WatchListR: a tool for developing watch-lists of invasive species to inform biosecurity decision-making

The Global Biodiversity Framework calls for member countries to reduce the rate of introduction of known or potential invasive alien species by at least 50 percent by 2030. An essential tool that will assist countries in achieving this ambitious target is a list of known or potential invasive alien species that are absent from their territories but might enter along a variety of pathways (‘watch-list’ hereafter). Generating watch-lists requires consideration of curated information on a large number of species. The growing volume of distribution data and the improved understanding of historical species introductions and invasions have created a significant data overload for countries compiling watch-lists. We have developed a computational workflow to automate part of this process, enabling countries to draw up these lists quickly and cost-effectively. The WatchListR tool requires reliable and accurate information on species present in the country (indigenous and introduced, as well as economically important). As information on which species are present is sometimes not readily available, local experts should ideally review and verify the watch-lists developed by WatchListR . As a case study, we used WatchListR to develop a list of species prohibited for importation into the Republic of Mauritius. We explore the development of WatchListR , describe the processes used, consider the efficacy of the tool, highlight planned future advancements, and suggest how countries can support the tool’s development through the use and creation of expert-validated watch-lists.