PARENT SESSION
Symposium 13: Prediction and prioritization of future invasive species
Organized by: RN Mack and M Lonsdale
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 517 A, Level 5, Palais des congrès de Montréal
Using decision theory tools for the management of invasive species.
Regan, Tracey*,1, Possingham, Hugh1, McCarthy, Michael2, Panetta, Dane3, 1 The Ecology Centre, St. Lucia, Queensland, Australia2 Australian Research Centre for Urban Ecology, Parkville, Victoria, Australia3 Alan Fletcher Research Station, Sherwood, Queensland, Australia
ABSTRACT- Invasive species eradication programs are deliberate management that leads to the extinction of an invasive species from a particular area. Verifying whether all individuals have been extirpated from an area and eradication has been achieved is extremely difficult because some species will be difficult to detect because they are behaviorally or morphologically cryptic, they inhabit terrain that is difficult to survey or are hard to find because abundances are low. Currently few practical guidelines exist for verifying the success of an eradication program. Instead eradication is often declared either on an ad-hoc basis or on some intuition about persistence. We develop a decision support tool for when to stop monitoring and declare eradication given that an invasive species has not been seen for some time. We couch this question within a decision theory framework, a discipline that allows managers to optimize the costs and benefits of their actions. The model determines how many years of absences are required to minimize the net expected cost. The optimal stopping time depends on how easily the species is detected when abundances are small, the probability of persistence, and the trade off between the costs of continued monitoring and the cost if the species escapes and causes damage. The model is developed generally for invasive plants but can easily be adapted to any invasive species.
Key words: invasive species, decision theory, eradication