More and more plants and animals are turning up where they don’t belong. The global system of transportation is carrying them around the world. Alarmingly alien species have the potential to cause damage to the health and wellbeing of our communities and need to be kept in check. At the end of World War II, American soldiers in the Pacific used wooden crates to ship equipment back to the United States. Little did they know that they were also transporting an aggressive breed of termite. They might be small but in large numbers they are destructive, bringing down the timber homes that dominate New Orleans.
In Uganda it took only a few years for water hyacinth, not native to the area, to rapidly spread around Lake Victoria, choking the banks. Diseases such as malaria and dysentery have been on the rise, and the prevalence of the plant has made it harder for fishermen to make a living. Can a small insect, the weevil, bring the water hyacinth under control? In the forests of Hawaii, a plant introduced in the 1960s, has become a new source of erosion. The invasive plant with its destabilising root system has caused an increasing number of landslides. Not only devastating to species in the forests, soils being dumped in the oceans are also damaging sea-life.