‘Thrilling’: Unprecedented number of critically endangered blue whales recorded off Antarctic island

After centuries of exploitation, large numbers of whales are returning to old feeding grounds

Since whalers left and tighter regulations on whaling have been agreed, populations have begun to bounce back (Amy Kennedy/British Antarctic Survey)

Scientists have recorded an “unprecedented” number of blue whales around the coastal waters of the sub-Antarctic island of South Georgia.

Just two individuals of the critically endangered species, and largest animal ever to have lived on our planet, were recorded in the area during a survey in 2018. But this year, during a more extensive survey, an extraordinary 36 separate sightings meant a total of 55 blue whales were spotted by the scientists.

The research team, led by the British Antarctic Survey, said: “For such a rare species, this is an unprecedented number of sightings and suggests that South Georgia waters remain an important summer feeding ground for this rare and poorly known species.”

The blue whale population was decimated through the 19th and early 20th centuries, reducing their population by as much as 97 per cent, according to some estimates.

The British Antarctic Survey said when the Norwegian explorer and whaler Carl Larsen first visited the island of South Georgia, he was so impressed by the number of whales there he said “I see them in hundreds and thousands”, and immediately applied for a licence to open a whaling station there.

South Georgia became a key whaling station, with numerous species hunted to the brink of extinction, including blue, humpback and fin whales.

But the resulting collapse of whale populations meant the South Georgia whaling industry became unprofitable by the early 20th century.

According to the South Georgia Heritage Trust, the largest whale ever recorded was processed at the Grytviken whaling station on the island. It was a blue whale caught in 1912, with a length of 33.58m (110ft).

Since the whalers left and tighter international regulations on whaling have been agreed, populations have begun to bounce back, with researchers saying the seas still have the capacity to support large numbers of whales.

Whale hunters are dwarfed by their huge catch, a fin whale, at Grytviken, South Georgia (Getty)

Project leader Dr Jennifer Jackson, a whale ecologist at the British Antarctic Survey, told The Independent the survey broke new ground, enabling scientists to better understand whale populations’ recovery from centuries of hunting.

She said the “researchers were thrilled… It suggests blue whales are returning to their old feeding grounds at South Georgia which suggests it’s still an area with abundant food for them to eat.

“Relative to many other oceans on the planet, the Southern Ocean is still relatively pristine, so it still has capacity to support large numbers of whales.”

She said during the trips, which were the first whale surveys conducted on the south side of the island, the team were fortunate to have aboard Antarctic blue whale expert Paula Olson, who holds the largest photo-identification catalogue of Antarctic blue whales and is currently conducting a new analysis of the animal’s abundance.

Ms Olson said: “Given that it was the first voyage in decades to survey for whales [round the whole island], we truly felt like explorers.”

Abandoned boats and buildings at Grytviken whaling station (Getty)

Although whaling has been carried out by humans for several centuries, industrial whaling only took off in the 20th century. The impact on populations has been colossal. In the 20th century alone, nearly three million cetaceans were wiped out in what may have been the largest cull of any animal – in terms of total biomass – in human history, a 2015 study found.

A new assessment of Antarctic blue whale recovery will be conducted by the International Whaling Commission Scientific Committee next year in order to find out how well the population is recovering from exploitation.