1. Introduction

Australia’s native amphibians are threatened by a pathogenic fungus, Batrachochytrium dendrobatidis, known as amphibian chytrid fungus, which causes the infection known as chytridiomycosis. It appears that the amphibian chytrid was introduced to southeast Queensland in the mid- to late-1970s, and subsequently spread to occupy a zone in eastern Australia from Big Tableland in north Queensland to Melbourne in Victoria. Three other zones of occurrence have been identified: southwestern Western Australia, Adelaide, and more recently Tasmania.

The effects of chytridiomycosis on amphibian populations, particularly those in upland eastern Australia, have been devastating with at least one population driven to extinction, and threatened species status of others worsened. Chytridiomycosis has now been identified in 52 per cent of threatened amphibian species (Appendix A notes amphibian species listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999 and their status with regard to infection with the amphibian chytrid fungus). The level of the threat and its distribution could easily increase by movement of infected amphibians to chytridiomycosis-free areas and consequent escape of B. dendrobatidis into new wild amphibian populations. In addition, B. dendrobatidis can spread independently or with the assistance of amphibians.

‘Infection of amphibians with chytrid fungus resulting in chytridiomycosis’ is listed as a ‘key threatening process’ under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). At the time of listing, the Australian Government Minister for the Environment and Heritage determined that having a threat abatement plan (TAP) was a feasible, effective and efficient way to abate the infection process, and directed a nationally coordinated threat abatement plan be prepared to guide management of the impact of the amphibian chytrid fungus on Australian amphibians.

While eradication of B. dendrobatidis is not possible at present, well developed management plans based on current knowledge can assist in restricting the impact and spread of known infestations of the amphibian chytrid and limit spread to new sites.

This TAP aims to minimise the impact of chytridiomycosis on Australian amphibian populations. The TAP has two broad goals:

1.   To prevent amphibian populations or regions that are currently chytridiomycosis-free from becoming infected by preventing further spread of the amphibian chytrid within Australia.
   

2.   To decrease the impact of infection with the amphibian chytrid fungus on populations that are currently infected.
   

Actions will implement currently available strategies for control of chytridiomycosis, provide for the development of new techniques, conduct national surveys to improve our understanding of the extent of the pathogen in Australia and improve our understanding of the pathogen and its effects. A critical performance indicator will be the stability of currently infected amphibian populations and the continuing chytridiomycosis-free status of amphibians in non-infected regions.