It’s been a tense week for whale watchers, with the discovery of the carcass of a white humpback whale washed up on a beach near Mallacoota, Victoria.
Could it be the famous Migaloo, a male albino humpback whale that hasn’t been spotted for a few years now? From photographs of the beached cetacean, however, scientists have confirmed that it’s in fact a sub-adult female – not Migaloo.
But what if the whale had been male? How does anyone know one whale from another? And how on Earth can scientists lose a white whale?
Many people have the notion that the majority of whales in the ocean are fitted with devices, known as tags, which help scientists to track them on their global journeys. But this is absolutely not the case.
As marine mammal expert at Macquarie University, Sydney, Dr Vanessa Pirotta explains, whales are rarely tagged: “The process is expensive, logistically challenging – you need people who know how to navigate boats around whales and also how to do the actual tagging.”
Then, of course, there’s the potential harm to the animals themselves. Tagging is invasive, can be risky and there’s also some evidence of behavioural changes amongst individuals and groups in response to being tagged.
Tags are also temporary. Unlike tags in the ears of livestock, for example, the devices aren’t permanent.
“If an animal is tagged, they’re not holding onto the tag forever… they might last for a few hours, to maybe a day or even a few months,’ says Pirotta.
So, in reality, even if Migaloo had a tag when he was last seen two years ago, it’s highly unlikely that he would still be wearing it.
A lot of whale research is done by good, old-fashioned observation, from the shoreline or from boats. Whales are commonly identified by their physical characteristics – skin markings or scarring, the shape of their dorsal fins as they rise out of the water, or even the shape of their tail flukes which, as Pirotta explains, “are just like a human fingerprint, no two flukes are the same”.
One great example of this is ‘Curly’, a whale spotted off the coast of Sydney last month with an incredible helix-like furled tail, which Pirotta believes to be a deformity.
Scientists use observations of a whale’s sex and size to work out its approximate age. Whale babies less than a year old are known as calves, and ‘yearlings’ describes whales that are weaned, which means they eat for themselves, and no longer drink their mother’s milk. Sub-adults – like the female washed up on the beach in Mallacoota – range from the age of two until they reach sexual maturity at around 12–15 years, when they become adults, like Migaloo. (There is no term for a geriatric whale, which is rather civilised.)
So, surely scientists have some whizz-bang way of tracking the whales, knowing where they are generally? Well, not exactly.
The public have a huge part to play in sighting individuals and pods of whales and alerting scientists to their whereabouts. “The reality is that most spotting of whales is by ecotourism boats, and people at a beach just watching whales,” explains Pirotta.
These whales travel huge distances from breeding to birthing grounds, travelling from Queensland all the way down to Antarctica, so there’s a lot of ocean in which they can hide.
When the call comes (for instance, to see Migaloo), says Pirotta, “you drop everything. Maybe even if you’re having a meeting with the Queen, you’d drop that as well to go!”
Sometimes, it’s a long time between drinks. The last time Pirotta saw Curly (before his sighting this year) was in 2016. So, scientists really do rely on citizen scientists in a big way.
“We can’t be on the ocean every single day, but you might be seeing a whale from your morning stroll along the beach, or you might go to a nice exotic destination and see whales there,” says Pirotta. “And any information you gather can be provided to scientists through social media. And that can be really powerful.”
For Pirotta, it’s an opportunity to fly drones through the expelled spray from surfacing whales, looking for lung bacteria in the ejected cloud of water and whale snot – yes, whale snot.
Other scientists are keen to understand more about whales themselves, their biology, behaviours and migratory patterns. We actually know comparatively little about them, generally.
Whales are elusive, diving deep into the vast depths of the ocean. According to the United States’ National Ocean Service, there’s just a smidge over 321,003,271 cubic kilometres of water in the ocean. That’s far more water than whale, and lots of space to hide!
So, how do you lose a whale?
Well, as it turns out, quite easily. The miracle, in truth, is actually in finding them at all.
Clare Kenyon @RedLippedAstro is a science writer for Cosmos. An ex-high school teacher, she is currently wrangling the death throes of her PhD in astrophysics, has a Masters in astronomy and another in education. Clare also has diplomas in music and criminology and a graduate certificate of leadership and learning.
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