Global biodiversity is in decline and one of the major threats is the spreading of non-native species. Non-native species (NNS) are animals and plants that have been moved out of their natural area by human action, whether it is intentional or not. The risk of spreading non-native species is that they become invasive, displacing native animals and plants and causing damage to environments and local economies. Biosecurity measures are therefore essential to minimise the impacts of invasive non-native species (INNS) and to prevent the spread of others.
Water is an excellent transport method for the dispersal of non-native animals and plants, making rivers, lochs and their banksides particularly vulnerable to INNS. The River Tweed is home to several INNS already and is at risk from the spread of several others. As a means of controlling the spread and effects of INNS in the Tweed catchment, the Tweed Foundation, alongside the Tweed Forum and Rivers and Fisheries Trusts of Scotland, developed the Tweed Catchment Biosecurity Plan. The Plan targets three main areas:
Find out more about the Tweed Catchment Biosecurity Plan here.
Several NNS have been highlighted in the Plan as being "high impact species", either because they already exist within the Tweed catchment, because of the risk they would pose to the local biodiversity and economy if introduced, or because of an increased risk of introduction.
Several of these non native species can be seen below, some of which are already in the catchment while others pose a high risk if introduced.