A pod of 34 pilot whales have been found dead on a beach on Tasmania's Freycinet Peninsula on the East Coast.
Local photographer Chris Theobald described the mass beaching as "confronting" in a post on social media on Wednesday.
"Strong social bonds may lead to a herd following a sick or disorientated pod member into trouble, but this particular group died fairly quickly, suggesting they all could have been sick," he wrote.
He said the whales had stranded on Tuesday on Bryans Beach.
"Relentless fishing, pollution and now seismic blasting in our oceans could all be contributors."
There was "no time" to save any of the stranded animals, he wrote.
A government spokesperson confirmed that officials of the Department of Natural Resources and Environment's Marine Conservation Program attended the site of the grounding to investigate.
"Staff, including a wildlife veterinarian, are on site today to assess the situation and sample and measure the carcasses," the spokesperson said.
"It is not known why the whales stranded and is often not possible to determine. Pilot whale strandings are not uncommon in Tasmania."
The public should keep their distance and to report stranded whales or dolphins to the whale hotline on 0427 942 537, the spokesperson said.