DRAFT, 10th June 2003
A New Agenda for Biosecurity, September 2005
Contents
Executive Summary 8
Chapter 1 – Study Background and Objectives 15
1.1 Government policy on non-native species risks 17
1.2 The nature and scale of non-native species risk 18
1.3 Objectives of the study 19
Chapter 2 – an Ecological Model for Non-native Species Introductions 21
2.1 Conceptual model 21
2.1.2 Formalisation 22
2.1.3 Behaviour and validity of the biological spread model 24
2.2 Biological patterns of non-native species introduction 26
2.2.1 Terrestrial invertebrates 26
2.2.2 Plant diseases 31
2.2.3 Vertebrates 34
2.2.4 Animal diseases 36
2.2.5 Terrestrial plants 39
2.2.6 Aquatic species 43
2.3 Conclusions from cross-taxon review 48
2.3.1 Origin of non-native species risks 49
2.3.2 Nature and impact of non-native species 50
Chapter 3 – an Economic Model for Non-Native Species Introduction 52
3.1 Formalisation 52
3.1.1 Graphical representation 54
3.2 Stochastic simulation 59
3.3 Parameterisation 61
3.4 Dealing with non-market (e.g. environmental) factors 62
Chapter 4 – Economic Case Studies 63
4.1 Colorado Beetle 64
4.1.2 Control case 65
4.1.3 Results 67
4.1.4 Conclusion 70
4.2 Wild boar 70
4.2.1 Affected industries in the United Kingdom 71
4.2.2 Control case 71
4.2.3 Results 73
4.2.4 Conclusion 76
4.3 Potato Ring Rot 76
4.3.1 Affected industries in the United Kingdom 77
4.3.2 Control case 77
4.3.3 Results 79
4.3.4 Conclusion 82
4.4 Newcastle Disease 82
4.4.1 Affected industries in the United Kingdom 83
4.4.2 Control case 83
4.4.3 Results 86
4.4.4 Conclusions 89
4.5 Gyrodactylus salaris 89
4.5.1 Affected aquaculture industries in the United Kingdom 90
4.5.2 Control case 90
4.5.3 Results 93
4.5.4 Conclusion 96
4.6 Creeping Thistle 96
4.6.1 Affected industries in the United Kingdom 97
4.6.2 Control case 97
4.6.3 Results 99
4.6.4 Conclusions 102
Chapter 5 – Patterns of Impact of Non-native Species 103
5.1 Comparing impact estimates between species 104
5.2 Comparing patterns of impact over time 105
5.2.1 Constant expected impact increments over time 105
5.2.2 Diminishing expected impact increments over time 107
5.2.3 Increasing expected impact increments over time 108
5.3 Cross-over effects and variability 110
Chapter 6 – Horizon Scanning and Impact Levels 113
6.1 Climate change 115
6.2 Trade and markets 118
6.2.1 A conceptual model for trade and introduction 118
6.2.2 The effect of trade on UK agriculture and land use 122
6.3 Social issues 124
6.3.1 What is a non-native species? 125
6.3.2 New species and societal change 126
6.3.3 Which way will the future go? 127
6.4 Conclusions 128
6.5 A Quantitative Approach to Horizon Scanning 129
6.5.1 Description 130
6.5.2 Affected Industries in the United Kingdom 130
6.6.3 Control Case 131
6.5.4 A Trade Change Scenario 139
6.5.5 A CAP Reform Scenario 141
6.5.6 Conclusion 143
Chapter 7 – Prevention and Eradication of Non-native Species Threats 144
7.1 Prevention and eradication strategies – an overview 145
7.2 Eradication 145
7.2.1 Eradication, net benefit maximisation and EDcrit 148
7.2.2 Multiple net benefit maximisation options 150
7.3 Prevention 151
7.4 Evaluating prevention vs. eradication policy options 153
7.5 Multiple technological options 156
7.6 Technical change and how to value it 157
Chapter 8 – Conclusions 160
8.1 Are biosecurity risks increasing? 160
8.2 Can we take a general approach to predicting the economic impact of future introductions? 161
8.3 Are some kinds of risk consistently more important than others? 163
8.4 Are future societal trends going to change risk substantially? 163
8.5 Can we prioritise investment in control methods? 164
8.6 How can policy makers use this study? 165
References 167
Appendix 1: Finite Markov Chains 175
Appendix 2: Non-indigenous species in the UK: exploring their meanings in human and social terms 176
Acknowledgements 176
Executive summary 176
1.0 Background to the Research 177
2.0 The historical and social context 177
3.0 Conceptions of Non indigenous species amongst different actors 179
3.1 Mapping out different discourses 179
3.2 What do the different discourses tell us? 181
4.0 Issues of Definition: ‘Non-indigenous’, ‘Non-Native’, ‘Alien’, and ‘Invasive’ Species 183
4.1 Native/non-native definitions 184
4.2 Invasiveness 185
4.3 Alienness 186
4.4 Definitions: a need for clarity? 187
5.0 Public Perceptions 188
5.1 The supposed problem of ‘lay ignorance’ 189
5.2 Perceptions of non-indigenous species in the UK 190
5.3 Public Engagement 191
5.4 Thinking about the future 192
6.0 Conclusions and Recommendations 195
Bibliography 196
Figures
Figure 1: The annual number of newspaper articles on non-native species problems from UK broadsheets presented as (a) total numbers and (b) numbers per 10,000 science/environment articles. Analysis used the Factiva database, searching for keywords combining “non-native, alien, invasive or exotic” with different plant/animal groups. Newspapers: Guardian, Times, Independent, Independent on Sunday, Financial Times, Observer, Sunday Times. 16
Figure 2.1: A conceptual model of non-native species invasion. The main processes are identified: 1) Arrival and establishment; 2) Local population growth and spread; and 3) Satellite generation, and the biological/geographical (red) and anthropocentric (blue) controllers. 22
Figure 2.2: The influence of intrinsic growth rate (r) and satellite generation rate (m) on total area occupied after 30 years. Diffusion coefficient fixed at 40 ha/yr. 24
Figure 2.3: First recordings of non-native pestiferous arthropod species in Europe (data derived from Smith 1997). Fitted line represents the best fit poisson model (log [species per decade] = 0.04yr – 75.6; P = 0.004; r2 = 0.63). 28
Figure 2.4: First recordings of non-native plant diseases in Europe (including bacteria, fungi and nematodes; data derived from Smith 1997). Fitted line represents the best fit linear regression model (y=-52.7 + 0.028x, P = 0.006, r2 =0.54). 32
Figure 2.5: Decade of first introduction (a) and first record in the wild (b), of neophyte taxa in the UK and Ireland (compiled from Preston et al., 2002). Lines are fit by local non-parametric regression. 41
Figure 2.6: Frequency histogram of the lag between year of first import and year of first record in the wild for established (naturalised) plant taxa in the UK and Ireland (compiled from Preston et al., 2002). 41
Figure 2.7: Arrival of non-native aquatic species to the UK as collated in the FAO DIAS database. 46
Figure 2.8: Rate of arrival of non-native species to the Baltic Sea due to deliberate stocking, species associated with deliberate stocking, and accidental introductions due to shipping. 46
Figure 2.9: Rate of arrival of species to the Baltic Sea according to taxon. 47
Figure 2.10: Median radial spread rates of the six groups included in this study. Bars represent maxima and minima. 51
Figure 3.1: The production function with and without a harmful non-native species in the system 55
Figure 3.2: The economic impact of a harmful non-native species – imported goods 57
Figure 3.3: The economic impact of a harmful non-native species – exported goods 58
Figure 4.1: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Colorado Beetle 67
Figure 4.2: Area/Time and variability – Colorado Beetle 67
Figure 4.3: Expected Invasion Impact (EI)/Time – Colorado Beetle 68
Figure 4.4: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Wild Boar 73
Figure 4.5: Area/Time and variability – Wild Boar 73
Figure 4.6: Expected Invasion Impact (EI)/Time – Wild Boar 74
Figure 4.7: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Potato Ring Rot 79
Figure 4.8: Area/Time and variability – Potato Ring Rot 79
Figure 4.9: Expected Invasion Impact (EI)/Time – Potato Ring Rot 80
Figure 4.10: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Newcastle Disease 86
Figure 4.11: Incidence/Time and variability – Newcastle Disease 86
Figure 4.12: Expected Invasion Impact (EI)/Time – Newcastle Disease 87
Figure 4.13: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Gyrodactylus salaris 93
Figure 4.14: Incidence/Time – Gyrodactylus salaris 93
Figure 4.15: Expected Invasion Impact (EI)/Time – Gyrodactylus salaris 94
Figure 4.16: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years – Creeping Thistle 99
Figure 4.17: Area/Time – Creeping Thistle 100
Figure 4.18: Expected Invasion Impact (EI)/Time – Creeping Thistle 100
Figure 5.1: Constant expected impact increments over time 106
Figure 5.2: Decreasing expected impact increments over time 107
Figure 5.3: Increasing expected impact increments over time 109
Figure 5.4: Cross-over effects 111
Figure 5.5: Cross over effects with variance included. 112
Figure 6.1: A species pool model in which the pool of potential non-native species is defined by the action of abiotic, biotic, trade and transport constraints 119
Figure 6.2: Patterns of first wild record of naturalised non-native plant species in the UK and Ireland. Curves are fitted non-parametric cubic B-splines (3 d.f.). 121
Figure 6.3: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years for the control case – Foot & Mouth Disease 136
Figure 6.4: Incidence/Time and variability – Foot & Mouth Disease 136
Figure 6.5: Expected Invasion Impact (EI)/Time – Foot & Mouth Disease 137
Figure 6.6: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years in the trade change scenario – Foot & Mouth Disease 140
Figure 6.7: Cumulative distribution of the critical level of Expected Damage (EDcrit) differential between the control case and the trade change scenario over 20 years – Foot & Mouth Disease 140
Figure 6.8: Cumulative distribution of the critical level of Expected Damage (EDcrit) over 20 years in the CAP reform scenario – Foot & Mouth Disease 142
Figure 6.9: Cumulative distribution of the critical level of Expected Damage (EDcrit) differential between the control case and the CAP reform scenario over 20 years – Foot & Mouth Disease 142
Figure 7.1: Benefits of management effort – e.g. an export-limiting disease 147
Figure 7.2: Eradication of an incursion 148
Figure 7.3: Eradication or strategic management? 150
Figure 7.4: Pre-invasion biosecurity measures 151
Figure 7.5: No solution through eradication 152
Figure 7.6: Total Expected Benefits of a hypothetical prevention technology for Colorado Beetle 153
Figure 7.7: Expected Net benefit stream for prevention technology 154
Figure 7.8: Distribution of the present value of net benefits for the prevention option. 155
Figure 7.9: Alternative management technologies 157
Tables
Table 2.1: Non-native species used as case studies for model design 21
Table 2.2: Parameter values found in the literature for the spread of non-native terrestrial invertebrate species. 29
Table 2.3: Parameter values found in the literature for the spread of plant diseases. Here r refers to the intrinsic rate of increase of the infected population of the host species. Since these are agricultural host species, this rate of increase of infection relates readily to spatial extent of infection. 33
Table 2.4: Parameter values found in the literature for the spread of non-native terrestrial vertebrate species 35
Table 2.5: Parameter values found in the literature for the spread of animal diseases 39
Table 2.6: Parameter values obtained form the literature relating to the spread non-native plant species. † - data concern post-glacial spread of species as estimated from pollen analyses 42
Table 2.7: Data from Grosholz (1996) on the rate of spread of ten marine species. 48
Table 3.1: Semi-Quantifiable Risk Categorisation Methodology (AFFA, 2001) 62
Table 4.1: Industries affected by Colorado Beetle 65
Table 4.2: Parameterisation – Control Case (Colorado Beetle) 66
Table 4.3: Sensitivity Analysis – Colorado Beetle 69
Table 4.4: Industries affected by Wild Boar 71
Table 4.5: Parameterisation – Control Case (Wild Boar) 72
Table 4.6: Sensitivity Analysis – Wild Boar 75
Table 4.7: Industries affected by Potato Ring Rot 77
Table 4.8: Parameterisation – Control Case (Potato Ring Rot) 78
Table 4.9: Sensitivity Analysis – Potato Ring Rot 81
Table 4.10: Industries affected by Newcastle Disease 83
Table 4.11: Parameterisation – Control Case (Newcastle Disease) 85
Table 4.12: Sensitivity Analysis – Newcastle Disease 88
Table 4.13: Industries affected by Gyrodactylus salaris 90
Table 4.14: Parameterisation – Control Case (Gyrodactylus salaris) 92
Table 4.15: Sensitivity Analysis – Gyrodactylus salaris 95
Table 4.16: Industries affected by Creeping Thistle 97
Table 4.17: Parameterisation – Control Case (Creeping Thistle) 98
Table 4.18: Sensitivity Analysis – Creeping Thistle 101
Table 5.1: Estimated impacts on 20 year time horizons for different species (from case studies). 104
Table 6.1: The relationship between model processes, their drivers and response 113
Table 6.2: Principal predictions of the UKCIP02 (Hulme et al. 2002), and their hypothesised influence on model parameters. Confidence level: High, medium or low, is a qualitative assessment of the reliability of these predictions given by UKCIP. 116
Table 6.3: Survey of the ISI publications database with search terms: climate change and (species invasions or species range). The entries don’t represent a review of literature related to the effect of climate change on life-history parameters of species in general, but in particular those referring to invasive species and changes in geographical range 117
Table 6.4: Industries affected by Foot & Mouth Disease 130
Table 6.5: British Beef Exports (Tonnes) 132
Table 6.6: Parameterisation – Control Case 133
Table 6.7: Sensitivity Analysis – Foot & Mouth Disease 138
Table 6.8: Parameterisation – Climate Change Scenario (Foot & Mouth Disease). The arrow indicates parameters which are increased in the scenario. 139
Table 6.9: Parameterisation – Trade Liberalisation Scenario (FMD) 141
Table 8.1: Impact Table 162
Executive Summary
Introduction
The recent Foot and Mouth Disease outbreak, the spread of rhododendron in national parks, the appearance of Sudden Oak Death (Phytophthora ramorum) fungus on native vegetation, the appearance of new leaf miner species on glasshouse crops: all of these demonstrate the invasive non-native species problems to which Defra responds. These problems are dealt with by different parts of Defra, reflecting the ecology, economics and historical perspectives of the animal health, plant health and conservation services and their understanding of public expectations.