The whales were discovered on Monday afternoon on King Island, part of the state of Tasmania in the Bass Strait between Melbourne and Tasmania’s northern coast, the state department of natural resources and environment said in a statement.
A government Marine Conservation Program team travelled to the island on Tuesday and conducted necropsies of the whales to try to determine their cause of death.
Photos distributed by the department showed whales lying on their sides in shallow water on the rocky shore of the island.
Authorities were planning to conduct an aerial survey to determine whether there were any other whales in the area.
The department said it is not unusual for sperm whales to be sighted in Tasmania and the area where they were discovered on the beach was within their normal range and habitat.
“While further inquiries are yet to be carried out, it is possible the whales were part of the same bachelor pod – a group of younger male sperm whales associating together after leaving the maternal group,” the environment department said.
In the meantime, surfers and swimmers were being warned to avoid the immediate area in case the corpses of the whales attract sharks to the waters nearby.
Two years ago, about 470 long-finned pilot whales were found beached on sandbars off of Tasmania’s west coast in the largest mass-stranding on record in Australia.
After a weeklong effort, 111 of those whales were rescued but the rest died.