‘Tough decision’ to euthanise 90 surviving stranded whales

The attempt to save a pod of 157 false killer whales stranded on a remote beach has failed as challenging surf conditions forced authorities to abandon rescue efforts and opt for euthanasia instead.

A team of 18 wildlife experts and veterinarians arrived on site near the Arthur River on Tasmania’s west coast on Wednesday morning to find 90 animals still alive after spending up to 48 hours on the beach.

More than 150 false killer whales stranded on a remote beach in Tasmania.Credit: Department of Natural Resources and Environment Tasmania

Tasmania Parks and Wildlife Service incident controller Shelley Graham told reporters the team tried to refloat two animals this morning.

“Unfortunately, we were unsuccessful with that as the ocean conditions were preventing the animals from getting out, and they were continually restranding,” Graham said.

“The conditions for the next two days are forecast to be very similar to today, and it’s really unfavourable for getting the whales out into the water, unfortunately. Following expert veterinary assessment, we have decided that euthanasia is necessary for animal welfare reasons.”

The north-west of Tasmania is a noted hotspot for mass strandings. In 2022, 230 pilot whales stranded further south on the west coast at Macquarie Harbour. The largest mass stranding in Australian history occurred in the same harbour in 2020 when 470 long-finned pilot whales became stuck on sandbars. Most of the beached whales died on both occasions.

An aerial view of the mass stranding on the remote Tasmania beach near Arthur River.Credit: Department of Natural Resources and Environment Tasmania

This is the first mass stranding of false killer whales, a dolphin species, in Tasmania in about 50 years, and the stranding zone included 200 metres of surging tidal water on an exposed beach.

The Parks and Wildlife Service was alerted to the mass stranding by a member of the public on Tuesday evening. Helicopter reconnaissance determined that there were no other whales within 10 kilometres of the stranded pod.

Wildlife biologist Dr Kris Carlyon told reporters the decision to euthanise came after giving the rescue effort “a good crack”, including relocating two animals on a trailer to try to refloat them in a more sheltered section of coastline.

The euthanasia would follow international best practice and be carried out by skilled operators using firearms and specialised ammunition, he said.

An attempt to refloat a whale that became stranded on a beach in Tasmania.Credit: Department of Natural Resources and Environment Tasmania

“It’s rare that we need to do it for all the animals that remain alive on a beach, but we’ve certainly done it in the past, and we have a very skilled team to undertake that job effectively and safely,” Carlyon said. “It’s a tough decision and we’ll be looking after our staff in this – it’s confronting for everyone involved.”

Carlyon said the team would start on Wednesday, but it was a slow process to do it safely and humanely, and it might need to be continued in the morning.

Wildlife scientist Dr Vanessa Pirotta told this masthead mass strandings were much more common with toothed whale and dolphin species, including false killer whales, pilot whales and sperm whales, whereas baleen whales, such as humpbacks, were more likely to be stranded individually.

This could be connected to the way they navigate, Pirotta said, since toothed whales and dolphins use biological sonar, also known as echolocation, to navigate and communicate.

A false killer whale weighs from 500 kilograms to 3 tonnes, compared with 40 tonnes for a humpback, but this did not necessarily make them easier to rescue because there were so many of them.

“The clock of survival starts ticking once they’re on land,” Pirotta said. “The weight of their body is crushing them, which is a horrible thing, and they can overheat as well.”

Carlyon said the stranded animals would be extremely stressed, with their body weight unsupported by the water, unfamiliar noises and bright light.

Mass strandings happened most commonly with highly social species such as pilot whales, which were functionally similar to false killer whales, Carlyon said.

“They have really strong social bonds, and it can be that one individual that’s sick or disorientated can draw the rest of the pod ashore,” he said.

He added that the Tasmanian coastline was complex especially on the west coast where most strandings occurred, and being chased by predators was another possible trigger.

Graham said authorities were yet to decide how to dispose of the carcasses, given the remote location and nearby sensitive Indigenous sites, but would liaise with the community.

Dr Olaf Meynecke, a whale expert at Griffith University, published a study last year highlighting the benefits of towing whale carcasses to deeper waters, choosing locations where they were unlikely to drift back to shore.

There are seven known methods of removing the remains of washed-up whales from our beaches, the most common in Australia being to take them to landfill. Other methods include transporting to a rendering facility for by-products, composting, burials, natural decomposition on the beach, sinking the remains, and using explosives.

“Perished whales provide a substantial nutrient source for marine ecosystems, and strategically placing whale remains offshore can enhance nutrient cycling and foster biodiversity, contribute to carbon removal and marine floor enrichment for up to seven years,” Meynecke said.

With AAP, AP

Get to the heart of what’s happening with climate change and the environment. Sign up for our fortnightly Environment newsletter.