Australian Whale Stranding Now One of the Largest in Recorded History
More than 450 beached whales have been found off Australia’s coast over the past few days, in what is shaping up to be one of the world’s largest recorded stranding events.
Marine conservation experts deployed to Tasmania’s west coast on Monday after some 270 long-finned pilot whales—a species of oceanic dolphin, or “blackfish”, that typically grows to six metres in length can weigh up to 3 tonnes—were discovered washed up in the shallow waters of Macquarie Harbour.
Dozens of the animals were dead by the time the rescue operation got underway, and dozens more perished on Tuesday as 60 odd rescuers desperately tried to figure out how to get the remaining whales off the beach and back out to sea.
Then, on Wednesday morning, a helicopter that was flying over Macquarie Harbour in an attempt to check how many whales were still alive discovered a further 200 washed up about 10 kilometres away—all of which appeared to be dead.
It is the largest stranding event in Tasmania’s history, and Dr Karen Stockin, an associate professor at Massey University in New Zealand, told The Guardian that “it’s fair to say this will probably rank third or fourth globally [in terms of the numbers of stranded animals].”
Rescuers confirmed on Wednesday afternoon that while they managed to save 50 of the whales, at least 380 had died and 30 were still stranded.
It’s not entirely clear what led to the mass stranding, with many experts still unsure why it is that whales beach themselves in general. But according to Dr Chris Wilcox, Marine Ecologist and Chief Research Scientist at CSIRO in Hobart, Tasmania, it’s not unusual. And Tasmania’s west coast is a “global hotspot” for large-scale events.
“It’s caused by a range of things,” Dr Wilcox told VICE News over the phone. “In some cases these events are driven by infections or disease. In other cases people think they can be caused by loud sounds underwater such as air cannons.
“There’s evidence of different causes, so when one of those reasons becomes relevant for a particular pod you can get strandings.”
Long-finned pilot whales are particularly notorious for mass strandings because of the way they travel in packs. They’re social mammals that use echolocation to navigate, and when an individual or couple leading the pod goes one way, the rest are wont to follow.
Speaking to the ABC, Dr Vanessa Pirotta from Macquarie University suggested that Tasmania’s current stranding could be a result of “an individual or couple leading the pod and they have misnavigated”.
“Maybe something startled them,” she said, “or maybe they’re just curious.”
While several experts have insisted that the stranding is a natural event, and ruled out the possibility of some kind of human influence playing a role, Dr Wilcox suggests that more clarity is needed around the causal factors so that communities can try and mitigate the risk as much as possible.
“It would be nice if we understood better what drives these events, and where possible we can reduce any human factors that are contributing to them,” said Dr Wilcox. “I think whale strandings are not wholly driven by human factors, but it would be nice to reduce our impact in any way we can.”
Whatever the cause, there are now hundreds of dead whales in Macquarie Harbour that need to be disposed of in the least impactful way possible: a colossal task for those involved in the cleanup effort.
The main methods of getting rid of whale carcasses typically include dragging them out to sea, taking them to a waste management facility, burying them, or leaving them to decompose—the first three of which will require a huge amount of energy for so many carcasses; the fourth of which is likely to bring sharks to the area.
And as the rescue operation drags on, the number of dead whales in need of removal is only likely to rise.
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Source : Gavin Butler Link