- The number of newly emerging alien species continues to rise, posing a significant challenge to biosecurity interventions worldwide, according to a study. Alien species are those that do not belong to a region and introduced intentionally or accidentally by humans.
- Up to 16 per cent of all species on Earth may be alien species and if they invade new regions, impacts will be difficult to predict. Approaches to tackle the growing issue largely rely on knowledge of species’ invasion history elsewhere, giving new previously unrecorded alien species a higher chance of slipping through border controls and eluding early response management.
- For plants, mammals, and fishes, the proportion of newly emerging alien species has remained constant during the last 150 years but the total number of alien species has increased.
- Insects, molluscs and other invertebrates have the highest proportion of emerging alien species.
- Birds are the only group exempt from the trend, showing the lowest proportions of emerging alien species, with a distinct decline noted recently.