On January 13, 2026, researchers from the conservation group Rewilding Argentina spotted a humpback whale in the waters of Patagonia Azul Provincial Park in Chubut Province, Argentina. She was feeding and diving alongside a companion. They named her Popa — and fitted her with a satellite tag that would go on to record one of the most dramatic journeys ever documented in the South Atlantic.

 

For over a month, Popa remained in the park and surrounding waters, feeding voraciously — ranging as far south as Rocas Coloradas, another key humpback feeding site. Then, at the end of February, something shifted. Between February 24 and March 16, she swam almost without pause, covering the 2,500-kilometer distance to the South Orkney Islands — home to Argentina's Orcadas base, the world's oldest continuously staffed Antarctic station. After resting for several days, she pressed on again toward the Antarctic Peninsula on March 28.

 

The satellite devices used in this kind of research attach temporarily to the whale's skin and transmit GPS locations in real time for weeks or months until the animal's body naturally expels them. Tissue biopsies taken during tagging allow scientists to determine sex, analyze DNA, and compare populations across different regions.

 

Popa's journey is the product of five seasons of systematic monitoring that has transformed what scientists know about this stretch of the Argentine Atlantic coast. Since the programme began in 2021, the number of individually identified humpback whales in the park has grown to 239 — a figure that would have seemed unimaginable when the area had barely any whale records at all.

 

Each whale is identified by the unique shape and markings on its tail fluke — a natural ‘fingerprint’ that allows researchers to build a growing catalogue of individuals. Matches have already been found between whales photographed in Argentina, Brazil, the Beagle Channel, and Antarctica, hinting at movement patterns far more complex than previously recognized. In addition to known oceanic routes, the data suggests a possible third coastal migration corridor closer to shore than scientists had expected.

 

Beltramino describes the park’s significance plainly: “It is probably the site of the highest concentration of humpback whales along the entire Argentine Atlantic coast.” In a single season, more than a hundred individuals were recorded in just one section of the park. The area around Rocas Coloradas, where Popa lingered on her southward journey, has also emerged as a critical secondary feeding ground for the species.

 

 

 

 

Humpback whales are celebrated for their long-distance travel. Research has shown that some populations undertake migrations of more than 8,000 kilometers — the longest annual journey of any mammal on Earth — moving between tropical breeding grounds and polar feeding areas. During transit, whales like Popa may go for months without feeding, relying entirely on the fat reserves built up in rich summer waters.

 

What makes Popa’s case especially valuable to researchers is the continuous, fine-grained data provided by the satellite tag. Scientists were able to observe not just where she went, but how she behaved along the way: the extended feeding phase in Patagonia, the abrupt shift to sustained, almost non-stop swimming, and her eventual arrival and rest in Antarctic waters. This combination of behavioral and geographic detail is rarely captured in a single tracking record.

 

 

 

 

The South Orkney Islands, where Popa made her first Antarctic landfall, are among the most important whale feeding areas in the Southern Ocean. They are also, according to conservation groups, the current epicenter of industrial krill fishing.

 

Antarctic krill — tiny, shrimp-like crustaceans — are the foundation of the Southern Ocean food web. Humpbacks, fin whales, penguins, seals, and seabirds all depend on them. Industrial supertrawlers extract hundreds of thousands of tonnes each year, primarily for omega-3 supplements and fish-farm feed. In 2025, for the first time in history, the Antarctic krill fishery reached its seasonal catch limit of 620,000 tonnes, triggering an early closure and alarming scientists.

 

Research published by the British Antarctic Survey has noted declining pregnancy rates among humpback whales, which scientists link in part to reduced krill availability. The South Orkney Islands and Antarctic Peninsula — Popa’s destinations — are precisely the areas where krill fishing has been most heavily concentrated, following a 2024 decision by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) not to renew catch dispersal rules. Conservation organizations, including Sea Shepherd and Pew Bertarelli, have warned that without stronger protections, the pressure on krill — and on every species that depends on it — will only intensify.

 

For the researchers tracking Popa, her arrival at this flashpoint carries a pointed message. The same waters she swam into to feed are being stripped of their food source by industrial fleets.

 

 

 

 

Popa’s story is already reframing how scientists think about the stretch of ocean between Patagonia and Antarctica. The monitoring program has confirmed that Patagonia Azul is not just a waypoint but a critical feeding ground in its own right — one whose protection matters not only locally but for the health of the broader South Atlantic ecosystem.

 

Each season brings new individuals into the catalog, new matches between distant regions, and new data that inch scientists closer to a complete picture of where humpbacks go and why. The tag on Popa’s back has long since fallen away. But the data it gathered will continue to inform conservation decisions for years to come.