Biosecurity under uncertainty: the influence of information availability and quality on expert decision-making for risk outcomes Alisha A Dahlstrom, B.Sc. Aquatic Biology, B. Sc. Environmental Studies Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy University of Tasmania. Launceston, Tasmania March 2012 DECLARATION OF ORIGINALITY The work presented in this thesis is, to the best of my knowledge, original and my own work, except where referenced in the text. I hereby declare that I have not submitted this material, in any form, to this or another University, for the award of a degree. -------------------------- Date AUTHORITY OF ACCESS This thesis may be made available for loan and limited copying in accordance with the Copyright Act 1968. -------------------------- Alisha Dahlstrom Date STATEMENT REGARDING PUBLISHED WORK CONTAINED IN THESIS The publishers of the papers comprising Chapters 2-5 hold the copyright for that content, and access to the material should be sought from the respective journals. The unpublished content of the thesis may be made available for loan and limited copying in accordance with the Copyright Act 1968. STATEMENT OF ETHICAL CONDUCT The research associated with this thesis abides by the international and Australian codes on human and animal experimentation, the guidelines by the Australian Government's Office of the Gene Technology Regulator and the rulings of the Safety, Ethics and Institutional Biosafety Committees of the University. i STATEMENT OF CO-AUTHORSHIP The following people and institutions contributed to the publication of the work undertaken as part of this thesis: Chapter 2: Dahlstrom, A., C. L. Hewitt, and M. L. Campbell. 2011. A review of international, regional and national biosecurity risk assessment frameworks. Marine Policy 35:208-217. Dahlstrom, A (60%), Hewitt, CL (20%), Campbell, ML (20%) Chapter 3: Dahlstrom, A., C. L. Hewitt, and M. L. Campbell. 2011. Mitigating uncertainty using alternative information sources and expert judgment in aquatic nonindigenous species consequence assessment. Aquatic Invasions (in review). Dahlstrom, A (60%), Hewitt, CL (20%), Campbell, ML (20%) Chapter 4: Dahlstrom, A., C. L. Hewitt, and M. L. Campbell. 2011. The role of uncertainty and subjective influences on consequence assessment by aquatic biosecurity experts. Biological Conservation (in review). Dahlstrom, A (60%), Hewitt, CL (20%), Campbell, ML (20%) CL Hewitt and ML Campbell both contributed to the idea, its formalization and development, and assisted with refinement and presentation. Chapter 5: Dahlstrom, A. and C. L. Hewitt. 2011. Evidence of impact: low statistical power leads to false certainty of no impact for nonindigenous species. Nature (in prep). Dahlstrom, A (80%), Hewitt, CL (20%) CL Hewitt contributed to the idea, its formalization and development, and assisted with refinement and presentation. ii ABSTRACT Alongside climate change and habitat loss, aquatic nonindigenous species (ANS) introductions comprise a large and increasing contribution of the anthropogenic threat to environmental, economic, sociocultural and human health values worldwide. Biosecurity agencies aim to prevent and manage introductions using various tools, including risk assessment. Risk assessment can prioritize threats, but is frequently compromised by uncertainty, often due to information availability, quality and interpretation. Many risk assessment processes lack consistent and transparent treatment of uncertainty, particularly when biosecurity objectives warrant a precautionary approach. This thesis aims to identify methods for managing uncertainty via an initial review of 14 existing national, regional and international biosecurity instruments. Results from this review found over half of the instruments explicitly included or mentioned precaution, and many instruments acknowledged the potential influence of subjective risk perceptions. Based on these outcomes, this thesis aims to: determine sources of uncertainty; understand the cognitive process of estimating consequence, and therefore risk under uncertainty; and provide transparent methods to reduce uncertainty that allow for precaution, using input from ANS experts in scientific and management fields. Finally, this thesis aims to examine how the frequentist statistical focus on low acceptable rates of Type I errors, most frequently applied in ANS impact research, influences findings of significant impact and the implications for management decisions. Results of this thesis indicate that the scarcity of ANS impact information constitutes a primary source of uncertainty. When faced with knowledge gaps and other forms of uncertainty, experts tended to assume and assign lower consequence via a ‘hindsight approach’ (assume no impact without sufficient information), which stands opposite to precaution. To mitigate the effects of uncertainty, experts supported the use of alternative information sources, including non-empirical evidence. In practice, the provision of information and group discussion generally increased the consequence estimate, thus suggesting methods that allow functional and, if desired, precautionary consequence assessments despite high uncertainty. In situations of expected ‘low’ certainty, when information is available, my research indicated that an extremely high proportion of statistical analyses of impact had insufficient power to detect an impact, leading to ‘false certainty’ of no impact. This bias toward ‘missing’ impacts, again opposite to precaution, may further prevent appropriate management action. iv The thesis concludes with a proposed framework that provides guidance for biosecurity-related research and management using an acceptable level of risk. It provides a transparent process and usable risk outcomes that: (1) integrate scientific process and management objectives; (2) are accountable for and unimpeded by uncertainty; (3) consider the assumptions used by the experts making the assessment; (4) can be adapted according to varying strengths of precaution desired by management; (5) follows World Trade Organization Sanitary and Phytosanitary (SPS) Agreement mandates; and (6) are feasible given time and budget constraints. v ACKNOWLEDGEMENTS I wish to sincerely thank my supervisor Prof. Chad Hewitt and co-supervisor Prof. Marnie Campbell. I began my PhD with a project that promptly changed within a few weeks of my arrival. They provided me with the freedom to develop a new project, yet provided patient and invaluable guidance along the way that allowed me to arrive at its successful conclusion with some novel insights and appreciation for some of the social underpinnings of science. Their time and effort as mentors and, eventually, colleagues is most gratefully appreciated. I am grateful to Dr. Greg Ruiz for providing me space at the Smithsonian Environmental Research Center (SERC) and also valuable input into my project during the first year of its development. A. Whitman Miller and Paul Fofonoff, also at SERC, provided useful feedback and collaboration. I am grateful to the Australian Maritime College, a specialist institute of the University of Tasmania, for financial support via the John Bicknell Research Scholarship, which permitted my study in Australia. I also acknowledge the other sources of funding including the Australian Geographic Society and the University of Tasmania Graduate Research Candidate Conference Fund Scheme. I also thank the Human Research Ethics Committee (Tasmania) Network for ethics approval. I wish to thank Jan Daniels and Mandy Norton for their kind assistance with all things administrative. I also wish to thank those individuals within each conference that facilitated organization of each workshop: Robyn Draheim (MBIC), Narelle Hall (AMSA), Lisa Carmody and Elizabeth Muckle-Jeffs (ICAIS) and Sonia Gorgula (NIMPCG). I owe the outcomes of Chapters 3 and 4 to all the participants who generously gave their time participating in the surveys and workshops, tirelessly putting up blue and red dots. To my parents, my endless thanks. It is only as I grow older that I realize the sacrifices you made as individuals and as a couple to get me to where I am. I am sorry I ended up so far away, but thank you for letting me go. To my brothers, your humour and camaraderie have a special place in my heart – I look forward to larger doses in the future. To my friends back in ‘merica, thank you for not forgetting me, down here at the end of the world, and always welcoming me back with big smiles and open arms when I manage a whirlwind visit (and a special thanks to those who ventured down here for a visit, long or short!) To my Tassie friends, thank you for welcoming me to the island and taming my obnoxious accent; you made these three years a joy. And to Tassie – I fell in love with your beautiful wildness like few other places I’ve been; they gave me peace and comfort when nothing else could. And to my partner in all things, Ben (GGB), thank you for your unfailing patience, love and ability to remind me what matters most in life. vi TABLE OF CONTENTS Declaration of Originality .............................................................................................................. i Authority of Access ....................................................................................................................... i Statement regarding published work contained in thesis ............................................................... i Statement of Ethical