An ‘Invasive Species’ is a non-native plant or animal, which adversely affects the habitat it invades, ecologically or economically. Great movements of goods between countries, has facilitated the transport of plants and animals, across geographical barriers (oceans and mountains), allowing them to colonise new areas of the world.
It is becoming increasingly apparent that invasive species are a serious threat to the world’s biodiversity. The effects of invasions have proven to be particularly acute on small or isolated islands, where resident plants and animals have often evolved without the presence of the competitive pressures of their continental cousins. Therefore, they have inadequate defences to contend with new arrivals. Many islands have suffered heavily from the wave of invasion, culminating in extinctions. For this reason, we must be extra vigilant concerning invasive species, in order to protect the natural treasures of our island home.
Shifting baselines are a key issue when considering invasive species. This term relates to two main scenarios. The first is a tendency to overlook slow, steady deterioration of ecosystems because they are less obvious than large scale alterations. The second is for species which have been present for a number of generations to be perceived as native or to be mistaken for native species. The shifting baseline undermines environmental awareness and erodes a concept of cultural heritage, promoting a misplaced attachment and valuing of the exotic, the immediate and the commonplace, above the natural, the traditional and the rare.