Volunteers on Monday joined rescue workers struggling to save the lives of dozens of whales and dolphins stranded on a beach on Australia's west coast, officials said.Around 80 false killer whales and bottlenose dolphins were found beached over more than five kilometres (three miles) in Hamelin Bay, south of the city of Perth."The mass stranding occurred early this morning and of the 80 found stranded only 25 false killer whales have been found alive," the Department of Environment and Conservation said in a statement.Staff and volunteers were working to stabilise the survivors while awaiting equipment to help return them to the sea, spokesman Greg Mair said."Our main priority is to ensure the welfare of the remaining alive whales before we herd them back out to sea," he said."When we will be assisting them back to sea depends on ocean conditions and the strength of the animals, at present ocean conditions are quite dangerous with rough seas and large waves."False killer whales are medium-sized whales with long, slender bodies and narrow, tapered heads with rounded snouts.It is not uncommon for them to strand, the department said, with mass beachings of the species occurring in Western Australia four times in the last two decades.The latest beaching takes the total number of whales stranded around southern Australia and Tasmania in the past four months to more than 400.Earlier this month rescuers saved 54 pilot whales after nearly 200 of the giant creatures beached themselves on King Island off Australia's southern coast.In November, more than 150 pilot whales died after beaching themselves on Tasmania's remote west coast and in January, 48 sperm whales died on a sandbar at the north of the island.The phenomenon of whale strandings and the causes remain the subject of scientific debate.