Land Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Ann Hamblin, Bureau of Rural Sciences, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06748 5
Introduction of novel biota into native habitats and communities (continued)
Pressure (continued)
Number of port entries [L Indicator 4.1B]
Data from Customs quarterly bulletins gives trends in traffic to sea- and airports, while entries detected at barriers have been obtained from AQIS. Quarantine controls are increasingly based on assessing the level of risk that may be posed by different types of organisms (Quarantine Review Committee 1988).
Figure 44: Total number of air and sea traffic movements at all shipping and airports in Australia, 1991-1999.
Source: Australian Customs Service (unpublished data)
Air and sea traffic has increased significantly at all ports and internally within Australia over the past decade (Figure 44). This increases the risk of further internal dissemination of pests, weed seeds and diseases. Risk analysis has been carried out to assess which pathways are the most likely modes of entry, for example. More interchange now takes place through international mail exchanges, courier depots and air cargo than 25 years ago. Similarly, the places of origin have changed. At one time, most weeds entering Australia were of European origin, but in the past two decades the distribution has been more evenly spread between the Americas (25%), Europe (24%) and Africa (23%), with 13% of unknown origin (Australian Quarantine Review Committee 1996). There has been a worrying increase in the establishment of weeds in the past 25 years. Most reports of incursions and spreading events are from New South Wales, Victoria and Queensland, with a larger number of insects reported from the north and more weeds from the south (Table 22).
| State | Number of events |
|---|---|
| New South Wales | 88 |
| Queensland | 76 |
| Victoria | 75 |
| Western Australia | 40 |
| South Australia | 34 |
| Tasmania | 28 |
| Northern Territory | 23 |
Sources: AFFA; National Offices of Plant and Animal Health (unpublished data).
Implications
Australia's stringent and comprehensive quarantine administration structure, together with its island-continent nature, has protected Australia's vulnerable environments from the worst of the onslaught of exotic incursions in the past few decades. But much damage has already been done from those species that have been deliberately or inadvertently introduced in the earlier days of European settlement. The control of feral vertebrate pests, weeds, insects, and diseases is a constant battle for containment; eradication is not a realistic option in the majority of cases.
Additional pressures are constantly developing from the increased economic activity, which results in more and more air, sea and land transport routes, vessels and visitors. New threats through Internet trading have to be anticipated and will add to the burden of control, but without the current level of effort Australia's biota, as well as agricultural, fisheries and forest industries, would be under threat.