Mass euthanasia of false killer whales – over 150 stranded on Tasmania’s shore

Over 150 false killer whales, also known as Pseudorca crassidens, were stranded earlier this week on the northwest coast of Tasmania. After assessing the situation, Australian authorities announced on February 19 the commencement of a mass euthanasia, deeming the rescue of the mammals impossible. This is yet another such tragedy in the region.

Whales stranded on the beach

False killer whales (Pseudorca crassidens) are a large species of dolphins, growing up to 5-6 meters in length. Their head and dorsal fin resemble those of oceanic orcas, but they are significantly smaller – hence their name. As highly social animals, they travel in large pods, which can sometimes lead to mass strandings. This week, as many as 157 individuals were found on a Tasmanian beach near the mouth of the Arthur River. This is the first incident of such magnitude in over 50 years.

The first rescue teams arrived at the site on Wednesday, 300 km from the nearest city, Launceston. Dozens of the mammals were already dead by then – the false killer whales had likely been stranded on the sand for 24-48 hours. The rescue operation was hampered by unfavorable weather conditions and difficult beach access, which required four-wheel-drive vehicles.

Despite the challenges, rescuers attempted to tow a few live whales back into the sea. Unfortunately, these efforts were unsuccessful – the animals were unable to cross the 200-meter zone of turbulent waters and were repeatedly washed back ashore by strong waves.

Dozens of whales to be culled

Australian wildlife expert Dr. Vanessa Pirotta explains that when a whale or dolphin gets stranded, their survival clock starts ticking. The longer they remain on land, the lower their chances of survival.

By Wednesday noon, it became clear that despite the rescuers’ efforts, saving the 90 remaining live mammals would be impossible. To relieve them from suffering, representatives of Tasmania Parks and Wildlife Service began euthanizing the surviving animals in the afternoon. This somber procedure continued on Thursday after another 25 whales stopped breathing overnight.

Specialized ammunition was used for euthanasia in accordance with global standards, confirmed marine biologist Dr. Krys Carlyon, who was involved in the culling operation.

No one knows exactly why whales strand themselves in such large numbers. Strong social bonds and trust within the pod certainly play a role. “Something must have drawn them to the shore,” suggested Dr. Carlyon, adding that it could have been prey.

What to do with the carcasses?

By Thursday evening, the bodies of 157 false killer whales remained on the ill-fated Tasmanian beach. This raised the question of what to do with them. In such cases, animal carcasses are often buried directly on the beach, but this process requires heavy machinery. However, this approach is complicated in this instance because the area is an important part of Aboriginal cultural heritage.

Authorities are consulting with local communities on how to proceed. Leaving the carcasses to decompose naturally has not been ruled out, though this process could take up to 12 months and would result in an extremely unpleasant odor. For now, the area remains closed to the public.

Tasmania is a high-risk region for whale strandings – as many as 80% of all mass strandings in Australia occur here. In 2020, around Macquarie Harbour, 470 pilot whales were stranded, marking the worst such tragedy in Australian history. Rescuers managed to return about 100 individuals to the sea. Just two years later, in almost the same location, another mass stranding occurred – this time involving 230 pilot whales. Only 30 of them were saved.

main photo: NOAA / Unsplash