Invasive alien species – one of the greatest threats to biodiversity, and to the ecological and economic well-being of society and the planet.

Today – 22nd May the International Day for Biological Diversity. The theme for this year is:

“Invasive alien species – one of the greatest threats to biodiversity, and to the ecological and economic well-being of society and the planet”

1. What are invasive species?

They are plants and animals, which, after being introduced into an island or area, establish themselves and spread naturally in the ecosystem. Invasive organisms are known for their negative impact on the environment they have established themselves in. Native plants and animals have been noticed to diminish in numbers from such areas resulting in the overall loss of biodiversity. The occurrence of invasive species in an area is also indicative of human activities (that have negative impacts) in and around the surrounding area.
Biological invasions are a natural process, whereby a species arrives into a location in which it did not historically exist. (Elton, 1958; Vermaij, 1996; Crooks, 2002). Not all introduced species become established in their environment, but certain percentages do, and become abundant at the expense of the native species. (Primack, 1998). Extinctions and native faunal population declines caused by introduced species are greatest on islands (Simberloff, 1995).

Some examples of invasive alien species that have threatened Fiji’s unique biodiversity are:

  1. Spathodea campanulata – the African tulip tree. Locally known as Vuni pasiu;
  2. Bufo marinus – cane toad. Locally known as Botonivavalagi or botokarokaro
  3. Pycnonotus cafer – red-vented bulbul. Locally known as Ulurua or Uluribi
  4. Herpestes javanicus – Small indian mongoose
  5. Sus scrofa – Feral pig
  6. Psidium cattleanum – Strawberry guava or Cherry guava
  7. Gambusia affinis – Western Mosquitofish
  8. Sphagnetifolia trilobata – Wedelia.

These are but a few of the many invasive alien species that have had and continue to have negative impacts on our endangered wildlife.

As custodians of Fiji’s natural heritage, we can begin protecting our endangered species by ensuring that these invasive alien species do not enter our forest ecosystems or our waterways; or by controlling them if they have already invaded the forest.

We can take simple steps such as planting more native and non-invasive trees around our villages and homes, removing invasive alien trees from our villages and homes, not taking invasive alien animals on board inter-island ferries and aeroplanes.

The theme for International Biological Diversity Day in 2010 will be: Biodiversity for Development.