Human activity, both accidental and intentional, has led to the spread of thousands of species beyond their natural range. Many of these species are not only able to adapt to their new environment, they thrive and quickly become established by outcompeting native flora and fauna for food and shelter.

Scottish Invasive Species Initiative work, with the help of volunteers and contractors, to control invasive non-native species such as Himalayan balsam, Japanese knotweed, Giant hogweed and American mink, throughout the River South Esk catchment, and across the wider Angus area.