Now, they're staging a slow comeback, and once-rare sightings of southern right whales are becoming more and more common. But a recent sighting just off the coast of west Australia was a rarity indeed.
Drone footage captured by Department of Parks and Wildlife in Australia's Fitzgerald River National Park shows a birds-eye view of a migrating group of southern right whales.
Among their dark forms casting shadows as they move across the clear water was a strange white spot.
The latest sighting of this unusual-looking calf is a bright spot of hope for the whole species - even though, as he grows, he'll likely change to a lighter shade of grey, according to Doug Coughran, senior wildlife officer with the Department of Parks and Wildlife.
"When you look at big populations of different species, this is one that is really down there, clawing its way back from extinction," Coughran told The Daily Mail.