The Australian Antarctic Division confirmed on Wednesday it was proceeding with the partial evacuation of Macquarie Island research station after high-pathogenicity H5N1 avian influenza was detected in local seabird and seal populations. The department defended the withdrawal against criticism from expeditioners.

The virus represents the first confirmed arrival of H5N1 in Australian sub-Antarctic territory—a milestone wildlife scientists had warned about for more than a year. Since 2023, the strain has killed tens of thousands of seabirds and marine mammals across South Georgia and the Antarctic Peninsula.

Several expeditioners publicly questioned the evacuation, telling ABC News that the risk to human health was low and that removing staff would disrupt critical conservation and monitoring programmes. The Australian Antarctic Division said the move was precautionary and intended to limit human contact with infected wildlife and reduce biosecurity risks.

Surveillance teams from agriculture and wildlife authorities will remain to track the outbreak's spread through the island's penguin, albatross and elephant seal colonies. Officials from the Department of Climate Change, Energy, the Environment and Water said the detection raised the threat of mainland incursion through migratory birds.

The Australian Antarctic Division prioritises protecting both personnel and the island's recovering ecosystem, which was declared pest-free in 2014 after a decade-long eradication programme.