Prevention
Prevention of introductions is recognised as the first and most cost-effective option to combat invasive species.
Read sections 3.1-3.2 (Introduction & Pathways) in the GISP Toolkit (Wittenberg & Cock 2001) to see why it is recommended that the mainstay of biosecurity should be preventing invasive species entering Australia or any other country. In attempting to prevent invasive species entering a country the GISP advocates the use of an invasion pathway approach to measuring risk rather the species based approach that is the commonly used method. While reading these sections consider the following questions:
- What is the advantage of using the pathway approach that the GISP advocates?
- What are the four pathways for invasive organisms entering and/or becoming naturalised?
The way in which we attempt to prevent the entry of potentially invasive species is different in each country. In the following section we explore the Australian approach, with a focus on plants.
An overview of quarantine in Australia
Preventing the introduction of potentially invasive species is traditionally implemented via a governments quarantine policy. In Australia, Biosecurity Australia (BA) and the Australian Quarantine and Inspection Service (AQIS) are responsible for implementing the Australian Government's quarantine policy with respect to plants and animals.
In an ideal world it would be a relatively simple matter of identifying potentially invasive non-indigenous species and preventing them from being brought into the country; the reality is very different.
Australia is an island that relies heavily on trade, both imports and exports. As a result, quarantine has always been about trying to find a balance between protecting our environment, industry and society from the impact of biological invasions and the need to allow reasonably free trade.
The term used for this current approach is balanced risk. As the term suggests it is a risk assessment with economic and political considerations being given equal consideration with environmental concerns. Whether this approach is really "balanced" is the source of ongoing debate.
In practice only species that do not occur in Australia, and which are assessed to be economically important quarantine pests, can be prohibited from importation. It's worth noting the use of economically and not environmentally important pests in this statement.
This conflict between biosecurity and trade is explored in more detail in Constraints on Good Management.
In the following sections we will examine some of the decision support tools that have been developed to help us decide which organisms we want to try and prevent for entering the country.
Risk Assessment
Deciding what species to let into Australia is based on the risk they pose to the environment, the economy or human health; though not historically, in that order of priority.
In what is risk assessment?, we explore what risk assessment is and look at some of tools that are used in decision support. Read this section to understand the risk assessment approach before finishing the Prevention page.
Are we winning?
In spite of having border quarantine inspection deemed to be one of the most efficient anywhere in the world and policies that inhibit the easy entry of animal and plant material, Australia continues to record exotic pest and disease incursions each year.
In the last 25 years at least 400 previously unreported plant and animal pests and diseases have been recorded in Australia.
The ratio between these plant and animal pest and disease incursions has been approximately 10:1 in favour of plants.
-Malcolm E. Nairn
An Overview of Australia's Biosecurity Record and Future Operating Environment Bio Security - A Future Imperative Conference, Perth WA 2001.
Now that you have been exposed to the WRA tool, move onto 'Weediness is in the eye of the beholder'.