Which protected areas should be prioritized for prevention and early detection of biological invasions? A new methodological approach

Protected areas are key to global biodiversity conservation efforts. Yet, most protected areas globally face threats of biological invasions either by invasive non-native species established within the protected area or by the imminent establishment of invasive non-native species established in the surrounding landscapes. In face of growing biological invasions, protected area managers must be able to set prevention and control priorities for invasive non-native species management. In this study, we developed a new methodological approach to identify which protected areas should be prioritized for prevention and early detection and which should be prioritized for control of biological invasions. Our methodological approach analyzes the occurrence of invasive species within and around the protected areas and weights the influence of multiple existing pathways to calculate the probability of introduction of invasive species and colonization pressure for each protected area. We evaluated our priority setting model in 280 terrestrial and 42 marine protected areas in Brazil. For the terrestrial protected areas, 84 were classified as priority for prevention and early detection and 124 were classified as priority for control of biological invasions. For the marine protected areas, 25 were classified as priority for prevention and early detection and seven were classified as priority for control of biological invasions. Human population density and percentage of pasture cover surrounding the protected area were the most important factors for priority setting in terrestrial protected areas whereas number of aquiculture activities, density of waterways, distance to ports, distance to oil platforms, and distance from sinking points were the most important factors for priority setting in marine protected areas. In conclusion, the framework presented here provides an objective methodology for managers and stakeholders to decide where to invest their limited resources available for management of biological invasions in protected areas.