Only 35 of 230 beached whales are still alive after a mass stranding on Tasmania’s West Coast as rescue-and-release efforts continue.

Marine conservationists launched a rescue mission on Ocean Beach near Macquarie Harbour, south of Strahan, on Wednesday.

Incident controller Brendon Clark said most of the mammals had died.

“We positioned them overnight, again so that we could assess them this morning, and those ones that have survived – we’ve got approximately 35 surviving animals out on the beach – the primary focus this morning will be on the rescue and release of those animals,” he told reporters on Thursday.

“Unfortunately, we do have a high mortality rate on this particular stranding.”

Five of the 40 animals rescued overnight on Wednesday have died, with the surviving whales described as being confused and disoriented with physiological issues.

Department of Natural Resources and Environment Tasmania conservation experts are working to release about 35 surviving whales at Macquarie Harbour.

Police and aquaculture companies are helping, and a new technique will be trialled using a mechanical aid to lift the animals out of the dry sand.

A rescue team of 50 will attempt to move the mammals via vessel into deep, clear water, to ensure the best chance of survival.

Rescue efforts were suspended overnight for safety reasons, but resumed early Thursday morning.

Mr Clark said the exposed conditions on Ocean Beach contributed to the high death rate.

Planning for the removal and disposal of carcasses is under way.

A pathologist from the department’s Animal Health Laboratories will also arrive on Thursday to assist with animal autopsies.

The stranding is the second in a matter of days, after 14 dead sperm whales washed ashore at King Island on Monday. 

Changes in weather and water temperatures have been cited as possible causes.

Wildlife biologist Kris Carlyon said more deaths were inevitable.

“It’s inevitable we may lose a few more. They have been stranded for over 24 hours. They’re in a highly exposed, stressful location,” he told reporters.

Mr Carlyon said the surviving whales were being stabilised and kept upright, cool and wet.

The incident comes two years after the worst whale stranding in the nation’s history occurred in the same location.

About 470 pilot whales were found beached at Macquarie Harbour and the vast majority died.

There have previously been reports of strandings involving sperm whales and dolphins in the same location.

By Mibenge Nsenduluka in Melbourne

Get the latest news, sport, entertainment, lifestyle, competitions and more delivered straight to your inbox with the Canberra Daily Daily Newsletter. Sign up here.