Closing the gaps: workflows to improve alien species lists and streamline the process from detection to action

Up-to-date, interoperable alien species lists are required to estimate the status and trends of biological invasions, to monitor and report on progress towards Target 6 of the Kunming-Montreal Global Biodiversity Framework, and to inform management. In South Africa, numerous alien species lists exist, but they are not interoperable, and the taxon names are often out-of-date and contain errors. New incursions into South Africa are also detected in several ways, including through DNA barcoding projects, but there are currently no workflows in place to ensure that these records are incorporated into alien species lists and are acted upon. In response to these challenges, we developed two, linked workflows. An open, automated workflow that is relevant to the South African context was developed to standardise the taxon names in South African alien species lists. Tested using three lists of alien taxa (error rates: 14-20%), the workflow can automatically standardise hundreds of taxon names in minutes, leaving few (0.3-13.8%) that require manual work. A simple workflow, which incorporates the taxon name standardisation process, was developed to ensure molecular observations are evaluated and flagged for further action and inclusion in alien species lists. Using the workflow, we compared the 10 084 records from the ‘Barcode of Life Data System’ (BOLD) for South Africa to three datasets: a watch list of species of concern (400 species); a list of high-risk agricultural pests detected at the border, but not yet established (218 species); and the Botanical Database of Southern Africa (68 153 records), which includes alien plant species found outside of cultivation. By executing the workflow, we identified eight species that have been detected during molecular studies, but that are not yet recognised or managed as alien species in South Africa. Taken together these workflows improve alien species lists and keep them up-to-date, and flag potential biosecurity risks for management. Although tested using South Africa as a case study, the workflows are generalisable and can be adapted for use in other regions facing similar challenges.