The fin whales are back.

According to research published Thursday, the whales that were almost exterminated have been found to be back in large numbers at their ancestral feeding grounds off Antarctica’s coast.

Researchers shared for the first-time details about massive feeding frenzy among fin whales close to Elephant Island in Scientific Reports. They saw about 150 whales diving and lunging with wide mouths, gulping down krill.

They also did abundance estimates and found a higher concentration than other areas known for sightings of fin whales in the area.

Research has shown that only 1% to 2 percent of fin whales survived commercial whaling. This began in the Southern Hemisphere early 20th-century and was continued up until the 1970s when restrictions were introduced.

The existence of whales in densely populated waters, where they gathered their food generations ago, suggests that the species is reclaiming this important habitat and that the population has begun to recover.

Researchers wrote that the strong return of the species to the rich feeding grounds with krill was “raising hope” that fin whales were on the way back to pre-exploitation numbers in Scientific Reports.

The video footage of fin whale “aggregation,” according to the researchers, was first shown in a BBC documentary series entitled “Seven Worlds, One Planet”, which was hosted by David Attenborough, a famous British broadcaster and naturalist. Researchers from Scientific Reports collaborated with documentarians to add new data and analysis to the whales.

“I had never seen so many whales at once before and was fascinated watching them feed,” Bettina Meyer (co-author of the study and a biologist at the Alfred Wegener Institute) stated in a news release.

In 2018, the International Union for Conservation of Nature upgraded fin whales from “endangered” status to “vulnerable”. The International Whaling Commission sets global catch limits for commercial whaling.

According to the study, the quota for fin-whale species was reduced to zero in 1976. The commission declared a halt to all commercial whaling in 1982. Japan, Norway, Iceland and Norway have all hunted whales commercially ever since.

Since the early 2000s, scientists and other observers have noticed an increase in fin-whale sightings between South America’s waters and Antarctica. They suspected that the area around Elephant Island was becoming a popular spot for fin whales.

Researchers used a helicopter to measure fin whales’ presence aboard an icebreaker vessel in the Scientific Reports study. Researchers were able to fly above the whales and gather data on their density.

Many species of whales pass on information and habits about their feeding areas through the generations. Research shows that mothers pass this information to their children.

According to the study, generations of fin whales may have lost the location of Antarctic feeding sites because of their population decline and disconnection by whaling.

“… This could indicate that the Antarctic fin whale population is recovering, Meyer stated.