Credit: NASA
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"101 reasons"
It is difficult to pin point the exact reason for each stranding said Ronny Ling, President of whale rescue group ORRCA, which is often the first on the scene of a stranding. "Every time that an animal strands in mass it could be for 101 different reasons," he said.
ORRCA is a non-government organisation that fund a 24 hour, 7 day a week hotline for people to call in the case of a stranding or distressed marine animal. He says most of the calls they receive are for single animals.
"Every part of the coast line in Australia whether it's bays or the open ocean has the potential for an animal to strand," said Ling.
"Normally the open ocean animals are the ones that strand in pods or mass numbers but every species of whale or dolphin has been known to strand singly at least."
Many species of whale and dolphin travel in pods, said Ling, and it's been known for one distressed or ill animal to lead an entire pod into the shore.
"One animal gets into strife and the others come into help it and when they get in strife more animals come in and it sort of pyramids in and then you end up with a lot of animals on a beach," he said.
Catherine Kemper, a marine mammal expert from the Australian Antarctic Division said this was the most likely scenario but that most mass strandings still remain a mystery.
"The reasons for this is probably that these species are not used to being near shore and their social behaviour involves 'following the leader' even if it means to their death," she said.
Ocean currents
Mark Hindell, a marine ecology expert from The University of Tasmania who has been working with marine animals for over fifteen years agreed.
But it's likely that the whales were being brought closer to shore in Tasmania because of changes in the ocean current cycle, he said. Cyclic changes in the oceans currents periodically bring cold, southern Atlantic water closer to Tasmania and bring the whales, specifically pilot and sperm whales close to the coast.
"It's a cycle of about 10-12 years," he explained. "When you are at a peak you will get several years of quite a few strandings and then they will slowly tail off and then they will slowly ramp up again."
Some beaches are more prone to mass strandings because of the place on the migration route and the landscape of the beach itself. Beaches with offshore sandbanks can lead to confusion for whales that suddenly find themselves in shallow water.
"There are some places where there have been multiple strandings over the years and the reason for that is - we are not absolutely sure, but we suspect it is -some beaches are just less safe for whales than other beaches," Hindell said.
Hindell admits that pin pointing a reason for whale strandings is not an exact science. "There's probably as many causes as there are strandings," he said.
Whales have also been known to strand due to illness or disease with toxic algal blooms in California being linked to large numbers of deceased animals washing ashore in the US.
