Programme of Measures - Invasive Alien Species - 2015

Animals and plants that have been introduced to a place where they do not naturally occur are known as alien species. Many of these do not cause problems, but some can become invasive as they upset the balance of the ecosystem as they may be bigger, faster growing or more aggressive than the native species, and some may carry diseases such as Crayfish plague. They may also have fewer natural predators to control numbers. The native species are often unable to compete and the invasive species take over causing serious problems for biodiversity and the economy.