Optimal detection and control strategies for invasive species management

The increasing economic and environmental losses caused by non-native invasive species amplify the value of identifying and implementing optimal management options to prevent, detect, and control invasive species. Previous literature has focused largely on preventing introductions of invasive species and post-detection control activities; few have addressed the role of detection. By increasing resources to detect invasive species, managers may increase their chances of finding a species at a smaller population level, lessening the extent of damages and making subsequent control potentially less expensive and more effective. However, detecting new invasive species is difficult and uncertain; many factors reduce the likelihood of successful detection, such as low population densities which are prevalent in invasive species management. This paper presents a model that captures the stochastic and dynamic aspects of this trade-off by incorporating a detection stage in which the agency managers choose search effort prior to the post-detection control stage. The analysis of the model illustrates that the optimal detection strategy depends primarily on the 'detectability', or ease of detection, and the biological relationships of each distinct species.