Addressing the Issue of Invasive Species

6.1 Control mechanisms

Theoretically the biological control could be the most preferred and environment friendly method. However, it should be borne in mind that the natural enemy of an invasive specie being imported from somewhere else would itself be an alien specie; therefore its specificity for the particular invasive specie needs to be carefully tested. There are numerous examples of biological control organisms going haywire, attacking non-target native species.

Other practical methods may include mechanical removal of invasives, selective burning of invasive species (if possible), or as a last resort, the use of herbicides or pesticides. In this case, selection should be made for such chemicals, which are least persistent in the natural environment.

6.2 Preventive Methods

Prevention of new invasions is of utmost important in the present era of globalization. The IUCN guidelines for the prevention of Biodiversity loss due to Biological Invasions (Clout & Lowe 1996) suggest the governments to establish "Biosafety authorities" to check the accidental, unintentional and unauthorized introductions; and conduct the cost-benefit analysis of intentional introductions through rigorous Environment Impact Assessment (EIA) and risk analysis. These guidelines suggest that in any case, an alien Specie should not be introduced into a natural ecosystem.

Among unintentional introductions, ballast water of ships is considered as the most important factor which carry 3000 species of freshwater, brackish water and marine organisms daily round the globe (McNeely 1998). The United Nations Convention on the Law of Sea (ratified by Pakistan also) requires the States to take all measures necessary to prevent, reduce and control accidental introduction of alien species into marine environment through ballast water. The IUCN Guidelines suggest various ways for safe disposal of ballast water.

The IUCN Guidelines also stress the need to create awareness on inter-relatedness of human activities and the depletion of biodiversity, for the prevention of biological invasions, with reference to Article 13 of Convention on Biological Diversity on Public Education and awareness.