The South Australian premier, Peter Malinauskas, has declared a “significant escalation” in H5 bird flu in the state after the detection of three mass mortality events involving more than 1,000 greater crested terns.
Malinauskas said the cause of the deaths was presumed to be H5 bird flu.
State authorities were also investigating a suspected case in a little penguin found on Kangaroo Island, with the premier telling the state parliament the development was of “particular concern”.
Separately, the Tasmanian government said it was investigating 28 little penguin deaths on King Island with testing under way to determine whether the birds died of H5 bird flu.
Malinauskas said aerial surveillance on Wednesday detected the three mass mortality events in South Australia, all on offshore islands where H5 bird flu had been detected in recent weeks.
He said more than 1,000 dead crested terns were found across Troubridge Island off the Yorke Peninsula and the Pages Islands – known as North Page and South Page – off Kangaroo Island.
The deaths would represent the biggest detected mass casualty events from suspected H5 bird flu since the deadly strain arrived on the Australian mainland in June. Greater crested terns, a common Australian seabird, have been the most affected local species so far.
The Pages Islands are a known breeding site for a colony of endangered Australian sea lions and long-nosed fur seals are known to visit the islands.
Troubridge Island conservation park is an important breeding area for birds and home to a large colony of little penguins, as well as black cormorants and many crested terns.
Malinauskas said the state’s aerial patrols, involving helicopters, planes and drones with support from field crews, were not limited to coastal sea birds. He said crews also looked for mammals, such as Australian sea lions or long-nosed fur seals, which might be affected by H5 bird flu.
“Fortunately, so far, no mass mortality event … involving mammals has yet been detected or reported,” he said.
He said there remained no detections in poultry or livestock.
At a later media conference, the government said new cases in greater crested terns had also been detected in Flagstaff Hill, McLaren Vale, North Haven in the Adelaide area, Lucky Bay on the Eyre peninsula and Tanunda in the Barossa region.
South Australia’s first confirmed case in a raven had also been detected at Port MacDonnell on the Limestone coast.
Georgie Cornish, the executive director of biosecurity at the Department of Primary Industries and Regions, said the detection in the Barossa illustrates the “movement [of H5 bird flu] from [the] coast inwards”.
Malinauskas said the state would continue to take “every practical and appropriate action available” to protect South Australia’s wildlife, industries and communities.
He told the parliament that broad-scale vaccination of wild birds was “neither practical nor appropriate”, but said the state was considering “targeted vaccination of selected captive and managed populations of our most threatened native birds, where it is safe, feasible and likely to provide a conservation benefit”.
The SA government said on Thursday it had been working with Zoos SA and Cleland wildlife park to prepare to vaccinate priority captive native species, with the vaccination of captive little penguins, orange-bellied parrots, red-tailed black cockatoos, cape barren geese and pelicans under consideration.
The state government was also investigating potential opportunities to vaccinate high-priority at-risk mammals such as Australian sea lions at Seal Bay on Kangaroo Island. While there are no registered vaccines for treating H5 bird flu in mammals, the United States has undertaken experimental trials on a small number of seals.
Late on Thursday, the New South Wales government also confirmed H5 bird flu in seven birds found at Narooma and Merimbula on the state’s south coast. Six of the birds were greater crested terns and one was a giant petrel.
The state government said it was “progressing plans to vaccinate priority captive native species”, including regent honeyeaters and little penguins.
In Tasmania, the state government said aerial surveillance on Wednesday spotted 28 dead little penguins and three dead crested terns at the Port of Grassy on King Island.
The Department of Natural Resources and Environment said samples had been collected and sent for laboratory testing for H5 bird flu, with results expected “during the week”.
“Tasmanians care deeply about our wildlife, and particularly our penguins, so we understand that reports like these may be distressing for the community,” a spokesperson said.
They said staff planned to collect the dead birds on Thursday to reduce the risk of transmission.
