A cluster of dead greater crested terns has been detected in south-west Victoria, marking a suspected second mass mortality event from the deadly H5 bird flu in Australia. The state government announced the discovery on Monday, just hours after federal environment minister Murray Watt confirmed the country's first mass mortality event at Baudin Rocks off South Australia's coast.
Second state affected by suspected bird flu outbreak
Victorian authorities said aerial observations over the weekend identified dead and sick greater crested terns in the Glenelg River estuary near Nelson and across Lawrence Rocks. If samples from these birds test positive, it would confirm the second mass mortality event in Australia from the disease that has devastated wildlife populations globally.
Watt warned that Australia has begun “a long and difficult journey” in dealing with the impacts on wildlife. “I want to level with people: this is the beginning of what is likely to be a long, difficult journey in terms of the impacts on wildlife,” he said on Monday.
CSIRO confirms first mass mortality event
The CSIRO’s Centre for Disease Preparedness confirmed on Monday that samples from five greater crested terns and a silver gull taken at Baudin Rocks tested positive for H5 bird flu. Aerial surveillance over the site identified about 50 dead and 30 sick birds, according to the South Australian government.
Watt acknowledged the difficulty of containing the virus in wild bird populations. “The reality is, you can’t stop native and wild birds flying around, and you can’t stop wild animals moving around, and that will mean more mass mortality events like the one we have now seen,” he said. “What we can do, and what we have been doing, is build up the resilience of the populations of our native birds and mammals.”
Victoria reports increase in dead terns
Victoria’s chief biodiversity officer, James Todd, said the aerial observations were “consistent with what was recently reported in South Australia.” The state’s chief veterinary officer, Dr Graeme Cooke, noted a “clear increase in the number of dead terns along that part of the coast” in the past few days.
“Last week we talked about individual detections; the first cases of the H5 bird flu in Victoria. We are now seeing a change as the disease spreads out and has further impacts,” Cooke said.
The affected region is home to an important breeding colony of Australasian gannets, seal colonies, and the Glenelg estuary and Discovery Bay, an internationally significant wetland site.
New cases in South Australia spark concern
South Australia’s environment minister, Emily Bourke, expressed concern about a confirmed H5 case in a petrel found in the Coorong, a large area of internationally significant wetlands that support waterbirds and migratory species. The migratory petrel was among 18 new cases in SA confirmed by CSIRO on Monday, including samples from six birds at Baudin Rocks.
Other new cases included a silver gull in Glenelg, two greater crested terns at Troubridge Island, a silver gull at Southend, a greater crested tern at Monarto, and six greater crested terns on Pages Islands.
“That confirmed location is of concern because it is where waterbirds are also located,” Bourke said. “So it’s going from seabirds, but also potentially now into where we know a lot of waterbirds are nesting and using this space as a safe haven.”
The rapid escalation of the H5 bird flu in Australia underscores the challenges facing authorities as they monitor and respond to the disease’s spread among native wildlife.
