Invasive alien species are among the greatest threats to biodiversity and may easily spread from one country to another once established, as countries differ in their capacity to prevent invasions, biosecurity protocols and implementation of international standards.
This study explores the biosecurity implications in six scenarios of invasions in contiguous countries with varying levels of impact and spread. Based on the list of the world's worst invaders in the Global Invasive Species Database, the study analysed 86 species assessing introduction and invasion threats, modelling potential distributions based on GBIF-mediated occurrences to inform invasion scenarios.
Predicting more than 2,500 future invasions, the study finds that most invaders–around 60 per cent—are likely to establish in one country but not spread to neighbouring countries. Many of these invasions, however, are unlikely to be prevented due to the low response capacity of the countries in which they are predicted to occur.
More than a third of the predicted invasions are likely to spread beyond the country of introduction, with the majority of invasions causing impact in more than one country. With low preventive/responsive capacity in many countries, these scenarios call for regional cooperation around biosecurity to prevent harmful effects of future biological invasions.