To kill or not to kill—Practitioners’ opinions on invasive alien species management as a step towards enhancing control of biological invasions

Environmental Science & Policy 58 (2016) 107–116

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To kill or not to kill—Practitioners’ opinions on invasive alien species management as a step towards enhancing control of biological invasions
ska* , Wojciech Solarz, Kamil Najberek Agnieszka Olszan Institute of Nature Conservation, Polish Academy of Sciences, Mickiewicza 33, 31-120 Krakow, Poland

A R T I C L E I N F O

A B S T R A C T

Article history: Received 2 July 2015 Received in revised form 11 January 2016 Accepted 12 January 2016

The spread of invasive alien species (IAS) has become an increasingly important environmental, social and economic issue in almost all regions of the world. To have the capacity to effectively counter the effects of invasions, besides basic research on invasion processes and the ecological impacts of IAS, there is a need to get an information and better understanding of the effectiveness of biological control and its social acceptability. Conservation practitioners are a particular group of stakeholders as they act in the first line to undertake control actions again IAS spread. Yet, not many research was done to deliver quantitative, comprehensive information on practitioners’ knowledge and attitudes towards IAS. In this paper, we present a study from Poland—a country with relatively well preserved nature, yet currently facing the problem of biological invasions in the terrestrial and aquatic environments. We investigated nature conservation practitioners’ knowledge of biological invasions, their views on the principles and methods of IAS control, and their degree of acceptance of control methods. We conducted a survey among people professionally involved in nature conservation in Poland and collected 916 questionnaires (out of 3330 sent). Overall, we find that conservation practitioners in Poland accept the use of radical methods of control, yet they differ about the use of various types of control method, and about the various control methods application to various systematic groups. Also, the level of practitioners’ knowledge is rather limited—both in relation to correct identification of IAS, as well as to knowledge on legal regulations. We also highlight significant differences between decision-makers and professionals not perceiving themselves as decisive over IAS management. We show examples suggesting that nature conservation practitioners may not hold well-formed opinions on the principles and methods of dealing with alien species. This is surely an important deficit to overcome to enhance the effectiveness of IAS control. ã 2016 Elsevier Ltd. All rights reserved.

Keywords: Invasive alien species Management Control Acceptance Opinions Practitioners

1. Introduction Scientists and wildlife managers alike state that preventing new introductions of alien species is the most effective way to reduce biological invasions (McNeely, 2001; Zavaleta et al., 2001; Genovesi and Shine, 2011; Sharp et al., 2011). However, prevention is not always successful, and control measures have to be taken as the second line of defense after introduction. Controversial measures, including “shoot first and ask questions later” approach, often remain the only practicable option (Zavaleta et al., 2001; Simberloff, 2003; Genovesi and Shine, 2011; Genovesi, 2005; Brown et al., 2008). While radical eradication measures have

* Corresponding author at: Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120 Krakow, Poland. Fax: +48 12 6322432.
ska). E-mail address: [email protected] (A. Olszan http://dx.doi.org/10.1016/j.envsci.2016.01.008 1462-9011/ ã 2016 Elsevier Ltd. All rights reserved.

proven effective, they are still rarely applied, mainly due to ethical concerns (Genovesi, 2005; Minteer and Collins, 2005; Lundberg, 2010; Vanderhoeven et al., 2015). As recommended by strategies, guidelines and codes of conduct (IUCN Council, 2000; Genovesi and Shine, 2011; Davenport and Collins, 2011; Heywood and Brunel, 2011; Scalera et al., 2012; ALARM project http://www. alarmproject.net/alarm) and proven in practice (Bertolino and Genovesi, 2003; Stokes et al., 2006; Fischer and Young, 2007), the success of alien species control programs depends both on the level of public acceptance and on the effectiveness of control methods. In Western Europe, proposals to employ radical alien species control have caused long debates and even public protests, especially when they targeted species that benefit from sympathy of the general public, such as the ruddy duck Oxyura jamaicensis or grey squirrel Sciurus carolinensis (Bertolino and Genovesi, 2003; Stokes et al., 2006).

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Despite such lessons, many alien species control programs still focus more on technical than social aspects, such as public perceptions, the knowledge and potential involvement of society or selected social groups (Coates, 2006; Gozlan et al., 2013; Urgenson et al., 2013). This may be a consequence of the fact that little is known about awareness and attitudes towards the IAS problem, not only among the general public but also among nature conservation professionals (Garcia-Llorente et al., 2008; Andreu et al., 2009). This knowledge is indispensable to effectively counter the effects of biological invasions (Sharp et al., 2011) and bridging the knowing-doing gap have been risen as one of the most important challenge in conservation science (Bay-Larsen, 2012; Hulme Ph, 2014). The in-depth knowledge of practitioners’ awareness, knowledge and attitudes is crucial is a first step towards diminishing this gap. In a number of studies, covering Scotland (Bremner and Park, 2007; Fischer et al., 2014), Spain (Garcia-Llorente et al., 2008; Andreu et al., 2009), Norway (Lundberg 2010), New Zealand (Farnworth et al., 2014) or South Africa (Ntshotsho Ph Prozesky et al., 2015), the majority of respondents, both practitioners and members of the general public, considered control of IAS to be the most effective method of dealing with the problem of invasions, considering control as both, non-lethal (e.g. removal of plants, use of repellents, exclusion fences) and lethal methods (e.g. trapping, shooting, poisoning). At the same time, most respondents were skeptical about the radical, lethal methods of control. An interesting and rarely studied aspect is the link between the awareness of the control method efficiency, the decision making process and on-the-ground decisions made by practitioners who actually implement IAS prevention or control programmes. Due to its geographical location in Central Europe, covering continental, Baltic and Carpathian biogeographical regions, Polish territory has been an important gateway and stepping-stone in the past for a number of westwards invasions of alien species to Europe. Examples of terrestrial invasions for which Poland was an early stepping stone in their conquer of Europe include American mink Neovison vison and Raccoon dog Nyctereutes procyonoides (Solarz 2011). Poland is also the part of the central European invasion corridor allowing aquatic aliens of Ponto-Caspian origin to spread westwards to the Baltic basin. Past invasions include the very invasive round goby Neogobius melanostomus and zebra mussel Dreissena polymorpha, and a number of new species are expected to profit from this man-made expansion pathway in near future (Semenchenko et al., 2011). Poland’s geopolitical location is also crucial in this respect, as the country holds a large share of the outer EU border. This makes it particularly responsible for the successful implementation of the new EU Regulation on IAS (Regulation No 1143, 2014). Thus the level of awareness and attitudes of Polish nature conservation practitioners towards the IAS-related issues appears to be crucial not only as the first line of defense for the local nature, but also from the European perspective. A few studies (Najdenowa, 2006; Najberek and Solarz, 2011) in Poland indicated that the level of awareness of biological invasions is alarmingly low among the general public and practitioners alike, and that there is a significant resistance against the use of radical measures of alien species control. In this study we present an in-depth analysis of the level of nature conservation practitioners’ knowledge of biological invasions, their views on the principles and methods of IAS control, and the level of their acceptance. We targeted our research at professionals and amateurs involved in nature conservation in Poland, especially those in a position to affect the implementation or directly implement alien species control programs at the country, regional and local levels. We were specifically interested in the decision-taking aspect, thus the respondents were asked to

declare if they possess a mandate to take decisions on IAS control. The aim of the study was also to determine if and how the level of acceptance of radical control measures differs between those who declare taking responsibility for the decisions on IAS management. 2. Materials and methods 2.1. Sampling and data collection In this research we targeted professionals and amateurs who potentially may take decisions about IAS management, including scientists, wildlife managers (state officials from local to national level), officials at the Ministries of Environment and Agriculture, staff of national and landscape parks, staff of the State Forests (National Forest Holding) and agricultural advisory centers, managers of zoological and botanical gardens, and members of NGOs dealing with nature conservation, such as the Polish Hunting Association and Polish Angling Association. Respondents (particular persons within each institution) invited to participate in the survey and then they were sent the questionnaire by e-mail (n = 2569) or by post (n = 761). Information was collected from March to August 2012. We received 952 responses, of which 916 (28.6% return rate) were completely filled-in questionnaires (paper and internet versions) used for the analyses. 2.2. Questionnaire design Both the 8-page paper questionnaire sent by post, and its online version started with an introduction briefly explaining five terms commonly used in invasion biology: native species, alien species, invasive alien species, control and eradication (“control”1 was used as a synonym for the process of eradication or reduction in size of IAS) of alien species. The first section of the questionnaire (7 questions) included general socio-demographic information about the respondent: age, gender, education and residence, and a question on membership in any NGO dealing with nature conservation. The second section (9 questions) asked about the respondent’s involvement in management and current knowledge about nature conservation, and issues related to IAS in Poland (including legal aspects and management). In the third section (15 questions) the respondents were asked their opinions on IAS management. The last section included questions on management options for 22 invasive alien species which, according to the Alien Species in Poland database (http://www.iop.krakow.pl/ias/) constitute a serious threat to native biodiversity and/or the economy, and/or are widely distributed in Poland (see supplementary material); the species selected for the survey were easy to identify by a non-expert, and a colour photo of each of these species was provided: Plants: Heracleum sosnowskyi (Sosnowski’s hogweed) Padus serotina (Black cherry) Solidago canadensis (Canada goldenrod) Reynoutria japonica (Japanese knotweed) Impatiens parviflora (Small-flower touch-me-not) Impatiens glandulifera (Himalayan balsam) Invertebrates/arthropods: Leptinotarsa decemlineata (Colorado beetle) Cameraria ohridella (Horse chestnut leafminer)

1 Definition of “control” used in the questionnaire: “control (process of eradication) of an alien species is to remove it from the place of occurrence or reduce its size. Usually requires the use of radical and drastic methods (the killing, trapping cages, use of poisons, herbicides or pesticides, digging). ”


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Harmonia axyridis (Harlequin ladybird) Cercopagis pengoi (Fishhook waterflea) Mnemiopsis leiydi (Warty comb jelly) Pacifastacus leniusculus (American crayfish) Invertebrates/molluscs: Dreissena polymorpha (Zebra mussel) Arion lusitanicus (Iberian slug) Vertebrates: Neogobius melanostomus (Round goby) Hypophthalmichthys molitrix (Silver carp) Trachemys scripta elegans (Red-eared terrapin) Branta canadensis (Canada goose) Ondatra zibethicus (Muskrat) Neovison vison (American mink) Nyctereutes procyonoides (Raccoon dog) Procyon lotor (Raccoon) Most attitudinal items were measured on a 5-point Likert scale, ranging from “strongly disagree” = 1 to “strongly agree” = 5, with a “no opinion” = 3 option in the middle of the scale (Carifio and Perla, 2007). The questionnaire was constructed so that high values indicated positive feelings and low values negative feelings. Knowledge items had multiple-choice response sets and included a “no opinion” or “I don’t know” answer. The questionnaire was anonymous and the respondents were not asked about their profession or place of work. As one of our research goals was to learn how Polish nature conservation practitioners see their decision-making power, respondents were asked whether their duties required taking decisions on IAS management. 2.3. Data analysis The responses were grouped into modules defining knowledge of alien species, opinions on IAS management (for different taxonomic groups), and opinions on the use of various methods of IAS control, including radical ones (for plants: cutting, digging, herbicide use, destruction of seeds and seedlings; for animals: shooting adults, poisoning, pesticide use, anaesthesia, trapping incl. killing traps, sterilization/contraception, destruction of eggs of birds, killing chicks or young mammals in nests, killing pregnant female mammals). Groups of respondents were compared by multivariate analysis of variance, t-tests and regression analysis (Tabachnick and Fidell, 2001). The analyses were performed using SPSS for Windows ver. 20.0.0 (IBM1 SPSS1 Statistics 2011).

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3. Results 3.1. Socio-demographic characteristics of respondents Based on respondents’ answers to the question on whether their job required taking decisions on IAS management, gathered data were divided into three groups: there were 387 (42.2%) “decision-takers” (DT), 474 (51.7%) “non-decision-takers” (NDT) and 55 (6.1%) those who did not characterize themselves in this regard (“no opinion”, NO). We noted a high proportion of male respondents, particularly among the DT group (72.18% male, 27.9% female; Table 1) and a high proportion of persons with higher education (85.2% university level, 14.8% high-school level; Table 1). Almost half (47.3%) were members of NGOs dealing with nature conservation. 3.2. Knowledge of IAS and issues related to IAS management Most of the respondents were familiar with the concepts of “alien species” (98.0%), “invasive alien species” (93.1%), “introduced species” (84.0%) and “biological invasion” (73.7%). Among the issues related to environmental protection and nature conservation, in the multiple choice questions respondents indicated habitat loss (92% of respondents), habitat fragmentation (84%), pollution (92.5%), changes in land management (86.1%) and urbanization (87.8%) as important or very important ones. Biological invasions had the same status for 75.8%, were considered as neutral by 19.2%, and irrelevant to 5% of the respondents. Climate change seemed important or very important to 59.5% of the respondents, 27.8% identified the problem as neutral, and 12.7% as irrelevant. Respondents were also asked an open question to estimate the number of IAS in the Polish flora and fauna. Currently the regularly updated Alien Species in Poland database (http://www.iop.krakow. pl/ias/) lists 1282 alien species recorded in Poland (1229 at the time of the study). The DT appeared to be most knowledgeable in this respect (Fig. 1) and the three groups of respondents differed significantly in their responses (ANOVA, F = 12.19, p < 0.001, df = 2, N = 916), with DT being most correct (Fig. 1). The DT respondents were also most knowledgeable about the Polish legislation connected with alien species. Almost 80% correctly answered 2 questions on legal consequences of unauthorized import of an invasive alien species or introducing

Table 1 Socio-demographic description of respondents who take decisions on invasive alien species management (DT), those not taking such decisions (NDT), and those not characterizing themselves in this regard (NO); sample size and share [%] of respondents’ gender, age, education and place of residence. DT [%] (N = 387)

NDT [%] (N = 474)

NO [%] (N = 55)

total [%] (N = 916)

Gender

Female Male

27.9 72.1

38.8 61.2

38.2 61.8

34.2 65.8

Age

20–29 30–39 40–49 50–59 60–69 >70

12.9 35.1 20.2 21.4 9.0 1.3

19.2 29.7 20.0 20.3 10.3 0.4

20.0 43.6 5.5 16.4 14.5 0.0

16.6 32.9 19.2 20.5 10.0 0.8

Education

Secondary (high school) Higher (university)

12.4 87.6

16.0 84.0

21.8 78.2

14.8 85.2

Place of residence

Rural Urban <50,000 residents Urban >50,000 residents

40.1 22.2 37.7

39.0 28.9 32.1

34.5 36.4 29.1

39.2 26.5 34.3


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Fig. 1. Frequencies of answers [%] to the question about the number of alien species in the Polish flora and fauna, as given by respondents taking (DT) and not taking (NDT) decisions on invasive alien species management, and by those who did not characterize themselves in this regard (NO).

it into the wild, while between 14.6% and 18.6% did not know the answer. The respective fractions among the NDT were 64,3% and 69,8% of correct answers, followed by 31,2% and 26,2% of those who did not know the correct answer. Asked to list 5 alien plant and 5 alien animal species present in Poland in the wild, the respondents provided 325 species (Supplementary material_1—question “Specify five plant alien species that occur in Poland in the wild”, Table 2), of which the most frequent were angiosperms (Magnoliophyta), arthropods (Arthropoda) and vertebrates (Vertebrata). However, only 193 (59.4%) of these species were indeed aliens occurring in the wild in Poland, including the most frequently mentioned American mink N. vison, raccoon dog N. procyonoides, Sosnowski’s hogweed H. sosnowskyi and raccoon P. lotor. For 41 alien species listed by the respondents there are no confirmed records of wild occurrence in Poland; these include the Nile perch Lates niloticus and grey squirrel S. carolinensis. As many as 91 species were listed mistakenly, as they are in fact native to Poland (Table 3). 3.3. Opinions on invasive alien species management The vast majority of practitioners (92.5% of DT, 89% of NDT, 81.8% of NO) agreed with the statement that “Control [=eradication] of certain species of plants and animals (both native and alien) is necessary to protect wildlife”. The respondents were skeptical about the idea that all alien species in Poland should be eradicated in order to protect native species: 59.5% of DT, 49.2% of NDT and 54.5% of NO disagreed with this statement; 25.1% of DT, 25.9% of NDT and 12.7% of NO agreed. These differences between the respondents were statistically significant (H = 8.71, p < 0.013, Kruskal–Wallis test, df = 2, N = 916). Restricting the group of alien species that should be controlled to invasive ones increased the level of support. It remained high

irrespective of the impact of the targeted species: 91.5% of DT, 89% of NDT and 81.9% of NO supported control in case of economic losses in agriculture, horticulture, forestry, etc.; 95.1% of DT, 91.4% of NDT and 85.5% of NO agreed that species threatening human health should be controlled; 96.4% of DT, 92.2% of NDT and 89.1% of NO were in favor of control of alien species causing harm to protected or endangered species. Fewer respondents in all groups felt that control is required for alien species with a negative impact on common native species (82.7% of DT and NDT, 72.7% of NO). The majority of respondents in all three groups accepted the option of using radical methods of control (including killing) for alien plants, invertebrates, fish, birds and mammals (Fig. 2). Practitioners taking decisions on the IAS management expressed the most radical opinions, the three groups differed significantly in their degree of support for control of various systematic groups: plants H = 27.76, p < 0.001; invertebrates H = 26.42, p < 0.001; fish H = 23.42, p < 0.001; birds H = 10.96, p < 0.004; mammals, H = 14.11, p < 0.01 (df = 2, N = 916). The majority of the respondents were skeptical towards considering new invading alien species as a valuable addition to biodiversity in Poland: 62.5% of DT, 58.6% of NDT and 38.2% of NO disagreed with this concept. However, as many as 16.5% of DT, 16.9% and 21.8% of NO would welcome new alien invaders and almost a quarter of the respondents had no opinion on the subject: 20.9% of DT, 24.5% of NDT and 40.0% of NO. 3.4. Opinions on specific methods used to control alien species Most of the respondents disagreed that radical methods of control should never be used, even in case of invasive alien species harmful to biodiversity and/or economy (64.6% of DT, 53% of NDT and 40% of NO). More than a quarter of the respondents (25.3% of DT, 28.5% of NDT, 29.1% of NO) saw radical methods of alien species

Table 2 Number of species per phylum/division/class in case of Vertebrata included in the Alien Species in Poland database, and numbers listed by respondents (Table presents only taxa where at least one species was listed by the respondents). Phylum/division/class

Alien Species in Poland database (1229 species)

Magnoliophyta Arthropoda Vertebrata Actinopterygii Amphibia Reptilia Aves Mammalia Mollusca Platyhelminthes Nematoda Annelida Coniferophyta Chlorophyta Pyrrophycophyta Ctenophora Pteridophyta

476 371 145 37 1 9 72 20 35 28 19 14 10 2 2 1 1

N species listed by respondents Alien occurring in Poland in the wild

Alien not recorded in the wild in Poland to date Native to Poland

86 26 55 19

18 1 11 2 1 4

5 17 14 11 1

4

36 4 46 3 3 21 19 1

1 2 8 2 1 1

9 1

4


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Table 3 Knowledge of alien species occurring in the wild in Poland. Each respondent was asked to list 5 plant and 5 animals. Species that were most often classified correctly (alien occurring in the wild in Poland) are presented, as well as species that were most frequently misclassified (not yet recorded in Poland and native). Species

Species (common English name)

Phylum/ division

Alien occurring in Poland in the wild (N answers)

Neovison vison Nyctereutes procyonoides Heracleum sosnowskyi Procyon lotor Padus serotina Quercus rubra Solidago canadensis Robinia pseudoacacia Leptinotarsa decemlineata Acer negundo Orconectes limosus Reynoutria japonica Impatiens parviflora Dama dama Ondatra zibethicus Trachemys scripta elegans Neogobius melanostomus Cameraria ohridella Streptopelia decaocto Phalacrocorax carbo Sus scorfa Lates niloticus Sciurus carolinensis Ginkgo biloba Fraxinus americana Acer palmatum

American mink Raccoon dog

Vertebrata Vertebrata

619 545

Sosnowski’s hogweed Raccoon Black cherry Red oak Canada goldenrod Black locust Colorado beetle

Magnoliophyta Vertebrata Magnoliophyta Magnoliophyta Magnoliophyta Magnoliophyta Arthropoda

470 462 349 227 225 207 183

Box elder Eastern Crayfish Japanese knotweed Small-flower touch-me-not Fallow deer Muskrat Red-eared terrapin

Magnoliophyta Arthropoda Magnoliophyta Magnoliophyta Vertebrata Vertebrata Vertebrata

165 158 154 152 138 129 114

Round goby

Vertebrata

105

Horse chestnut leafminer Eurasian collared dove Great cormorant Wildboar Nile perch Gray squirrel Ginkgo American ash Japanese maple

Arthropoda 100 Vertebrata Vertebrata Vertebrata Vertebrata Vertebrata Magnoliophyta Magnoliophyta Magnoliophyta

control as unacceptable and the three groups of practitioners statistically differed in this respect (Kruskal–Wallis test H = 10.97, p < 0.004, df = 2, N = 916). On the contrary, they were quite consistent in assessing whether the level of their support for an alien species control program depends on the type of the control method (more humane or less humane): it was irrelevant for 59.7% of DT, 56.3% of NDT and 52.7% of NO.

Alien not recorded in the wild in Poland (N answers)

Native (N answers)

15 7 6 27 23 8 6 5

The vast majority of practitioners supported a variety of control methods for removing invasive alien species of plants, including destruction of seeds and seedlings, digging, and cutting (respectively: more than 80% of DT more of 70% of; almost 80% of NO, Fig. 3). The use of herbicides was much less acceptable, supported by 54.8% of DT and 42.8% of NDT and 47.3% of NO (Fig. 3). Practitioners taking decisions of the IAS management proved to be

Fig. 2. Frequencies of answers [%] to the question on the possibility of controlling (including killing) different taxonomic groups of alien species among respondents taking (DT) and not taking (NDT) decisions on invasive alien species management, and among those who did not characterize themselves in this regard (NO); “strongly agree” and “agree” answers were combined as “agree”, and “strongly disagree” and “disagree” answers as “disagree”.

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Fig. 3. Frequencies of answers [%] to the question on methods of invasive alien species control among: (a) respondents taking (DT), (b) respondents not taking (NDT) decisions on invasive alien species management, (c) respondents who did not characterize themselves in this regard (NO). Statistically significant differences in views are asterisked.


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most radical in their views, the three groups differed significantly in their acceptance of the various methods for controlling plants (cutting H = 13.25, p < 0.001; digging H = 13.24, p < 0.001; herbicides H = 9.44, p < 0.009; destruction of seeds and seedlings H = 12.98, p < 0.002; Kruskal–Wallis tests, df 2, N = 916). The most supported method of controlling adult invasive alien animal species was shooting (DT 77.5%, NDT 67.9%, NO 69.1%), followed by lethal anaesthesia (DT 64.1%, NDT 54.6%, NO 54.5%), and destruction of bird eggs (DT 56.9%, NDT 50.6%, NO 40%; Fig. 3). The differences between the three groups of respondents were statistically significant with DT having higher acceptance for each of the three methods (H = 10.22, p < 0.006; H = 7.28, p < 0.03; H = 8.76, p < 0.01, respectively; Kruskal–Wallis tests, df = 2, N = 916).

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The respondents showed low acceptance of the use of poisons (disagreement: DT 60.7%, NDT 59.1%, NO 52.7%) or pesticides (disagreement: DT 55.7%, NDT 56.5%, NO 50.9%; Fig. 3) and did not differ in their views on those two control methods. They expressed support for sterilization of adult animals (DT 70%, NDT 66.9%, NO 63.6%). Fewer of them accepted trapping, including killing traps (agreement: DT 45.5%, NDT 40.9%, NO 40%; Fig. 3), and did not differ in their opinions on those control methods. The respondents opposed to control juveniles using radical methods. Killing pregnant female mammals was rejected by 67.4% of DT, 69% of NDT and 58.2% of NO. Killing chicks or young mammals was opposed by 58.4% of DT, 63.1% of NDT and 54.5% of

Fig. 4. Opinions on radical control methods (described for animals as killing adult and young individuals, poisoning, pesticide use, and for plants as herbicide use, cutting and digging) used for 22 selected invasive alien species among respondents who take decisions on alien species management (DT) and those not taking such decisions (NDT).

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NO. The respondents did not differ in their opinions on killing pregnant females or killing chicks or young mammals. 3.5. Opinions on the methods used to control 22 selected invasive alien species The general views of the respondents on radical control methods, presented above, were verified by checking the level of their acceptance towards 22 invasive alien species requiring management in Poland, presented in Section 2. The DT and NDT respondents were very radical in their opinions on control of well-known IAS, like Sosnowski’s hogweed, the Colorado potato beetle (L. decemlineata), the harlequin ladybird, zebra mussel D. polymorpha or American mink (Fig. 4). Radical control of other species, especially vertebrates (e.g. Canada goose B. canadensis) was less accepted. The share of respondents who did not have an opinion on radical control of ranged for different species from 5.4% to 41.3% among DT, and from 8.4% to 47.5% among NDT. 4. Discussion There is ample evidence proving that successful environmental management relies strongly on the staff directly involved in its implementation within involved institutions (Sevä and Jagers
ska and Grodzin
ska-Jurczak, 2015). Public 2013; Pietrzyk-Kaszyn support, both among the general public and among nature conservation managers, is particularly crucial to the success of invasive alien species management (Bremner and Park, 2007; Fischer et al., 2014; Humair et al., 2014). There is no dearth of examples showing that effective control of biological invasions requires cooperation among various social groups: experts and researchers, institutions and individuals responsible for national legislation, wildlife managers, and not least the general public, the users of natural resources (Gosling and Baker, 1989; Genovesi, 2005; Stokes et al., 2006; Bonesi et al., 2007; Brown et al., 2008; Garcia-Llorente et al., 2008; Andreu et al., 2009; Fischer et al., 2014). Despite moderate response rate (28.6% returned), the results of this study provide an important insight into practitioners knowledge and perception of the problem of biological invasions, highlighting the need for more confidence and conviction among those who implement conservation and management. The results of our survey indicate general support for radical control of IAS. However, it does not translate into practical actions, not only because of lack of legal regulations or implementation documents. Although increase the level of awareness has become a cliché recommendation is in many similar studies, we claim that the awareness of the issue of biological invasions is in fact satisfactory. What is lacking, is the implementation of control programmes. This is becoming particularly crucial also in Poland, as the European Parliament and the Council has recently accepted the Regulation on the prevention and management of the introduction and spread of invasive alien species (Regulation No 1143, 2014). In order to implement national and European obligations successfully, nature conservation practitioners need to have unanimous attitudes on the IAS management and control handling. We therefore concentrated our study on nature conservation practitioners, as they are on the front line of IAS management on the local scale. We also considered nature conservation practitioners to be professionals understanding the significance of the issue and the responsibility of their decisions and actions, thus motivated more by facts than by emotions. Invasion biology is a relatively new issue for all stakeholders dealing with nature conservation, both governmental and non-governmental (Young and Larson, 2011). We surveyed practitioners implementing and responsible for

nature conservation and thus theoretically most educated in the field of biological invasions. We observed that although they were aware of the issue and they agreed with the need for the prevention of IAS spread, their basic knowledge on IAS species occurring in Poland, legal implications, control methods was insufficient. However, as it was stated by Humair et al. (2014) knowledge of the scientific facts related to biological invasions is just one of the many factors influencing attitudes and opinions of the professionals and stakeholders dealing with IAS. Bearing in mind that we questioned professionals and amateurs involved in nature conservation and nature management, 42% of whom declared that they take decisions on invasive alien species, it is worrying that a quarter of the decision-takers and almost half of the non-decision-takers gave “no opinion” answers. This findings follow those by Humair et al. (2014), where almost a third of invasion biology experts could not recall effects of non-native invasive species on the ecosystem services. This indicates that wildlife managers do not have explicit opinions about the ways, methods and principles of dealing with alien species and that there is clear lack of communication of scientific findings into practical applications. Although most of the respondents did declare that they were familiar with terminology related to biological invasions, all three studied groups underestimated the number of alien species occurring in Poland in the wild, or mentioned alien species that have never been reported from Poland, or mistook native species for alien ones. The last fact might be the result if the increase of some local populations of for example great cormorant Phalacrocorax carbo, or wild boar Sus scorfa, and thus they are sometimes referred to as “invasive” in public discourse; no doubt this helps explain why some respondents considered them as alien species. There is a clear need, therefore, for a better communication and awareness raising among these key stakeholders. In New Zealand, the country that early reacted to the raising issue of invasive alien species spread, researchers noted high sense of responsibility for their unique native flora and fauna. The majority of respondents in New Zealand declared the need for “extermination” of most invasive species (like e.g. possums), yet they showed an utilitarian attitude declaring they would prefer some commercial use of the killed animals, over the “kill-to-waste” option (Fraser, 2001; Allen and Lee, 2006). Although the studied inhabitants of New Zealand accepted shooting and poisoning as the IAS management options, the clear majority expected humane treatment of animals, even if they were defined as “pests”. In our study, we concentrated on nature conservation professionals, and our data demonstrate significant differences between the studied groups. The decisiontakers generally seemed to have more thoughtful opinions and clear preferences regarding the IAS management, with significantly fewer “no opinion” answers than in the non-decision-taker group. While all three groups strongly supported control (defined as process of eradication or the reduction of number) of invasive alien species, the respondents having the power and duty to make decisions expressed significantly stronger support for radical control methods. The respondents differed also in their support for application of radical control to various systematic groups: it was definitely accepted for plants, invertebrates and molluscs, whereas less supported for birds and mammals. This is consistent with results by Veitch and Clout (2001) and Bremner and Park (2007), who found that the public was less supportive of eradication of alien species of considerable size (like mammals) or attractiveness (like rhododendron). In the studies on the Scottish public, respondents also differed in their support for methods of control, with the lowest acceptance for poisoning (including poisoning their most disliked species such as the brown rat Rattus norvegicus), and emphasized the need to choose the most humane method of eradication (Bremner and Park, 2007; Rotherham and


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Lambert, 2011; Selge et al., 2011). In our study, in contrast, the respondents from all three groups declared that the choice of more or less humane methods of control does not influence their management decisions or their support for IAS control programs. Analogously to the above mentioned studies, poisoning and pesticide use was not accepted by questioned practitioners. While discussing the management of alien species both the researchers and the studied stakeholders often raise an issue of uncertainty over the actual impact of the alien species (Schlaepfer et al., 2011), principles of IAS control, as well as control methods and their efficiency (Humair et al., 2014; Kuebbing and Simberloff, 2015). Differences between respondents’ general opinions on alien species control methods were significant. The vast majority of conservation practitioners declared their approval of various methods of alien plant species control, such as destruction of seeds and seedlings, digging and cutting, but there was some skepticism about herbicides. Similarly, the use of poisons or pesticides for alien animal species control met with significant opposition from the respondents. Support was higher for killing, anaesthesia or sterilization of adult alien animals and for destruction of bird eggs than for drastic control of juveniles (e.g. killing chicks or young mammals in nests, killing pregnant females). Such differences in perception and acceptance of control methods depending on the age of the targeted animal, though apparently indicating emotion-driven sentiments, seem noteworthy, especially when shown by decision-takers. We argue that the questioned respondents did not have clearly defined attitudes towards the methods and principles of dealing with alien species, and that they probably were guided by emotions and by social or universal values. Such differences of opinion (or rather belief) were noted in a study of mental representations of animals and plants, including alien species (Fischer and van der Wal, 2007; Rotherham and Lambert, 2011; Fischer et al., 2011, 2014). Value systems or perception of values related to particular species (including alien species) vary among social groups (Rotherham and Lambert, 2011; Garcia-Llorente et al., 2011; Verbrugge et al., 2013). In some studies nativeness of species was not perceived as a highly scored value, and non-nativeness was not perceived as clear threat to local ecoor landscape systems (Fischer and van der Wal, 2007; Humair et al., 2014). One of the examples presented by Humair et al. (2014) indicates that while some nature conservation and landscape planning professionals positively value alien goldenrod species (Solidago spp.) (e.g. as a food source for pollinators or an enrichment to the landscape), the others perceive it negatively (e.g. as a competitor to the native flora or a non-matching element of the natural landscape). Yet, as shown by Kuebbing and Simberloff (2015), while asked for their motivations for alien species management, the managers reported that they were mostly driven by their personal first-hand experiences, rather than by academic journal publications, and they remained skeptical about the academic research. It seems therefore that professionals dealing with alien species management rate their personal knowledge and beliefs more than the current academic, sciencebased evidence. Bridging the knowing-doing gap in biological invasions is becoming a new motto for both scientists and practitioners (Hulme Ph, 2014). As we have shown, nature conservation professionals in Poland do not hold well-formed opinions on the principles and methods of dealing with alien species, and the current challenge is to overcome this deficit in order to enhance the effectiveness of IAS control. Although our results are geographically restricted, the problem of a mismatch between science and practice of biological invasion management seems to be a universal one. As demonstrated e.g. by Milner-Gulland et al. (2012) and Gozlan et al. (2013), scientists should not assume that just by publishing the results of their findings in scientific journals they will influence public

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opinion and IAS management policies. Selge et al. (2011) and also Sharp et al. (2011) have made it clear that increased knowledge and awareness are not a panaceum and are unlikely to change the value systems or perceptions of both the general public and the experts. Acknowledgements We are very grateful to all the participants and organizations for sharing their time, knowledge and considerable insights. Michael Jacobs line-edited the paper for submission. We thank our colleagues
ska from the Institute of Nature Conservation, Agata Pietrzyk-Kaszyn and Wiesław Król for their expertise, insight and support that greatly assisted the research. We are also grateful to the anonymous Reviewer for the discussion and valuable comments to the previous version of the manuscript. Funding was provided by the National Science Centre (project No. NN 305 3229 36). Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.envsci.2016. 01.008. References Allen, R.B., Lee, W.G., 2006. Biological invasions in New Zealand. Ecological Studies. Springer-Verlag, Berlin, pp. 1–461. Andreu, J., Vila, M., Hulme, PE, 2009. An assessment of stakeholder perceptions and management of noxious alien plants in Spain. Environ. Manag. 43, 1244–1255. Bay-Larsen, I., 2012. The premises and promises of trolls in Norwegian biodiversity preservation. on the boundaries between bureaucracy and science. Environ. Manage. 49, 942–953. Bertolino, S., Genovesi, P., 2003. Spread and attempted eradication of the grey squirrel (Sciurus carolinensis) in Italy, and consequences for the red squirrel (Sciurus vulgaris) in Eurasia. Biol. Conserv. 109, 351–358. Bonesi, L., Rushton, S.P., Macdonald, D.W., 2007. Trapping for mink control and water vole survival: identifying key criteria using a spatially explicit individual based model. Biol. Conserv. 136, 636–650. Bremner, A., Park, K., 2007. Public attitudes to the management of invasive nonnative species in Scotland. Biol. Conserv. 139, 306–314. Brown, P.M.J., Roy, H.E., Rothery, P., Roy, D.B., Ware, R.L., Majerus, M.E.N., 2008. Harmonia axyridis in Great Britain: analysis of the spread and distribution of a non-native coccinellid. BioControl 53, 55–67. Carifio, J., Perla, R.J., 2007. Ten common misunderstandings, misconceptions, persistent myths and urban legends about likert scales and likert response formats and their antidotes. J. Soc. Sci. 3 (3), 106–116. Coates, P., 2006. American Perceptions of Immigrant and Invasive Species: Strangers on the Land. University of California, Berkeley, pp. 1–266. Davenport, K., Collins, J., 2011. European Code of Conduct on Pets and Invasive Alien Species. Council of Europe T-PVS/Inf 1-–41, 1 rev. Farnworth, M.J., Watson, H., Adams, N.J., 2014. Understanding attitudes toward the control of nonnative wild and feral mammals: similarities and differences in the opinions of the general public, animal protectionists, and conservationists in New Zealand (Aotearoa). J. Appl. Anim. Welf. Sci. 17 (1), 1–17. doi:http://dx.doi. org/10.1080/10888705.2013.799414. Fischer, A., van der Wal, R., 2007. Invasive plant suppresses charismatic seabird: the construction of attitudes towards biodiversity management options. Biol. Conserv. 135, 256–267. Fischer, A., Young, J.C., 2007. Understanding mental constructs of biodiversity implications for biodiversity management and conservation. Biol. Conserv. 136, 271–282. Fischer, A., Bednar-Friedl, B., Langers, F., Dobrovodska, M., Geamana, N., Skogen, K., Dumortier, M., 2011. Universal criteria for species conservation priorities? Findings from a survey of public views across Europe. Biol. Conserv. 144, 998– 1007. Fischer, A., Selge, S., Larson, B., Van der Wal, R., 2014. The public and professionals reason similarly about the management of non-native invasive species: a quantitative investigation of the relationship between beliefs and attitudes. PLoS One 9 (8), e105495. http://dx.plos.org/10.1371/journal.pone.0105495. Fraser, K.W., 2001. Introduced wildlife in New Zealand: a survey of general public views. Landcare Res. Sci. 23, 1–45. doi:http://dx.doi.org/10.7931/DL1-LRSS-23. Garcia-Llorente, M., Martin-Lopez, B., Gonzalez, J.A., Alcorlo, P., Montes, C., 2008. Social perceptions of the impacts and benefits of invasive alien species: implications for management. Biol. Conserv. 141, 2969–2983. Garcia-Llorente, M., Martin-Lopez, B., Nunes, P.A.L.D., Gonzalez, J.A., Alcorlo, P., Montes, C., 2011. Analyzing the social factors that influence willingness to pay for invasive alien species management under two different strategies:

116


ska et al. / Environmental Science & Policy 58 (2016) 107–116 A. Olszan

eradication and prevention. Environ. Manag. doi:http://dx.doi.org/10.1007/ s00267-011-9646-z. Genovesi, P., 2005. Eradications of invasive alien species in Europe: a review. Biol. Invas. 7, 127–133. Genovesi, P., Shine, C. (2011). European strategy on invasive alien species. Nature and environment, 161. Council of Europe Publ., Strasbourg: 1–94. Gosling, L.M., Baker, S.J., 1989. The eradications of muskrats and coypus from Britain. Biol. J. Linn. Soc. 38, 39–51. Gozlan, R.E., Burnard, D., Andreou, D., Britton, J.R., 2013. Understanding the threats posed by non-native species: public vs conservation managers. PLoS One 8 (1), e53200. doi:http://dx.doi.org/10.1371/journal.pone.0053200. Heywood, V., Brunel, S. (2011). Code of conduct on horticulture and invasive alien plants. Nature and environment, 162. Council of Europe Publ., Strasbourg: 1–98. Humair, F., Edwards, P.J., Siegrist, M., Kueffer, C., 2014. Understanding misunderstandings in invasion science: why experts don’t agree on common concepts and risk assessments. NeoBiota 20, 1–30. Hulme Ph, E., 2014. Bridging the knowing–doing gap: know-who, know-what, know-why: know-how and know-when. J. Appl. Ecol. 51, 1131–1136. Kuebbing, S.E., Simberloff, D., 2015. Missing the bandwagon: nonnative species impacts still concern managers. NeoBiota 25, 73–86. Lundberg, A., 2010. Conflicts between perception and reality in the management of alien species in forest ecosystems: a Norwegian case study. Landsc. Res. 35, 319– 338. The Great Reshuffling: Human Dimensions of Invasive Alien Species. In: McNeely, J. A. (Ed.), IUCN, Gland, Switzerland and Cambridge, UK, pp. 1–242. Milner-Gulland, E.J., Barlow, J., Cadotte, M.W., Hulme Ph, E., Kerby, G., Whittingham, M.J., 2012. Ensuring applied ecology has impact. J. Appl. Ecol. 49 (1), 1–5. Minteer, B.A., Collins, J.P., 2005. Why we need an ecological ethics. Front. Ecol. Environ. 3, 332–337. Najberek, K., Solarz, W., 2011. Biological invasions in the Polish national and
ski, Z., Okarma, H., Pawłowski, J., Solarz, W. (Eds.), landscape parks. In: Głowacin Alien Species in the Fauna of Poland. I. An Overview of the Status, II. Key Issues and Summary Conclusions. Institute of Nature Conservation PAS, Krakow, pp. 624–639. Najdenowa M. (2006). Inwazje biologiczne w Polsce: znajomo
s
c problemu w
sród _ i jej stosunek do sposobów poste˛powania z gatunkami obcymi młodziezy [Biological invasions in Poland: knowledge of the problem among the highschool students and their opinions on the IAS management]. MSc thesis, Jagiellonian University and the Institute of Nature Conservation PAS, Krakow (manuscript in Polish), 1–63. Ntshotsho Ph Prozesky, H.E., Esler, K.J., Reyers, B., 2015. What drives the use of scientific evidence in decision making? The case of the South African Working for Water program. Biol. Conserv. 184, 136–144.
ska, A., Grodzin
ska-Jurczak, M., 2015. Bottom-up perspectives on Pietrzyk-Kaszyn nature conservation systems: the differences between regional and local administrations. Environ. Sci. Policy 48, 20–31. doi:http://dx.doi.org/10.1016/j. envsci.2014.12.010. Regulation (EU) No 1143/2014 of the European Parliament and of the Council of 22 October 2014 on the prevention and management of the introduction and spread of invasive alien species (http://eur-lex.europa.eu/legal-content/EN/ TXT/?uri=OJ:JOL_2014_317_R_0003). Rotherham, I.D., Lambert, R.A., 2011. Invasive and introduced plants and animals: human perceptions: attitudes and approaches to management. Earthsc. Routledge 1–352. Scalera, R., Genovesi, P., De Man, D., Klausen, B., & Dickie, L. (2012). European code of conduct on zoological gardens and aquaria and invasive alien species – code, rationale and supporting information – final version (October, 2012), T-PVS/Inf (2011) 26 revised, 1–26.

Sharp, R.L., Larson, L.R., Green, G.T., 2011. Factors influencing public preferences for invasive alien species management. Biol. Conserv. 144, 2097–2104. Schlaepfer, M.A., Sax, D.F., Oldens, J.D., 2011. The potential conservation value of non-native species. Conserv. Biol. 23 (3), 428–437. Selge, S., Fischer, A., van der Wal, R., 2011. Public and professional views on invasive non-native species—a qualitative social scientific investigation. Biol. Conserv. 144 (2011), 3089–3097. Semenchenko, V., Grabowska, J., Grabowski, M., Rizevsky, V., Pluta, M., 2011. Nonnative fish in Belarusian and Polish areas of the European central invasion corridor. Oceanol. Hydrobiol. Stud. 40 (1), 57–67. Sevä, M., Jagers, S., 2013. Inspecting environmental management from within: the role of street-level bureaucrats in environmental policy implementation. J. Environ. Manag. 128, 1060–1070. doi:http://dx.doi.org/10.1016/j. jenvman.2013.06.038. Simberloff, D., 2003. How much information on population biology is needed to manage introduced species? Conserv. Biol. 17, 83–92. Solarz, W., 2011. Small invasive alien predators in Poland annals of Warsaw University of Life Sciences-SGGW. Anim. Sci. 50 (2011), 73–81. Stokes, K.E., O’Neill, K.P., Montgomery, W.I., Dick, J.T.A., Maggi, C.A., Mcdonald, R.A., 2006. The importance of stakeholder engagement in invasive species management: a cross-jurisdictional perspective in Ireland. Biodivers. Conserv. 15, 2829–2852. Tabachnick, B.G., Fidell, L.S., 2001. Using Multivariate Statistics. Allyn and Bacon, pp. 1–986. Urgenson, L.S., Prozesky, H.E., Esler, K.J., 2013. Stakeholder perceptions of an ecosystem services approach to clearing invasive alien plants on private land. Ecol. Soc. 18 (1), 26. http://dx.doi.org/10.5751/ES-05259-180126. Vanderhoeven, S., Adriaens, T., D’hondt, B., Van Gossum, H., Vandegehuchte, M., Verreycken, H., Cigar, J., Branquart, E., 2015. A science-based approach to tackle invasive alien species in Belgium—the role of the ISEIA protocol and the Harmonia information system as decision support tools. Manag. Biol. Invasions 6 (2), 197–208. http://dx.doi.org/10.3391/mbi.2015.6.2.10. Veitch, C.R., Clout, M.N., 2001. Human dimensions in the management of invasive species in New Zealand. In: McNeely, J.A. (Ed.), The Great Reshuffling: Human Dimensions of Invasive Alien Species. IUCN, Gland, Switzerland and Cambridge, UK, pp. 63–71. Verbrugge, L.N.H., Van den Born, R.J.G., Lenders, H.J.R., 2013. Exploring public perception of non-native species from a visions of nature perspective. Environ. Manag. 52, 1562–1573. doi:http://dx.doi.org/10.1007/s00267-013-0170-1. Young, A., Larson, B., 2011. Clarifying debates in invasion biology: a survey of invasion biologists. Environ. Res. 111, 893–898. doi:http://dx.doi.org/10.1016/j. envres.2011.06.006. Zavaleta, E.S., Hobbs, R.J., Mooney, H.A., 2001. Viewing invasive species removal in a whole-ecosystem context. Tree 16 (8), 454–459.

Websites ALARM (Assessing Large Scale Risk for biodiversity with tested Methods, http:// www.alarmproject.net/alarm). Institute of Nature Conservation PAS in Krakow “Alien Species in Poland” www.iop. krakow.pl/ias. IUCN Council (2000) Guidelines for the prevention of biodiversity loss caused by alien invasive species. Prepared by the IUCN/SSC Invasive Species Specialist Group (ISSG) and approved by the 51st Meeting of the IUCN Council, Gland, Switzerland (http://www.issg.org/pdf/guidelines_iucn.pdf).