A mass stranding of about 230 whales has occurred at Macquarie Harbour near Strahan on Tasmania's west coast, two years since a similar event in the area.
In a statement, the Department of Natural Resources and Environment Tasmania (NRE Tas) said the whales, which appeared to be pilot whales, were stranded on Ocean Beach, near the harbour entrance, known as Hells Gates.
"It appears about half of the animals are alive," the department said.
It said a team from the department as well as the Environment Tasmania Marine Conservation Program (MCP) was "assembling whale rescue gear and heading to the area", which is remote and a long walk from roads.
"They will work alongside staff from the Tasmania Parks and Wildlife Service and Tasmanian Police at Strahan."
David Midson, general manager of the West Coast Council, urged well-meaning members of the public to stay clear.
"The most important thing, if you're not invited by parks or one of the organisations helping is to stay away. Having extra people can really hinder how they go about their rescue efforts."
The harbour is the site of Australia's worst mass whale stranding on record, which occurred two years ago, also on September 21.
In that event, 470 pilot whales became stranded in the harbour, with all but about 100 of them dying.
Yesterday, there was a separate stranding on King Island in Bass Strait, in which 14 whales died.
The department said its incident response manual had undergone extensive review since the 2020 mass stranding.
It said marine wildlife experts would "assess the scene" at Wednesday's stranding to "plan an appropriate response".
"Stranding response in this area is complex. If it is determined there is a need for help from the general public, a request will be made through various avenues," the department said.
"Whales are a protected species, even once deceased, and it is an offence to interfere with a carcass."
Tasmania Police are managing traffic in the area.
Researchers are unsure as to why whales beach themselves.
Some of the possible explanations include a leading whale "misnavigating" the waterway, a sense of adventure leading the group astray or the animal leading the pod getting frightened and taking an evasive action.
When the 2020 stranding took place, the Department of Primary Industry, Parks, Water and Environment said Tasmania was known for en masse whale strandings, with Strahan, Ocean Beach and Macquarie Harbour appearing to be "a hotspot".
