Seventy whales stranded in Tasmania released, but only 20 remain well enough for rescue
Whale rescuers at one of the world’s largest stranding events on Tasmania’s west coast have now released 70 of the 470 marine mammals into the ocean, with only 20 of those remaining now well enough to be rescued.
Vets at the scene in Macquarie Harbour have recommended four of the long-finned pilot whales be euthanised. The task was being carried out on Thursday morning.
At least 380 have died since the stranding was discovered on Monday. Rescuers are now focusing efforts on 20 remaining whales.
Nic Deka, the coordinator of the rescue from Tasmania Parks and Wildlife Service, said on Thursday morning that the focus was shifting to gathering hundreds of dead whales strewn across sandbanks, bays and floating in the water.
Related: 380 whales dead in worst mass stranding in Australia's history
“We think there are around 20 still viable to release from the sandbar [at Fraser Flats],” he said.
“It is a complex site and many whales are submerged. It’s difficult to assess which are alive and dead. But we have about 20 that we think have the strength to be released.”
Dr Kris Carlyon, a marine conservation program wildlife biologist, said rescuers had tried to release the animals to be euthanised.
“These are animals that we have given them a chance and tried release and they haven’t done well and that’s purely down to the situation they’ve found themselves in.”
A spokesperson for Tasmania’s Department of Primary Industries, Parks, Water and Environment said in statement: “Euthanasia is by firearm with a customised ammunition. This is in line with world best practice for euthanising a whale species of this size.”
The stranding, near the town of Strahan, is one of the largest ever recorded anywhere in the world and the biggest in Australia’s history.
The previous largest stranding, also involving long-finned pilot whales, was at Dunsbrough in Western Australia in 1996 when 320 of the mammals got stuck with only 20 surviving.
Deka said the task of gathering up the dead whales had already started. There were concerns the whales would “bloat and float” and then start to drift, creating a navigation hazard in the harbour.
“They could also attract predators such as sharks and that’s always a risk. The decomposition could also affect oxygen levels in parts of the harbour.”
He said the preference was to tow the animals out into the ocean but it could be several days before tides and currents were favourable. Pilot whales vary in weight depending on age and sex, but can weigh more than a tonne.
A 32-metre barge with a crane attached is due to arrive from the state-owned TasPorts corporation on Monday to help with the salvage. The MV Kulanda, which can carry a 92-tonne load, also has a crane attached.
About 40 government staff, 20 volunteers mostly from the harbour’s fish farming industry, and about 17 surf lifesavers have made up the rescue crew.
Related: Australia whales: rescuers in Tasmania free 25 stranded pilot whales, but 90 already dead
Deka said volunteers were “doing some hard yakka” in the water and everyone was tired, but were “bearing up well under the pressure”.
“My focus is on doing the best job we can. Now it’s looking ahead to collect and dispose of the carcasses.”
Carlyon said it was unlikely they would ever know for sure why the 470 whales made their way into the shallow water and into the harbour.
“The most likely scenario is that something has brought them close to the coast – and most likely that’s food – and then they’ve got themselves into trouble.”
The largest known whale stranding was in 1918 in New Zealand’s Chatham Island when about 1,000 pilot whales stranded.
Pilot whales, which can live up to 40 years, have a strong social bond and travel in groups, with some staying in the same pod for life. Pods can be up to 1,000 strong.
