Decades after hunters pushed blue whales to the brink of extinction, a population of the ocean giants has returned to a string of islands that was once a brutal hunting ground.
In the 1960s, Soviet hunters discovered a population of 500 living off the Seychelles' 115 tropical islands and killed them all. They also wiped out an estimated 12,000 pygmy blue whales from the Indian Ocean. While the region became a sanctuary for whales in the late 1970s, the species had not been seen since.
Now researchers have announced they’ve recorded five sightings over the last five years. “Never in my life would I have imagined that the biggest animal on planet earth cruises our oceans here in Seychelles,” researcher Dillys Pouponeau said after their rediscovery.
Blue whales are around the length of three school buses and are the largest animals to have existed
Despite their size, the diet of blue whales is mostly tiny krill
Their natural lifespan is between 80 and 90 years
Experts react to blue whale rediscovery
Co-author Dr Jeremy Kiszka said it was "remarkable to know that the largest animal on earth swims here", but said more funding is needed to further research blue whales.
‘We now need to increase our research efforts to assess the abundance of these blue whales and discover why they are using Seychelles’ waters," the University of Florida biology professor said.
The whales’ presence was confirmed using visual sightings and hi-tech audio recordings of their deep underwater bellows, and these findings were published in the journal Endangered Species Research.
An image supplied to Yahoo by Save Our Seas Foundation, which contributed to the work, shows a whale just metres from tiny D’Arros Island. Another from a film crew which was documenting the research shows another animal from above.
"It turns out if you stop killing animals on mass scales and you give them a chance to rebound, they can recover,” researcher Dr Kate Stafford told BBC.
More wild ocean stories from this week
Are blue whales now safe from threats?
While blue whale numbers are thought to be recovering since the International Whaling Commission agreed to pause commercial whaling in 1982, several threats remain.
Collisions from ships travelling at high speeds are known to kill and injure several whale species including blue whales.
Ocean noise, pollution, climate change and entanglement with fishing nets and traps are also thought to be impacting the animals.
Love Australia's weird and wonderful environment? Get our new weekly newsletter showcasing the week’s best stories.