Giant blue-grey Sei Whales reappear in Argentina's Patagonian waters after 100 years

Giant blue-grey sei whales have made a triumphant return to the waters off Argentina's Patagonian coast, more than a century after relentless hunting drove them to the brink of extinction in the region.

During the 1920s and 1930s, whaling ships operating along the shores of Argentina and beyond decimated sei whale populations, causing their disappearance from the area.

However, global bans on commercial whaling implemented in recent decades have paved the way for their remarkable recovery.

"They disappeared because they were hunted, they did not become extinct but were so reduced that no one saw them," explained Mariano Coscarella, a biologist and marine ecosystem researcher at Argentina's CONICET scientific agency.

"In this case, it took over 80 years for them to have appreciable numbers for people to realize they were there."

Sei whales, known for their massive size and distinctive blue-grey coloration, breed every two to three years, which has contributed to the slow but steady replenishment of their population over the past century.

Their recent sightings off the Patagonian coast demonstrate the effectiveness of conservation efforts when given sufficient time and commitment.

Last month, Coscarella's team worked to fit some sei whales with satellite trackers to map their migration patterns, with funding from the National Geographic's Pristine Seas project.

They captured remarkable footage of the whales from boats, drones, and underwater, documenting their return to these once-familiar waters. "We can consider this a success of conservation on a global scale," Coscarella stated, crediting the global moratorium on whaling as critical to the species' recovery.