consistently. hundreds of billions of dollars in economic damage and
Diverse surfaces may act as intermediary carriers of many ecosystem management around the world (Strayer et
biotic contaminants and once a surface is contaminated al., 2006). In the European Union (EU) it has been
potential contagions may long persist. estimated that the annual cost of damage from IAS is
approximately €12.5 billion (European Commission,
Hand washing and the use of disinfectant gels and sprays 2011). This is up from a figure of around €10 billion
are commonly recommended and perceived as sufficient reported just a few years earlier (European Commission,
hygiene measures to eradicate Salmonellaand any other 2008). These figures likely are gross underestimates of
potential pathogens (Warwick et al., 2001). However, the actual cost of damage caused by IAS simply
these hygiene methods as generally practiced do not because, for much of Europe, the extent of damage is
provide reliable protection against diverse amphibian- unknown. Furthermore, as will be pointed out later, it is
and reptile-borne contaminants. Indeed, the use of these likely that the true impact of IAS and the associated
materials and methods generates undue over-reliance costs will remain unknown for a number of years (or
and misplaced confidence in personal disease prevention even decades) – a period known as a ‘lag’ phase (Keller
and control that may lead to infection from complacency et al., 2011). Indeed, Vilà et al. (2009) pointed out that
(Warwick, Lindley & Steedman, 2011). For example, in the above figures most likely represent approximately
order to adequately cleanse human hands alone rigorous 10 percent of real figures.
hand-washing protocols comparable to that among pre-
theatre surgeons would need to be adopted and even Across Europe, the economic value of losses from IAS, in
here such measures are not wholly reliable and terms of species and biodiversity loss and impact on
practically impossible in both the wildlife market and the areas such as forestry, fisheries and tourism, are also not
domestic environments. readily available (Shine et al., 2009). However, with
respect to species diversity alone, of the 174 European
Relatedly, contaminants are easily spread over diverse species listed as critically endangered by the IUCN
surfaces including the individual’s clothes (including (International Union for Conservation of Nature) Red
pockets), hair and skin, as well as inanimate objects and List, 65 are in danger as a result of IAS. Despite proposed
other people around them (Warwick, et al., 2001). initiatives to target biodiversity loss in 2001, currently
Accordingly, even theoretically‘sterile’ hands are subject only 17% of European habitats and species and
to rapid re-contamination via momentary contact with approximately 10% of key ecosystems are in a state
any previously touched and thus contaminated item or referred to as “favourable” (European Environment
area (Warwick et al., 2001). Agency, 2010).
Amphibian and reptile pet markets in the EU –An investigation and assessment 9
Arena, Steedman and Warwick, 2012
The complexity of IAS issues is such that the effects not and is currently sold in pet shops and wildlife markets
only are often difficult to detect, but also the impacts across Europe.
may be both direct and indirect. Direct impacts may
include competition with local species for both food and It cannot be denied that the exotic pet trade is a major
habitat for which the results are often quite visible and contributor to the introduction and establishment of
relatively straightforward to deal with. However, IAS (Keller et al., 2011). While not suggesting that
indirect impacts are often more complex and difficult to amphibians and reptiles make ‘good’ pets it is
deal with as they may result in a series of ‘flow-on’ reasonable to assume that just as certain biological
effects. One example is when the introduced invading features of these species (such as dietary and in some
organism acts as a host for potentially destructive examples thermal plasticity) renders them attractive,
pathogens. For example, the American bullfrog Rana these traits arguably also equip these animals with the
catesbeiana is responsible for the decline of many means by which they are able to establish themselves,
amphibians in Europe through direct competition for should they enter a foreign habitat either accidentally
food and habitat, but also indirectly, through the or intentionally.
introduction of Batrachochytrium dendrobatidis, which
causes chytridiomycosis, a fungal disease responsible Ironically, despite the recognised destructive potential
for the extinction of approximately 200 species of of IAS, the management of these species in Europe, prior
amphibian worldwide (Ficetola et al., 2007; Fisher et al., to 2010, was not guided by clearly established policy
2009; Skerratt et al., 2007). Indirect impacts may also be (Shine et al., 2010). Furthermore, the lack of coordina -
extremely difficult to monitor as the process may tion governing approaches to the issue of IAS in the
involve a series of subtle changes over a long period of European Union has been described as a “serious
time such as when the presence of an invasive species shortcoming” (Keller et al., 2009).
as predator or prey (or both) alters the myriad of
dependencies within a food web. There have been attempts at producing legislation that
would restrict the trade in potentially invasive alien
It is clear that IAS have significant negative impacts on species. This includes ‘black lists’ of species as proposed
many native species and almost all ecosystems that they in Council Directive 2000/29/EC. However, there is
invade. The brown tree snake Boiga irregularisof Australia much disagreement between countries as to which
and Papua New Guinea, through accidental introduction species should be included on black lists. Moreover, key
in the 1950s, has caused millions of dollars worth of stakeholders (eg the pet trade, animal breeders) have
economic damage and decimated the endemic fauna of actively opposed greater regulation and control of the
Guam. This IAS has thrived in response to the lack of importation, holding and movement of exotic species,
natural predators and abundance of prey items, impacting for example, HR 669: The Non-native Wildlife Invasion
on the island’s ecology and economy, affecting human Prevention Act. In response, Warwick, Arena and
health (through serious snake bites) and causing power Steedman (2009) rejected the introduction of ‘positive
blackouts whilst foraging on power lines (Johnston et al., lists’ of introduced species that could be kept by
2002). The cane toad Bufo marinus, another opportunistic individuals and, instead, recommended the continued
generalist feeder, was intention ally introduced into restriction on the exotic pet trade and live keeping of
Australia in the 1930s as a form of biological control that amphibians and reptiles in Norway.
failed. The amphibians multiplied and are now well
established in northern Australia, directly impacting upon Following the tenth Conference of the Parties (CoP10)
populations of larger predators such as varanid and to the Convention on Biological Diversity (CBD), held in
scincid lizards, elapid snakes, freshwater crocodiles and Nagoya in 2010, the EU 2020 biodiversity strategy was
carnivorous marsupials (Shine, 2010). The cost of damage developed, which included a target aimed at
resulting from the direct and indirect impact of this “promoting a more resource efficient, greener and
species has not yet been quantified. more competitive economy” including addressing the
issue of biodiversity loss across Europe
In Europe, it has been estimated that more than 50 (http://ec.europa.eu/environment/nature/biodiversity/
species of amphibians and reptiles have become comm2006/pdf/2020/1_EN_ACT_part1_v7%5B1%5D.p
established (Kark et al., 2009). Of these, the African df). Target 5 of the Conference document is dedicated to
clawed frog Xenopus laevis (widespread throughout combating invasive alien species and includes
many US states) has been recorded in established strengthening animal health regimes. A further step in
populations in Wales (Measey & Tinsley, 1998) and is a positive direction is the development of the DAISIE
known to be spreading through Portugal (Rebelo et al., (Delivering Alien Invasive Species Inventories for
2010). Xenopus, in addition to being a voracious and Europe) project – a website inventory designed to
aggressive feeder in a similar way to Rana catesbeiana, provide the most up-to-date information on alien
is another known host of Batrachochytrium invasive species across Europe (see http://www.europe-
dendrobatidis (Skerratt et al., 2007). Regardless, this aliens.org/). According to DAISIE, more than 11,000
species is still promoted as an ideal ‘beginner’s frog’ invasive species have entered Europe.
10 Amphibian and reptile pet markets in the EU –An investigation and assessment