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Endangered Blue Whales Make a Comeback in Ancestral Home

After half a century of disastrous industrial whaling practices that brought them to the edge of extinction, new research released Thursday shows that Antarctic blue whales have begun to return to the sub-Antarctic regions they used to call home.

(CN) — After half a century of disastrous industrial whaling practices that brought them to the edge of extinction, new research released Thursday shows that Antarctic blue whales have begun to return to the sub-Antarctic regions they used to call home.

For centuries, blue whales served as one of the most abundant creatures known to populate Earth’s oceans. Their astounding size and length made them instantly recognizable staples of the sea and have long been revered by marine biologists and casual oceanic observers alike.

This bounty of blue whales took a turn during the late 19th and early 20th century when industrial whaling saw the creatures hunted to the point of near-extinction and radically reduced blue whale populations worldwide.

Perhaps nowhere was this population decimation more apparent than off the coast of the sub-Antarctic island of South Georgia. While blue whales once thrived in this area, data shows that between 1904 and 1971 alone, 42,698 Antarctic blue whales were killed off the island’s coastline, with the majority of the killings taking place around or before the mid-1930s.

While these whaling practices were banned in the 1960s, they nonetheless ravaged blue whale communities so significantly that blue whales virtually disappeared from the South Georgia region altogether. 

Between 1998 and 2018, surveys from ships in the area tasked with locating blue whales recorded just a single blue whale sighting in the entire 20-year period, leaving many to worry that the animal species would never be able to truly recover from decades of being hunted.

New research suggests, however, that these critically endangered creatures could be poised for a comeback.

In a study published Thursday in Endangered Species Research, researchers report that after an exhaustive analysis of more than three decades’ worth of blue whale monitoring data they believe blue whales are returning to the South Georgia region once again.

A survey of blue whales off the South Georgia coast conducted in February of 2020 reported 58 separate blue whale sightings, roughly half a century after industrial whaling was halted.

Susannah Calderan of the Scottish Association for Marine Science says that while the future of blue whales once looked grim, these new sightings could point to a potentially much more hopeful road ahead.

"The continued absence of blue whales at South Georgia has been seen as an iconic example of a population that was locally exploited beyond the point where it could recover,” Calderan said with the release of the study.

"But over the past few years we've been working at South Georgia, we have become quite optimistic about the numbers of blue whales seen and heard around the island, which hadn't been happening until very recently. This year was particularly exciting, with more blue whale sightings than we ever could have hoped for," she said.

Outside of conducting expeditions to monitor the whales firsthand, researchers have also found themselves having to rely on other means of looking for blue whales due to the inaccessibility and notoriously harsh weather of the region. 

This included using unique audio devices that were built to listen for the low frequency calls blue whales send to each other from across the ocean, devices that can still detect such whale communication even in poor weather conditions.

Researchers also looked into whale sightings that were reported to the South Georgia Museum by local tourists, some of which included photo-evidence of the blue whales themselves.

The study reports that all told, at least 41 blue whales were positively photo identified in the South Georgia region between 2011 and 2020, though none of the confirmed 41 matched any of the 517 whales already recorded in the Antarctic blue whale photo catalog.

While researchers are thrilled to see blue whale populations returning to South Georgia, one question continues to linger: if industrial whaling practices ended over 50 years ago, why has it taken them so long to return to their former home?

"We don't quite know why it has taken the blue whales so long to come back,” Calderan said. “It may be that so many of them were killed at South Georgia that there was a loss of cultural memory in the population, that the area was a foraging ground, and that it is only now being rediscovered."

Researchers say that regardless of why it took blue whales so long to find their way back to South Georgia, they are hopeful that these trends represent a turning point for the species.

Should these numbers continue, researchers are hopeful that future research efforts will help provide crucial information to local communities on how to best assist with the rebounding health of an animal species that was once long feared to be beyond saving.

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Categories / Environment, Science

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