Humans have introduced plants and animals into the British Isles throughout its history. Whilst the overwhelming majority of introduced species present little threat to our native wildlife, some can have a detrimental effect on our flora and fauna by outcompeting native species, causing disease or acting as predators. The most harmful invasive species have been listed on Schedule 9 of the Wildlife and Countryside Act (1981), making it an offence to allow them to escape or spread into the wild. This includes plants such as Japanese knotweed and Himalayan balsam, and animals such as American mink and signal crayfish.
A site visit can be undertaken to check for the presence of invasive species on a development site. Should an invasive plant species be identified, an appropriate removal and eradication technique will need to be implemented if the species is likely to be disturbed by development. This may include the production of a method statement that outlines steps that can be taken to ensure that invasive species do not spread.
Himalayan balsam (foreground) and Japanese knotweed (background) are both listed on Schedule 9 of the Wildlife and Countryside Act (1981).