A rescue operation is underway to save all surviving pilot whales from among the 500 or so that stranded on the coast of the Australian island of Tasmania on Wednesday.
“Our focus is on the animals that are still alive,” said Nic Deka, regional manager of the Tasmania Parks and Wildlife Service, at a press conference. “Mortality has increased, but there are significant numbers that are still alive so we will continue to work with these.”
An estimated 270 whales were first found trapped on a sandbar on Monday. At least a third of them have already died while 25 have been successfully rescued by rescue workers.
Another 200 were discovered on Wednesday in a bay less than ten kilometers from where the first capsule was discovered, Deka said. In total, at least 380 whales have died and 50 have been rescued.
Crews were sent out by boat to assess the situation, Deka added, but most rescuers would continue to focus on the first capsule.
The cause of the bulk stranding has yet to be determined.
However, Nicola Hodgins, policy manager for UK charity Whale and Dolphin Conservation, told NBC News that pilot whales are incredibly social creatures and that if you get sick or twist the wrong way around, others will follow suit, putting the entire capsule at risk.
“You will not allow an animal to be sent to die alone,” she said. “It’s probably just one of the strongest social bonds of all kinds.”
Diseases, algae toxins and extreme weather can cause the whales to deviate from course, Hodgins said. Man-made water noise – from shipping to oil and gas exploration to sonar – can also disrupt the hearing and echo localization of whales.
Australia and New Zealand are both hotspots for whale beaching, Hodgins said. While it’s unusual to find so many in one place, it’s not unprecedented: up to a thousand whales have been stranded together.
Once stranded, the whales have a few days before their organs, which are no longer attached to the water, are damaged, Hodgins said.
“You end up being suffocated by the weight of your own body, which is why it’s an incredibly painful path,” she said.
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Calves that lose their mothers are unlikely to survive in the long term, Hodgins said. And if a significant number of older Matriarchs are lost, it can affect the Pod’s knowledge of migration routes and behavior.
“It’s just heartbreaking, absolutely heartbreaking to see these animals fight,” she said.
Also, because of the strong social ties, the survivors might be determined to return to the rest of the stranded capsule and then get stuck again, Hodgins said. As of Wednesday, Australian officials said it had not done so as the rescued group were safely staying away in deeper water.
The rescuers remained optimistic, said Australian wildlife biologist Kris Carlyon at a press conference.
“I think we have a really good chance of getting more out of the sandbar and through the goals. We’re still very hopeful, “said Carlyon.
The Associated Press contributed to this story.
Matteo Moschella contributed.