Australia’s bird flu outbreak will inevitably lead to significant wildlife losses as the country enters a dangerous new season when millions of migratory birds are expected to arrive.

Agriculture Minister Julie Collins on Monday confirmed the first case of a H5 bird flu mass mortality event after birds were found sick and dead along South Australia’s coast.

“Sadly, we do know that once the H5 bird flu is spreading in wildlife and the natural environment, it is not possible to avoid significant losses, which is what we’re starting to see now,” she said.

“Australians should expect to see more spread and larger numbers now of wildlife being affected.”

But the minister and experts warned that Australia was entering a heightened risk period during the migratory bird season which could spread the virus through naive breeding populations.

“Over the coming months, we will expect to see many many millions of migratory bird species arrive in Australia,” threatened species commissioner Fiona Fraser said.

“It’s like clockwork every year for some of those species.

“Where they congregate in numbers and mix with other bird species in Australia which may already be infected, there is absolutely increased risk of transmission and further mortality events.”

Australia has now recorded 74 confirmed cases of the H5 bird flu, of which 10 were in Western Australia, 54 in South Australia, two in New South Wales, seven in Victoria, and one in Queensland.

“Whilst this is the first confirmed case of a mass mortality, and obviously a very concerning development, it is not unexpected, and is certainly what we have seen overseas with this type of incursion of the H5,” Ms Collins said.

Environment Minister Murray Watt said the mass mortality event, which was recorded on off an island called Baudin Rocks, about five kilometres south of Cape Jaffa on Friday, was “very sad news”.

It came after local transmission had occurred between a number of greater crested terns in South Australia.

“This is the beginning of what is likely to be a long, difficult journey, in terms of the impacts on wildlife,” he said.

“(What) we’ve now got is a mass mortality event. It is likely we’re going to see more.

“The overseas experience has shown that we can’t stop the spread of H5 bird flu among birds or among mammals.

“The reality is you can’t stop native and wild birds flying around and you can’t stop wild animals moving around.

“That will mean more mass mortality events like the one we have now seen.

“Every bird species is at risk here.”

He said an additional $24 million was released last week across the states, territories, and Commonwealth, in addition to the $113 million already invested from the Albanese government.

Senator Watt said state and territory agriculture and environment ministers met on Friday to discuss the crisis and vowed to continue the collaboration.

Ms Collins said she couldn’t provide modelling on the dollar figure impact the virus could have on Australia’s economy.

However, internally the virus has devastated agricultural sectors, with the United State’s taking a $200 billion hit since the outbreak reached America.

While Australia’s poultry and livestock industry hasn’t been affected, Ms Collins said the government were working with the sectors to mitigate the risk.

Australia’s chief veterinary officer Beth Cookson also issued advice to backyard chicken owners, urging them to enhance their biosecurity.

“The advice that we’ve got for backyard chicken owners is to enhance biosecurity,” she said.

“Essentially, it’s about minimising contact between wild birds and backyard chickens.

“Stopping that mingling, including contamination potentially of food and water sources.

“Having some quarantine periods before introducing new chickens into the flock.

“Also, making sure that there’s good hygiene when handling birds.”

Since the first confirmed case on mainland Australia, in a sick migratory brown skua found at Cape Le Grand National Park near Esperance WA, the dedicated hotline has recorded more than 11,000 community reports and more than a thousands tests have been undertaken.

The Albanese government has vowed to published a list of species most at risk “imminently” to inform the public.

Sick bird reports can be made to the emergency animal disease hotline 1800-675-888 or Birdflu.gov.au