Australia has reported its first confirmed case of H5N1 avian influenza in a native mammal, detected in a long-nosed fur seal found dead in the coastal town of Beachport, South Australia.
The federal government confirmed the virus in the seal, which showed no signs of injury, as part of ongoing surveillance efforts. The discovery follows Australia’s first detection of H5N1 in migratory seabirds in June, with the virus previously identified in the sub-Antarctic territory of Heard Island in late 2025.
The infected seal belonged to a population of approximately 100,000 individuals in South Australian waters. Authorities noted that more than 13,000 seal pups on Heard Island had died from the virus, while the federal government reported 297 confirmed cases nationwide as of Friday. The outbreak has not been linked to poultry or agricultural sectors in Australia.
Federal Minister for Agriculture Julie Collins stated that the spread of H5N1 in the natural environment makes significant losses inevitable, though the seal’s death did not appear to be connected to other sick or dead marine mammals. Chief Veterinary Officer of South Australia Skye Fruean added that seals in the region would likely have been exposed to high virus levels in their environment.
Australia was the last continent to record H5N1 cases, with the outbreak beginning in migratory seabirds before spreading to native species. The country’s first mass mortality event among seabirds occurred this month, according to federal reports.
