Prevention is better than a cure
The best way of protecting island environments from the impacts of invasive species is to prevent the invasive species getting there in the first place. This will avoid the range of impacts due to invasive species and help retain the environment in its natural state. If we prevent invasions, then invasive species management (the cure) will not be required - saving considerable time and money.
To give the environment time to recover
Most invasive species management projects are completed as the first part of a programme to restore the native environment of a site. Keeping the project site invasive-free after the project will give the environment time to recover to its natural state.
To avoid the spread of other invasives
The last thing a project team wants is to be responsible for the spread of an invasive species at, or the introduction of a new invasive to, the project site. The Biosecurity Plan needs to include plans for preventing the spread of any invasive species throughout the site as well as preventing further introductions.
To ensure the project is a success
If a suitable Biosecurity Plan is not implemented as part of an invasive species management project the likelihood of the project being a long-term success is very low. The project itself may well succeed in removing all (eradication) or most (control) of the target individuals, but if a later invasion occurs, all the good work of the project will be rapidly undone. The fact that a project site already has invasive species present is an obvious indication that viable invasion pathways exist and therefore the island is under continual threat of further invasions by existing and new invasive species. Failure to adequately manage this ongoing threat may result in the failure of any project.
To avoid transporting invasives between project sites and between islands in a country
In any country which has many islands, the invasive species present will vary from site to site. Only some of the islands may have a particular species of invasive and others may have remained invasive species-free. Visitors to a site that has invasive species must always ensure that when leaving the site they do not help to export the species off the site and act as a pathway for the invasive species to invade other sites or other islands. In projects that involve several sites, it is particularly important that the project team takes every precaution to avoid transporting any invasive species from one place to another. Beware – it is very easy for the project team to become a pathway.