A common dolphin. A dead dolphin in South Australia has tested positive for H5N1. Photograph: Dave Irving/Getty ImagesView image in fullscreenA common dolphin. A dead dolphin in South Australia has tested positive for H5N1. Photograph: Dave Irving/Getty ImagesDolphin dies from H5 bird flu in SA as researchers withdrawn from sub-Antarctic island over ‘psychosocial risk’Australian government announces 24 expeditioners based at research station on Macquarie Island will be evacuated over possible ‘prolonged psychological stress’
A dolphin has died from H5 bird flu in South Australia, marking the second native mammal species known to have contracted the virus.
It comes as the federal government announced it would withdraw researchers from the subantarctic Macquarie Island research station due to the “psychosocial risk” of witnessing potential mass seal deaths from H5N1 during the upcoming seal breeding season.
The common dolphin was found recently deceased near Goolwa on the SA’s Fleurieu Peninsula. State tests confirmed the animal was positive for H5N1, with samples sent to the Australian Centre for Disease Preparedness for further analysis.
It follows two earlier detections in long-nosed fur seals in SA at Beachport and the Pages Islands and a case in a red fox – a feral pest species – near Port Adelaide.
The federal government’s risk assessment rated common dolphins at high risk from bird flu, meaning they potentially face severe population declines where the virus takes hold.
“While the detection in the common dolphin is a new development in Australia, there is evidence of dolphins and porpoises catching H5 bird flu overseas,” a spokesperson for SA’s department of primary industries and regions said.
“Dolphins would not commonly eat birds but it is not unusual for them to sometimes interact.”
The federal government said on Friday it would withdraw 24 expeditioners based at the research station on Macquarie Island in the Southern Ocean island about 1,500km south-east of Tasmania.
While bird flu had not yet been detected on the island, it was home to large elephant seal populations close to station buildings. Expert assessments had predicted “a high likelihood of a significant mortality event during the upcoming breeding season”.
“While the risk to humans remains low, a significant mortality event during the upcoming seal breeding season could expose expeditioners to prolonged psychological stress and other workplace impacts,” the department said.
Department deputy secretary Sean Sullivan said: “This is an unusual measure, but is the most appropriate course of action, based on our assessments of risk, and operational realities.”
“Our first priority is the health and safety of our expeditioners. While the risk to humans of H5 bird flu is considered low, we can’t ignore the psychosocial risks of living near potentially large numbers of affected animals,” he said.
Sullivan said the researchers lived and worked in one of the world’s most remote and challenging environments.
“We’ve seen what this disease can do, based on our experience at Heard Island and McDonald Islands.”
Drone surveys detected more than 13,000 dead southern elephant seal pups on Australia’s Heard Island in 2025 and 2026.
Sullivan said the decision had been made to minimise the risks to researchers and “across the whole Antarctic program” in advance of any mass mortality event.
He said Macquarie Island was unique in that thousands of elephant seal pups were born close to the station every spring.
Read more“No other Australian Antarctic station is in this position, and there are no elephant seal colonies on mainland Australia,” he said.
Sullivan said the government was exploring options for monitoring the situation on Macquarie Island, with a view to “returning expeditioners to the station in coming seasons”.
The SA government said on Friday it would move to confirming H5 bird flu cases in the state through local laboratories. Until now, state-based test results have required verification by the CSIRO’s Australian Centre for Disease Preparedness in Geelong. The state government said improvements to its testing processes meant confirmation of H5N1 cases could now be done locally. The New South Wales government also announced its plans to vaccinate wild populations of little penguins at Manly and Barunguba Montague Island. The government will also said “trial cohorts” of some captive bird populations, including little penguins, carnaby’s black cockatoos and red-tailed black cockatoos, had received the first vaccinations at Taronga Zoo this week.
