Before humans began hunting whales, scientists believe that there were around 250,000 blue whales in the Southern Hemisphere. By 1967, when a ban on hunting the blue whale was introduced, that number was down to around 1,500. This ban followed similar bans on whaling of humpback whales, gray whales, right whales, and bowhead whales. Since then, the blue whale was rarely seen. In 1997, official estimates of the blue whale population hovered just north of 2,000. But in February 2020, British Antarctic Survey biologist Dr. Jennifer Jackson reported that the largest mammal to ever grace the planet might be making a big comeback.
Spending almost a month surveying whales in the South Georgia waters, Dr. Jackson and her team were pleasantly surprised to have “very regularly detected” Antarctic blue whales while sighting them on 36 occasions. They estimate having seen 55 blue whales. The team took skin samples from 10 blues and hope this will help them to track their genetic diversity and lineage. All of these things are important to determining population estimates.
The BBC reports that the next official estimate of the species is slated for 2021, and researchers are excited by what they believe to be a pattern of increase for several historically endangered species of whales. Whale populations are attracted to the Antarctic’s South Georgia waters as their food source, krill, moves up there in abundance due to strong currents.
Dr. Jackson told the BBC that one of the reasons she and her fellow researchers are optimistic that this is a positive sign of increase, and not simply a statistical surge, is that there has not been a marked change in the food source. This isn’t a new year where more whales show up because they have been attracted by some unique food chain event. "We know that 100 years ago, South Georgia was a good place for blue whales and now, after decades of protection, it seems the territory's waters are a good place for them once again.”
You can follow the news on blue whales over at Dr. Trevor Branch’s Twitter account here. It’s a good place to see beautiful images like this one:
And this one—though the image is from off the California coast.