The deadly H5 strain of avian influenza has claimed its first mass wildlife mortality event in Australia, with testing confirming the virus in greater crested terns found on Baudin Rocks, an island located five kilometres off South Australia's south-east coast near Cape Jaffa.

Aerial surveillance detected sick and dead birds on the island late last week, leading to testing that confirmed the presence of the disease. Australia has now recorded 78 confirmed cases of H5 bird flu across five states: 58 in South Australia, 10 in Western Australia, seven in Victoria, two in New South Wales, and one in Queensland.

Spillover Risks and Biosecurity Response

Federal Agriculture Minister Julie Collins acknowledged that the mass die-off was an inevitable outcome once the pathogen entered wild populations. She reiterated that controlling the virus in the natural environment is virtually impossible, though she reassured the public that commercial poultry operations remain unaffected and human health risk stays low.

Authorities have worked closely with the commercial poultry sector to fortify biosecurity protocols and prevent the virus from breaching agricultural facilities. However, officials warn that spillover into broader wildlife populations will continue.

State Impact and Species Vulnerability

Concerns are growing over key ecological havens. In South Australia, a petrel tested positive for the strain in the Coorong wetlands, a crucial breeding site 200 kilometres south of Adelaide. South Australian Environment Minister Emily Bourke expressed deep concern for the vast numbers of water birds nesting in the region.

South Australia's Chief Veterinary Officer, Dr. Skye Fruean, warned that the virus is expected to move through multiple species. While crested terns and silver gulls currently make up the majority of cases, experts anticipate wider species transmission over time.

In Victoria, six new cases were identified in crested terns, bringing the state total to seven. Teams are currently running tests on another cluster of sick and dead birds found in Victoria's south-west near the Glenelg River Estuary, Nelson, and Lawrence Rocks. Victorian Chief Veterinary Officer Dr. Graeme Cooke stated that monitoring teams are working to track how the virus progresses across local populations.

National Action Plan Activated

Federal Environment Minister Murray Watt confirmed that the national response plan for H5 bird flu is now active. An additional $24 million in joint federal and state funding has been released to manage the outbreak, building upon an initial $113 million investment in biosecurity preparedness.

With upcoming migratory seasons expected to bring massive flocks of birds into Australian wetlands, Threatened Species Commissioner Dr. Fiona Fraser cautioned that bird congregations will heighten transmission risks. Efforts are now turning toward building habitat resilience, managing water resources, and suppressing invasive predators like foxes, feral cats, and wild pigs to give native species the best chance of surviving the outbreak.