Whale Migration Astonishes Scientists with Record-Breaking Journeys

Record distances travelled by whale populations have been discovered in research published today.

Using citizen science platform Happywhale, researchers analysed 20,000 photographs of whales across the Southern Hemisphere, taken from the 1980s to now.

Scientists used photographs of whale tails, or flukes, to identify individual whales and found that two had travelled across the Pacific Ocean to the other side of South America.

Flukes, like a human fingerprint, are unique to each whale, with pigment patterns, overall shape, scarring or unique marks used for identification.

The study found one whale was photographed in Hervey Bay on the Fraser Coast in 2013 before being photographed off the coast of São Paulo, Brazil, in 2019, a straight-line ocean distance of 14,200 kilometres.

A second whale was first photographed in 2003 at the Abrolhos Bank — Brazil's main humpback whale nursery off the coast of Bahia — among a large, boisterous group of nine adults.

In September 2025, 22 years later, it was spotted alone in Hervey Bay, a travel distance of 15,100km and the longest distance ever documented between sightings of an individual whale.

Griffith University PhD candidate Stephanie Stack, who co-authored the paper published by Royal Society Open Science, said it was generally understood that humpback whales would stay in distinct breeding ground populations.

"There's never been any photographic evidence linking these two populations before," she said.

Ms Stack said travelling to other whale populations would help with genetic diversity as the animals recovered from the impacts of whaling.

She said it was also part of cultural transmission, the way in which whales passed behaviours and knowledge to one another.

"We know that humpback whales spread song from one population to another; we know that this moves across the hemisphere," she said.

"So there have been other lines of evidence that there's some amount of mixing and moving happening, but never before seen with photographic identification."

Citizen science helping research

Marine Scientist with the Oceania Project Wally Franklin said the finding was both surprising and extraordinary.

Dr Franklin said humpback whales from east and west Africa, east and west Australia, and east and west Brazil all migrated to the South Pole.

"It's been an open question for some time as to what degree those whales are mixing down there," he said.

"What [the paper] does illustrate is the opportunity that we scientists are obtaining from getting access to photographic data being submitted to these citizen science platforms."

Ms Stack said using photographs of whales, which had been collated since the 1970s, was a non-invasive way to learn about their lives.

"Anyone who takes a photograph of a whale tail anywhere in the world can upload their photograph to this global platform, and many researchers are contributing their catalogues as well, so they can all be compared to one another."

Ms Stack said a couple of the photographs used to identify the two travelling whales were taken by citizen scientists.

"With this new methodology of global collaboration, we're uncovering so many new things about whales we didn't know before," she said.

While the start and end points have been recorded, Ms Stack said they did not know the whales' route they took or what had happened to them since.

"It's a complete mystery to us, and I think that's wonderful in its own way," she said.

"We still have quite a lot to uncover about humpback whales."