H5N1 Detected in South Australian Dolphin as Macquarie Researchers Withdrawn

A common dolphin found dead near Goolwa on South Australia’s Fleurieu Peninsula has tested positive for H5N1 bird flu, marking the second native mammal species known to have contracted the virus in Australia, according to reporting by The Guardian and South Australian authorities. State testing identified the virus in the recently deceased dolphin, with samples sent to the Australian Centre for Disease Preparedness for further analysis. The case follows earlier H5N1 detections in long-nosed fur seals at Beachport and the Pages Islands. The virus has also been detected in a red fox near Port Adelaide, although the fox is a feral species. South Australia’s Department of Primary Industries and Regions said common dolphins had been assessed by the federal government as being at high risk from bird flu, meaning they could face severe population declines if the virus became established. The department said dolphins and porpoises had contracted H5 bird flu overseas, while noting that dolphins do not commonly eat birds but may sometimes interact with them. The dolphin discovery comes as the federal government prepares to withdraw 24 expeditioners from the research station on sub-Antarctic Macquarie Island, about 1,500 kilometres southeast of Tasmania. Bird flu has not been detected on the island, but large elephant seal colonies are located close to the station buildings. Government risk assessments predicted a high likelihood of a significant mortality event during the coming seal breeding season. Officials said the direct risk to humans remained low, but witnessing large numbers of affected animals could create prolonged psychological stress and other workplace impacts for researchers living in the remote environment. The decision follows drone surveys that detected more than 13,000 dead southern elephant seal pups on Heard Island during 2025 and 2026. Officials said they were exploring ways to monitor Macquarie Island and potentially return researchers in future seasons. South Australia also plans to confirm H5 bird flu cases through local laboratories rather than relying on verification from the national disease preparedness centre. Meanwhile, New South Wales announced plans to vaccinate wild little penguins and said initial trial vaccinations had been given to selected captive bird populations at Taronga Zoo.